Ultrasound Guidance – Selected Indications

Number: 0952

Policy

Aetna considers ultrasound (US) guidance medically necessary for the following procedures (not an all-inclusive list):

Adductor canal nerve block
Arterial line placement
Axillary brachial plexus nerve block
Baker's cyst, after failure of unguided procedure
Breast mass biopsy (see CPB 0269 - Breast Biopsy Procedures)
C5-C7 interscalene nerve block
Carpal tunnel injection
Central venous access (internal jugular, femoral)
De Quervain tendinopathy, after failure of unguided procedure
Elbow joint injection or aspiration, after failure of unguided procedure
Embryo transfer (see CPB 0327 - Infertility)
Endovenous laser ablation of the saphenous vein (ELAS) (see CPB 0050 - Varicose Veins)
Fascia iliaca block for the management of post-operative pain following hip and knee surgeries, and repair of femur fracture
Femoral nerve block for post-operative knee pain
Hepatic mass biopsy
Hip joint injection or aspiration
Iliohypogastric nerve block
Ilioinguinal nerve block
Infraclavicular nerve block for surgery of the distal arm and hand
Intercostobrachial nerve block
Inter-digital neuroma injection
Interscalene nerve block
Intraabdominal or intrapelvic mass biopsy
Intrathecal drug delivery
IPACK nerve block for pain control after anterior cruciate ligament (ACL) repair or total knee arthroplasty
Ischial bursa and gluteus medius injection
Lateral femoral cutaneous nerve block for meralgia paresthetica (lateral femoral cutaneous nerve entrapment) (see CPB 0863 - Nerve Blocks)
Long head of the biceps injection for the treatment of tendinosis of the biceps
Lumbar puncture (see CPB 0628 - Spinal Ultrasound)
Metacarpophalangeal joint injection or aspiration
Metatarsophalangeal joint injection or aspiration
Needle placement, lavage, and debridement of calcific tendinosis of the shoulder
Nephrocutaneous access
Pancreatic mass biopsy
Pectoral nerve blocks (PECS I and PECS II) for post-operative pain control after breast surgery / sternotomy for cardiac surgery
Pectoralis nerve block (PEC 1 and PEC 2) for the management of post-operative pain following mastectomy
Piriformis muscle injection
Placement of vena caval filter (see CPB 0382 - Intravascular Ultrasound)
Placement of intracoronary endoluminal devices (see CPB 0382 - Intravascular Ultrasound)
Popliteal nerve block
Posterior glenohumeral (GH) joint injection or aspiration, after failure of unguided procedure
Pulmonary or thoracic mass biopsy
Prostate biopsy for prosate nodule or elevated PSA (see CPB 0001 - Transrectal Ultrasound)
Quadratus lumborum nerve block for post-operative pain control after abdominal surgery
Radiofrequency endovenous occlusion (VNUS) (see CPB 0050 - Varicose Veins)
Saphenous nerve block
Scapular thoracic bursitis injection
Sciatic nerve block
Serratus plane block for the management of post-operative pain following breast surgery or thoracotomy
Subacromial bursal injection or aspiration, after failure of unguided procedure
Subpectoral nerve block (parasternal T2 to T6 intercostal block) for postoperative pain control
Subtalar joint injection or aspiration
Supraclavicular nerve block for primary regional anesthesia during surgeries, and post-operative pain control
Tibiotalar joint injection or aspiration, after failure of unguided procedure
Thyroid nodule biopsy
Transverse abdominis plane (TAP)-block for the management of post-operative pain following abdominal surgery
Wrist (radiocarpal) joint injection or aspiration, after failure of unguided procedure.

Aetna considers US guidance of no proven benefit for the following procedures (not an all-inclusive list):

Acromioclavicular joint
Adductor longus tendon injection
Ankle bursa injection
Botulinum toxin injection for the treatment of limb and paraspinal spasticity, migraine or cervical dystonia
Calcaneal/retrocalcaneal bursa injection
Clavi-pectoral fascial plane block
Costochondral joint
Dorsal compartments of the wrist injection
Dorsal scapular nerve block
Endovascular treatment of subclavian artery disease (see CPB 0382 - Intravascular Ultrasound)
Epidural injections, including the transforaminal approach (see CPB 0016 - Back Pain - Invasive Procedures)
Erector spinae plane (ESP) block for the management of post-operative pain (see CPB 0863 - Nerve Blocks)
Facet joint injections (see CPB 0016 - Back Pain - Invasive Procedures)
Foot/heel injection for adventitious bursitis/capsulitis
Ganglion cyst injection of the wrist/wrist injection,
Gluteal nerve injection
Gluteal tendon sheath injections for hip and/or low back pain
Hydrodissection of infrapatellar saphenous nerve
Iliopsoas bursa injection
Iliopsoas tendon / tendon sheath injection
Iliotibial (IT) band hydrodissection / IT band injection for IT band pain
Intercostal nerve block
Intraarticular injection for the management of shoulder impingement/pain
Knee joint (except in morbidly obese individuals (BMI > 40))
Lateral pericapsular nerve group (PENG) nerve block during total hip arthroplasty
Lavage of the shoulder joint
Ligament sheath injections
Lumbar plexus block with hydrodissection
Medial calcaneal nerve sheath injection
Median nerve block
Metatarsophalangeal and/or metatarsal cuneiform joint injection for the treatment of plantar fibromatosis (Ledderhose disease)
Needle placement during aortography
Nuchal ligament and supraspinous ligament injection
Occipital nerve block (see CPB 0863 - Nerve Blocks)
Percutaneous bursectomy of the pretibial tubercle bursa
Percutaneous tenotomy of the gluteus medius tendon for the treatment of hip tendinopathy
Peritendon injection for the treatment of Achilles tendinopathy
Peroneal tendon sheath injection
Plantar fasciitis injections
Posterior tibial nerve block for plantar fasciitis
Psoas tendon injection
Sacroiliac joint injection (see CPB 0016 - Back Pain - Invasive Procedures)
Saphenous vein access
Scar tissue injection after Dupuytren's cord excision surgery
Sclerotherapy for varicose veins (see CPB 0050 - Varicose Veins)
Subacromial bursitis injection
Superficial radiation treatment of skin cancer
Superior cluneal nerve injections
Tarsal tunnel injection
Tendon injections (other than those listed as medically necessary above)
Tenotomy for the treatment of lateral epicondylitis
Tibiofibular joint injection
Trigger finger injection/trigger finger release with or without hydrodissection
Trigger point injections (see CPB 0016 - Back Pain - Invasive Procedures)
Trochanteric bursa injections
Viscosupplement injections (see CPB 0179 - Viscosupplementation).

Background

In the past 10 years, ultrasound (US) has become increasingly popular to image both peripheral musculoskeletal and axial structures. Presently, US is often used to guide interventions such as aspiration, hydrodissection, tenotomy, as well as diagnostic or therapeutic injections (e.g., epidural, facet joint, intra-articular, sacroiliac joint, subtalar joint, trigger point and viscosupplement injections). This clinical policy bulletin describes some of the medically necessary as well as experimental/investigational indications associated with the use of US guidance.

Ultrasound Guidance: Medically Necessary Indications

Adductor Canal Nerve Block

An UpToDate review on "Lower extremity nerve blocks: Techniques" (Jeng and Rosenblatt, 2019a) states that "The saphenous nerve is the terminal sensory branch of the femoral nerve. The saphenous nerve block is useful for ambulatory surgeries of the superficial, medial lower leg and provides analgesia of the medial ankle and foot. It can be blocked at the level of the tibial tuberosity below the knee, above the knee using the adductor canal block, or at the ankle as part of an ankle block. Adductor canal block – The saphenous nerve is blocked at the level of the mid-thigh with the adductor canal block using ultrasound guidance … Ultrasound-guided adductor canal block – The ultrasound probe is placed perpendicular to the thigh at the midpoint between the anterior superior iliac spine and the base of the patella. The nerve is identified as it lies adjacent to the femoral artery. It is followed distally as it becomes more superficial, traveling with an arterial branch just deep to the sartorius muscle. Using an in-plane approach, after negative aspiration, 10 ml of local anesthetic (LA) is injected deep to the sartorius muscle, at the lateral border of the artery".

Manickam et al (2009) noted that saphenous nerve (SN) block can be technically challenging because it is a small and exclusively sensory nerve. Traditional techniques using surface landmarks and nerve stimulations are limited by inconsistent success rates. In a prospective study, these researchers examined the feasibility of performing an ultrasound (US)-guided SN block in the distal thigh. After the research ethics board's approval and written informed consent, a total of 20 patients undergoing ankle or foot surgery underwent ultrasonography of the medial aspect of the thigh to identify the SN in the adductor canal, as it lies adjacent to the femoral artery (FA), deep to the sartorius muscle. An insulated needle was advanced in plane under real-time guidance toward the nerve. After attempting to elicit paresthesia with nerve stimulation, 2 % lidocaine with 1:200,000 epinephrine (5 ml) and 0.5 % bupivacaine (5 ml) were injected around the SN. The SN was identified in all patients, most frequently in an antero-medial position relative to the FA, at a depth of 2.7 +/- 0.6 cm and 12.7 +/- 2.2 cm proximal to the knee joint. Complete anesthesia in the SN distribution developed in all patients by 25 mins after injection. The authors concluded that in this small, descriptive study, US-guided SN block in the adductor canal was technically simple and reliable, providing consistent nerve identification and block success.

Messeha (2016) stated that lumbar plexus block, combined with a sciatic nerve block, is an effective loco-regional anesthetic technique for analgesia and anesthesia of the lower extremity. These researchers compared the clinical results outcome of the adductor canal block versus the psoas compartment block combined with sciatic nerve block using real time US guidance in patients undergoing elective laparoscopic knee surgeries. A total of 90 patients who were undergoing elective laparoscopic knee surgeries were randomly allocated to receive a sciatic nerve block in addition to lumbar plexus block using either an adductor canal block (ACB) or a posterior psoas compartment approach (PCB) using 25-ml of bupivacaine 0.5 % with adrenaline 1:400,000 injection over 2 to 3 mins while observing the distribution of the local anesthetic in real time. Successful nerve block was defined as a complete loss of pinprick sensation in the region that is supplied by the 3 nerves along with adequate motor block, 30 mins after injection. The degree of motor block was evaluated 30 mins after the block procedure. The results of the present study showed that the real time US guidance of PCB is more effective than ACB approach. Although the sensory blockade of the femoral nerve achieved equally by both techniques, the LFC and OBT nerves were faster and more effectively blocked with PCB technique. Furthermore, PCB group showed significant complete sensory block without need for general anesthesia, significant decrease in the post-operative visual analog scale (VAS) and significant increase time of 1st analgesic requirement as compared to the ACB group. The authors concluded that the findings of this study showed that blockade of lumber plexus by psoas compartment block was more effective in complete sensory block without general anesthesia supplementation in addition to decrease post-operative analgesic requirement than adductor canal block. The subjects in this study underwent laparoscopic knee surgeries, not ankle surgeries.

The authors stated that this study had several drawbacks. The exclusion of obese patients led to that the incidence of success in patients with body mass index (BMI) of greater than 35 kg/m2 could not be determined, as US visibility of the lumbar paravertebral structures in obese patients was poorer than that observed in patients with low BMI. Another limitation was the wide range of age group and changes in musculoskeletal structures, especially in the elderly patients (greater than 65 years of age) that could reduce the contrast between a peripheral nerve and its surrounding muscles and could adversely affect the quality of US images. Furthermore, patients with abnormal spinal anatomy, due to either spinal deformity or history of previous back or spine surgery also demonstrated poor image quality.

Axillary Brachial Plexus Nerve Block

Klaastad and co-workers (2009) noted that many of the reports concluded that US guidance may provide a higher success rate for brachial plexus blocks than guidance by nerve stimulator. However, the studies were not large enough to conclude that US will reduce the risk of nerve injury, local anesthetic toxicity or pneumothorax. Ultrasound may reveal anatomical variations of importance for performing brachial plexus blocks. For post-operative analgesia, 5 ml of ropivacaine 0.5 % has been sufficient for an US-guided interscalene block. For peri-operative anesthesia, as much as 42 ml of a local anesthetic mixture was calculated to be appropriate for an US-guided supraclavicular method. For the future, these investigators noticed that 3D- and 4D-US technology may facilitate visualizing the needle, the nerves and the local anesthetic distribution. Impedance measurements may be helpful for nerve blocks not guided by US. The authors concluded that the literature gave a sufficient basis to recommend the use of US for guidance of brachial plexus blocks.

Nadeau and associates (2013) reviewed the main US-guided approaches used for regional anesthesia of the upper limb. The anatomical configuration of the upper limb, with nerves often bundled around an artery, makes regional anesthesia of the arm both accessible and reliable. In-depth knowledge of upper limb anatomy is needed to match the blocked territory with the surgical area. The interscalene block is the approach most commonly used for shoulder surgery. Supra-clavicular, infra-clavicular, and axillary blocks are indicated for elbow and forearm surgery. Puncture techniques have evolved dramatically with US guidance. Instead of targeting the nerves directly, it is now recommended to look for diffusion areas. Typically, local anesthetics are deposited around vessels, often as a single injection. Phrenic nerve block can occur with the interscalene and supra-clavicular approaches. Ulnar nerve blockade is almost never achieved with the interscalene approach and not always present with a supra-clavicular block. If US guidance is used, the risk for pneumothorax with a supra-clavicular approach is reduced significantly. Nerve damage and vascular puncture are possible with all approaches. If an axillary approach is chosen, the consequences of vascular puncture can be minimized because this site is compressible. The authors concluded that upper limb regional anesthesia has gained in popularity because of its safety profile and effectiveness associated with US-guided techniques.

Xu and colleagues (2017) examined the safety and efficacy of bilateral axillary brachial plexus block under US-guidance or neurostimulator-guidance. From February 2012 to April 2014, a total of 120 patients undergoing bilateral hand/forearm surgery were anesthetized with bilateral axillary brachial plexus block. All patients were divided into 2 groups randomly using random number table: the US-guided group (group U, n = 60) and the neurostimulator-guided group (group N, n = 60). The block was performed with 0.5 % ropivacaine. Patients' age, sex and operation duration were recorded. Moreover, success rate, performance time, onset of sensor and motor block, performance pain, patient satisfaction degree and the incidence of related complications were also documented. Venous samples were collected at selected time-points and the total and the plasma concentrations of ropivacaine were analyzed with HPLC. The performance time, the onset of sensor block and the onset of motor block of group U were (8.2 ± 1.5), (14.2 ± 2.2)and (24.0 ± 3.5) mins, respectively, which were markedly shorter than those in group N ( (14.6 ± 3.9), (19.9 ± 3.8), (28.8 ± 4.2) mins, respectively), and the differences were statistically significant (t = 11.74, 10.09, 6.73, respectively, all p < 0.01). The performance pain score of group N was (25.5 ± 13.2), which was obviously more serious than group U (31.7 ± 11.2) and a significant statistical difference was detected (t = 2.856, p < 0.05). The patient satisfaction degree of group U was 95.0 %, which was significantly higher than group N (83.3 %) and a markedly statistical difference was detected (χ(2) = 4.227, p < 0.05); 50 mins after performance, the total plasma concentration of ropivacaine of group U was (1.76 ± 0.48 mg/L), which was significantly lower than group N (1.88 ± 0.53 mg/L) and a significant statistical difference was detected (t = 2.43, p < 0.05), while no significant differences were detected at the other time-points between 2 groups (p > 0.05). No analgesic was super-added and no other anesthesia methods were applied. No complications were detected peri-operatively. The authors concluded that the bilateral axillary brachial plexus block under US-guidance or neurostimulator-guidance were both safe and effective for bilateral hand/forearm surgery. However, the US-guided block may be more clinically beneficial because of its shorter performance time, rapid onset and higher patient satisfaction degree.

Li and associates (2020) stated that neurostimulator-guidance and US-guidance are 2 major methods that have been widely accepted and applied in axillary brachial plexus block. However, the differences between the effects of these 2 types of guidance still need to be further elucidated for clinical usage. This study included a total of 208 patients undergoing elective upper limb surgeries and receiving axillary brachial plexus block. The patients were randomly assigned to receive either US-guidance (group U, n = 112) or nerve stimulation (group N, n = 96). Pinprick test was performed for assessing the sensory blockades. The pain was evaluated by visual analog scale (VAS). Reactive oxygen species (ROS) levels were measured by dichloro-dihydro-fluorescein diacetate staining and serum levels of nitric oxide (NO), nitric oxide synthases (NOS), tumor necrosis factor (TNF)-α, and monocyte chemoattractant protein 1 (MCP1) were evaluated by ELISA. Results showed that US-guidance significantly enhanced the quality of the sensory blockade and reduced the VAS scores when compared with the neurostimulator-guidance. In addition, the production of ROS, NO, NOS, TNF-α, and MCP-1 were significantly alleviated by US-guidance. The authors concluded that US-guided brachial plexus block relieved pain during operation, provided higher success rates in the nerve block, caused less vascular damage and resulted in lower levels of inflammatory cytokines secretion when compared with neurostimulator-directed brachial plexus blockage.

C5-C7 Interscalene Nerve Block

In a prospective, randomized, triple-blinded study, Fredrickson and Price (2009) tested the hypothesis that a 48-hour continuous C5-C6 root/superior trunk patient-controlled infusion of ropivacaine 0.4 % would provide superior analgesia after shoulder surgery compared with the same infusion of ropivacaine 0.2 %. Patients presenting for painful shoulder surgery were recruited. A perineural catheter was placed under ultrasound (US) guidance immediately adjacent to the C5-C6 roots/superior trunk. Ropivacaine 5 mg ml(-1) (30 ml) was administered via this catheter before surgery under general anesthesia. At the end of surgery, patients were randomized to receive ropivacaine 2 mg ml(-1) (0.2 %) (n = 32) or 4 mg ml(-1) (0.4 %) (n = 33) via an elastomeric pump delivering 2 ml h(-1) with on-demand patient-controlled boluses of 5 ml as needed. Acetaminophen and diclofenac were administered if any post-operative pain occurred, ropivacaine boluses for a numerical rating pain score (NRPS, 0 to 10) of greater than 2, and rescue tramadol for an NRPS greater than 3. All patients were phoned on post-operative days 1 and 2 and questioned for indices of treatment effectiveness and adverse effects. NRPS, patient ropivacaine demands, and supplemental tramadol consumption were similar in each group [median “average daily pain” days 1/2 (0.2 % = 1/3, 0.4 % = 2/3)]. Episodes of an insensate/densely blocked arm occurred only with ropivacaine 0.4 % (5 versus 0 episodes, p = 0.05). Satisfaction (numerical rating scale, 0 to 10) was higher for ropivacaine 0.2% (mean difference [MD] 1.3; 95 % confidence interval [CI]: 0.3 to 2.4; p = 0.01). The authors concluded that after major shoulder surgery, ropivacaine 0.2 % at 2 ml h(-1) with on-demand 5 ml boluses administered via an US-guided C5-6 root/superior trunk peri-neural catheter produced similar analgesia, but higher patient satisfaction compared with ropivacaine 0.4 %.

Shin et al (2011) stated that continuous interscalene block has been known to improve post-operative analgesia after arthroscopic shoulder surgery. In a prospective study, these investigators examined the US-guided posterior approach for placement of an interscalene catheter, clinical efficacy and complications after placement of the catheter. A total of 42 patients undergoing elective arthroscopic shoulder surgery were included in this study and an interscalene catheter was inserted under the guidance of US with posterior approach. With the in-plane approach, the 17-G Tuohy needle was advanced until the tip was placed between the C5 and C6 nerve roots. After a bolus injection of 20-ml of 0.2 % ropivacaine, a catheter was threaded and secured. A continuous infusion of ropivacaine 0.2 % 4 ml/hour with patient-controlled 5-ml boluses every hour was used over 2 days. Difficulties in placement of the catheter, clinical efficacy of analgesia and complications were recorded. All patients were monitored for 48 hours and examined by the surgeon for complications within 2 weeks of hospital discharge. Easy placement of the catheter was achieved in 100 % of the patients and the success rate of catheter placement during the 48-hour period was 92.9 %. Post-operative analgesia was effective in 88.1 % of the patients in the post anesthetic care unit (PACU). The major complications included nausea (7.1 %), vomiting (4.8 %), dyspnea (4.8 %) and unintended vascular punctures (2.4 %). Other complications such as neurologic deficits and local infection around the puncture site did not occur. The authors concluded that US-guided interscalene block with a posterior approach was associated with a success high rate in placement of the interscalene catheter and a low rate of complications; however, the small sample size limited these researchers to draw definite conclusions; thus, a well-designed randomized controlled trial (RCT) is needed to confirm these preliminary findings.

Finlayson et al (2014) stated that US guidance offers an alternative to fluoroscopy for medial branch blocks of the upper cervical spine; however, it may be less accurate for blocks at the C5 and C6 levels. These researchers hypothesized that a modified technique using biplanar US imaging would facilitate level identification and provide greater accuracy for the lower cervical spine. A total of 40 patients with chronic neck pain underwent US-guided blocks of the C5 and C6 medial branches. For each level, 0.3-ml of a local anesthetic/iodinated contrast mixture was injected. Postero-lateral in-plane needle placement was performed in a transverse view, and the position of the needle tip was verified in the coronal plane using the C7 transverse process as a sonographic landmark. Contrast distribution, as assessed by a blinded observer on antero-posterior and lateral x-ray views, constituted the primary outcome. Secondary outcomes were performance time and pain relief 30 mins after the blocks; 100 % and 97.5 % of C5 and C6 levels, respectively, demonstrated appropriate contrast distribution. The C7 transverse process was readily identified in the coronal plane in all but 2 subjects. Performance time was 248.8 ± 82.7 seconds; the mean percentage of relief provided by the blocks was 76.9 % ± 25.5 %. In 30 % of patients, a blood vessel was visualized crossing the C6 articular pillar and successfully avoided during needle insertion. The authors concluded that US guidance using a biplanar approach was a reliable imaging modality for C5 and C6 medial branch blocks.

Falyar et al (2016) noted that US-guided selective C5 nerve root blocks have been described in several case reports as a safe and effective means to anesthetize the distal clavicle while maintaining innervation of the upper extremity and preserving diaphragmatic function. In this study, cadavers were injected with 5-m of 0.5 % methylene blue dye under US guidance to examine possible proximal and distal spread of injectate along the brachial plexus, if any. Following the injections, the specimens were dissected and examined to determine the distribution of dye and the structures affected. One injection revealed dye extended proximally into the epidural space, which penetrated the dura mater and was present on the spinal cord and brainstem. Dye was noted distally to the divisions in 3 injections. The anterior scalene muscle and phrenic nerve were stained in all 4 injections. It appeared unlikely that local anesthetic spread was limited to the nerve root following an US-guided selective C5 nerve root injection. Under certain conditions, intrathecal spread also appeared possible, which has major patient safety implications. Additional safety measures, such as injection pressure monitoring, should be incorporated into this block, or approaches that are more distal should be considered for the acute pain management of distal clavicle fractures.

Furthermore, an UpToDate review on “Interscalene block procedure guide” (Wilson and Klesius, 2021) provides the following information:

The interscalene block (ISB) targets the interscalene groove between the anterior and middle scalene muscles at the level of the sixth cervical vertebra;
The ISB usually anesthetizes the C5 to C7 nerve roots, as well as the supraclavicular branches of the cervical plexus (C1 to C3), and usually spreads to block C7;
The ISB is a reliable block for shoulder surgery and distal clavicle surgery.

Ultrasound versus nerve stimulation guidance: We use ultrasound guidance for ISB, and occasionally use nerve stimulation to confirm the needle tip location if the ultrasound image is unclear or difficult to obtain. Ultrasound guidance improves the quality of ISB for surgical anesthesia compared with nerve stimulation guidance, but similar quality and duration of postoperative analgesia.

Fascia Iliaca Block for the Management of Post-Operative Pain Following Hip and Knee Surgeries, and Repair of Femur Fracture

In a meta-analysis, Wang et al (2017) compared the safety and efficiency between femoral nerve block (FNB) and fascia iliaca block (FIB) for post-operative pain control in patients undergoing total knee and hip arthroplasties. These investigators carried out a systematic search in Medline (1966 to 2017.05), PubMed (1966 to 2017.05), Embase (1980 to 2017.05), ScienceDirect (1985 to 2017.05) and the Cochrane Library. Inclusion criteria:

Participants: Only published articles enrolling adult participants that with a diagnosis of end-stage of osteoarthritis (OA) and prepared for unilateral total knee arthroplasty (TKA) or THA;
Interventions: The intervention group received FIB for post-operative pain management;
Comparisons: The control group received FNB for post-operative pain control;
Outcomes: VAS scores in different periods, opioids consumption, length of stay (LOS) and post-operative complications;
Study design: clinical RCTs were regarded as eligible in this study.

Cochrane Hand book for Systematic Reviews of Interventions was used for assessment of the included studies and risk of bias was shown. Fixed/random effect model was used according to the heterogeneity tested by I2 statistic. Sensitivity analysis was conducted and publication bias was assessed. Meta-analysis was performed using Stata 11.0 software. A total of 5 RCTs including 308 patients met the inclusion criteria. The present meta-analysis indicated that there were no significant differences between groups in terms of VAS score at 12 hours (SMD = -0.080, 95 % CI: -0.306 to 0.145, p = 0.485), 24 hours (SMD = 0.098, 95 % CI: -0.127 to 0.323, p = 0.393), and 48 hours (SMD = -0.001, 95 % CI: -0.227 to 0.225, p = 0.993). No significant differences were found regarding opioid consumption at 12 hours (SMD = 0.026, 95 % CI: -0.224 to 0.275, p = 0.840), 24 hours (SMD = 0.037, 95 % CI: -0.212 to 0.286, p = 0.771), and 48 hours (SMD = -0.016, 95 % CI: -0.265 to 0.233, p = 0.900). In addition, no significant increase of complications was identified between groups. The authors concluded that there was no significant differences of VAS scores at 12 to 48 hour and opioids consumption at 12 to 48 hour between 2 groups following total joint arthroplasty. No increased risk of nausea, vomiting and pruritus was observed in both groups. These investigators stated that FNB provided equal post-operative pain control compared with FIB following total joint arthroplasty. Both of them could reduce the consumption of opioids without severe adverse effects.

Gao et al (2019) stated that optimal pain management after total hip arthroplasty (THA) remains controversial. These researchers carried out a meta-analysis from randomized controlled trials (RCTs) to examine the safety and efficacy of fascia iliaca compartment block (FICB) in THA. They conducted electronic searches of PubMed, Medline, Cochrane library, and Web of Science before February 2019. These researchers collected RCTs to compare FICB and placebo for pain control after THA. The outcome measurements consisted of pain score, opioid consumption, length of hospitalization and post-operative complications. All data analyses were conducted using STATA 13.0. Cochrane Collaboration's tool was adopted to assess the risk of bias. A total of 7 RCTs met the inclusion criteria with 165 patients in the FICB groups, and 160 patients in the placebo groups. The present meta-analysis indicated that there were significant differences between the groups in terms of pain score at post-operative 12 hours (weighed mean difference [WMD] = -0.285, 95 % confidence interval [CI]: -0.460 to -0.109, p = 0.002) and 24 hours (WMD = -0.391, 95 % CI: -0.723 to -0.059, p = 0.021). FICB was associated with significant superior in opioid consumption at post-operative 12 hours (WMD = -5.394, 95% CI: -8.772 to -2.016, p = 0.002) and 24 hours (WMD = -6.376, 95 % CI: -10.737 to -2.016, p = 0.004) compared with placebo. No significant difference was identified regarding length of hospitalization (WMD = 0.112, 95 % CI: -0.125 to 0.350, p = 0.354). The authors concluded that fascia iliaca compartment block was effective for pain relief during the early post-operative period after THA. Meanwhile, it reduced the cumulative morphine consumption and the risk of opioid-related adverse effects.

In a meta-analysis, Cai et al (2019) examined the effect of FICB on pain control and morphine consumption in patients with THA. These investigators searched databases (PubMed, Embase, Cochrane Library) for eligible randomized controlled trials (RCTs) published prior to September 12, 2018. They only included THA patients who received FICB versus placebo for pain control. Risk ratios (RRs), standard MD (SMD) and 95 % CI were determined. Stata 12.0 was used for the meta-analysis. A total of 326 THA patients from 7 RCTs were subjected to meta-analysis. Overall, FICB was associated with lower visual analog scale (VAS) scores at 1 to 8 hours and 12 hours compared with placebo (p < 0.05). However, there was no significant difference between VAS at 24 hours (SMD = -0.56, 9 5% CI: -1.42 to 0.31, p = 0.206) and 48 hours after THA (SMD = -0.82, 95 % CI: -2.07 to 0.44, p = 0.204). Compared with the control group, FICB significantly decreased the occurrence of nausea (RR = 0.41, 95 % CI: 0.25 to 0.69, p = 0.010; I2 = 0.0 %). There was no significant difference in the risk of falls between the FICB and control groups (p > 0.05). The authors concluded that FICB had a beneficial role in reducing pain intensity and morphine consumption after THA. Moreover, FICB had morphine-sparing effects when compared with a control group.

Diakomi et al (2020) stated that chronic post-surgical pain (CPSP), i.e., pain persisting greater than 3 months, may appear after any type of surgery. There is a paucity of literature addressing CPSP development after hip fracture repair and the impact of any analgesic intervention on the development of CPSP in patients after hip fracture surgery. In a prospective. randomized study, these researchers examined the impact of ultrasound-guided FICB (USG-FICB) on the development of CPSP after hip fracture repair. A total of 182 patients scheduled for hip fracture surgery were included in this trial. Patients were randomized to receive a USG-FICB (FICB group) or a sham saline injection (sham FICB group), 20 mins before positioning for spinal anesthesia. The hip-related characteristic pain intensity (CPI) at 3-months post-surgery was the primary outcome measure. Presence and severity of hip-related pain at 3- and 6-months post-surgery, NRS scores at 6, 24, 36, 48 post-operative hours, total 24-hour tramadol patient-controlled analgesia (PCA) administration and timing of the first tramadol dose, were documented as well. FICB group presented with lower CPI scores 3-months post-operatively (p < 0.01), as well as lower percentage of patients with high-grade CPSP, 3 and 6 months post-operatively (p < 0.001). FICB group also showed significantly lower NRS scores in all instances, lower total 24-hour tramadol consumption and higher mean time to first tramadol dose (p < 0.05). The overall sample of 182 patients reported a considerably high incidence of hip-related CPSP (60 % at 3 months, 45 % at 6 months). The authors concluded that USG-FICB in the peri-operative setting may reduce the incidence, intensity and severity of CPSP at 3 and 6 months after hip fracture surgery, providing safe and effective post-operative analgesia.

Furthermore, an UpToDate review on "Lower extremity nerve blocks: Techniques" (Jeng and Rosenblatt, 2020) states that "Peripheral nerve blocks of the lower extremity are used for operative anesthesia and/or postoperative analgesia for a variety of lower extremity surgeries … Femoral nerve block is used to provide anesthesia or postoperative analgesia for surgery of the anterior thigh and knee (e.g., anterior cruciate ligament repair, patella surgery, quadriceps tendon repair) … The fascia iliaca block is an alternative to the femoral nerve block and may more reliably block the lateral femoral cutaneous nerve than the femoral block. It blocks the sensory innervation of the lateral thigh. This block does not depend on deposition of local anesthetic (LA) near an individual nerve; instead, it works by spread of the LA in a fascial plane. Therefore, this block is not performed with nerve stimulation. It can be done using ultrasound guidance or with an anatomic approach".

Shakya et al (2018) noted that the post-operative pain management in the elderly is challenging due to co-morbidities and change in physiology due to age itself. This limits the use of medication including pain medication. The fascia iliaca compartment block has been described in the literature for fracture of femur. It has also been safely used by non-anesthesiologist. These investigators did not find any case report of continuous fascia iliaca compartment block published in Nepal. This was their 1st experience of successful continuous fascia iliaca compartment block in the case of a 89-year old woman with multiple co-morbidities in whom traditional pain medication might be difficult to use. The authors encouraged the practice of continuous fascia iliaca compartment block, which is both safe and easy to carry out with good results.

Gopal and Krishnamurthy (2018) stated that positioning fracture femur cases for sub-arachnoid block (SAB) is challenging. Fascia iliaca compartment block (FICB) is low-skilled, helps positioning, and provides analgesia.; and dexmedetomidine (DEX) as an adjuvant prolongs analgesia. In a prospective, randomized, double-blind study, these researchers compared FICB with bupivacaine and bupivacaine with DEX in fracture femur cases with regard to positioning during SAB, duration of analgesia in terms of visual analog scale (VAS), numerical rating scale (NRS), and Patient Satisfaction Score, and evaluated side effects. A total of 60 fracture femur patients were divided into 2 groups -- Group A: FICB with injection bupivacaine 0.25 % 38 cc + DEX 0.5 μg/kg in 2 cc normal saline (NS) and Group B: FICB with injection bupivacaine 0.25 % 38 cc + 2 cc NS. Data were analyzed using SPSS 22.0 software. Categorical data were processed by frequencies and proportions, whereas continuous data were processed by mean standard deviation (MSD). Chi-square test and independent t-test were used as tests of significance, considering p < 0.05 as statistically significant. In Group A, mean VAS score at 5 mins was 3.7 ± 0.9; and in Group B it was 4.3 ± 0.7. Similarly, at 15 mins, mean VAS score in Group A was 0.4 ± 0.6 and in Group B it was 1.9 ± 0.9. VAS score was significantly high in Group B at 5, 10, and 15 mins. Mean time to rescue analgesia in Group A was 838.3 ± 82.7 mins and in Group B it was 461.5 ± 36.6 mins, which was significant. The authors concluded that FICB ensured patient comfort during positioning for SAB and provided post-operative analgesia; and DEX significantly prolonged post-operative analgesia.

The authors stated that the block success with this “feel” technique was sporadic because false “pops” could occur. Ultrasound (US)-guided technique was essentially the same; however, monitoring of the needle placement and local anesthetic delivery ensured deposition of the local anesthetic into the correct plane.

Femoral Nerve Block for Post-Operative Knee Pain

An UpToDate review on "Lower extremity nerve blocks: Techniques" (Jeng and Rosenblatt, 2019a) states that "Femoral nerve block is used to provide anesthesia or postoperative analgesia for surgery of the anterior thigh and knee (e.g., anterior cruciate ligament repair, patella surgery, quadriceps tendon repair). Traditionally, this block was also referred to as the "3-in-1" block, wherein high volume of local anesthetic (LA) can block the femoral, lateral femoral cutaneous, and obturator nerves. This concept was based on the purported existence of a supra-inguinal fluid compartment between the femoral nerve sheath and the lumbar plexus, capable of allowing spread of LA proximally to the lumbar plexus with a single injection at the femoral nerve in the inguinal region. However, a human cadaver study has shown that a fluid compartment between the femoral nerve sheath and the lumbar plexus does not exist, and several studies have shown that a femoral block does not reliably block the obturator nerve, the lateral femoral cutaneous nerve, or the lumbar plexus. Since only the femoral nerve is reliably blocked by this technique, we usually now refer to it as the femoral nerve block. Ultrasound-guided femoral block – The ultrasound transducer is placed in the inguinal crease to locate the hyperechoic femoral nerve, which can be visualized lateral to the hypoechoic pulsatile common femoral artery, superficial to the iliopsoas muscle group, and deep to the fascia lata and fascia iliaca. An in-plane or out-of-plane approach can be used. The needle is inserted and the tip placed adjacent to the nerve. After negative aspiration, 20 to 40 mL of LA is injected in 5 mL increments, with gentle aspiration between injections. LA should be seen spreading above, below, or circumferentially around the nerve".

Ilioinguinal Nerve Block

Wang et al (2016) stated that ultrasound (US)-guided ilioinguinal / iliohypogastric (II/IH) nerve and TAP blocks have been increasingly utilized in patients for peri-operative analgesia. These researchers conducted a meta-analysis to examine the clinical efficacy of US-guided II/IH nerve or TAP blocks for peri-operative analgesia in patients undergoing open inguinal surgery. A systematic search was conducted of 7 databases from the inception to March 5, 2015. Randomized controlled trials (RCTs) comparing the clinical efficacy of US-guided versus landmark-based techniques to perform II/IH nerve and TAP blocks in patients with open inguinal surgery were included. They constructed random effects models to pool the standardized mean difference (SMD) for continuous outcomes and the odds ratio (OR) for dichotomized outcomes. US-guided II/IH nerve or TAP blocks were associated with a reduced use of intra-operative additional analgesia and a significant reduction of pain scores during day-stay. The use of rescue drugs was also significantly lower in the US-guided group. The authors concluded that the use of US-guidance to perform an II/IH nerve or a TAP block was associated with improved peri-operative analgesia in patients following open inguinal surgery compared to landmark-based methods.

In a prospective, randomized clinical trial, Faiz et al (2019) compared the efficacy of ilioinguinal / iliohypogastric (IINB) nerve block to TAP block in controlling incisional pain after open inguinal hernia repair. This trial included 90 patients who received either IINB (n = 45) or TAP block (n = 45) using 0.2 % bupivacaine 15 ml under US guidance based on a random assignment in the post-anesthesia care unit (PACU) after having an open repair of inguinal hernia. Numeric Rating Scale (NRS) scores were recorded immediately following, 4, 8, 12, and 24 hours after completion of the block; NRS scores at rest and during movement were recorded 24, 36, and 48 hours after surgery. Analgesic satisfaction level was also evaluated by a Likert-based patient questionnaire. NRS scores were lower in the IINB group compared to the TAP block group both at rest and during movement. The difference in dynamic pain scores was statistically significant (p = 0.017). In addition, analgesic satisfaction was significantly greater in the IINB group than the TAP block group (mean score 2.43 versus 1.84, p = 0.001). Post-operative opioid requirements did not differ between the 2 groups. The authors concluded that the findings of this study demonstrated that compared to TAP block, local blockade of ilioinguinal and iliohypogastric nerves provided better pain control after open repair of inguinal hernia when both blocks were administered under US guidance. Greater satisfaction scores also reflected superior analgesia in patients receiving IINB.

Bhatia et al (2019) noted that analgesic efficacy of US-guided TAP block, administered a little more medially, just close to the origin of the transverse abdominis muscle has not yet been examined in patients undergoing unilateral inguinal hernia repair. These researchers hypothesized that medial TAP block would provide comparable post-operative analgesia to ilioinguinal-iliohypogastric nerve block in inguinal hernia repair patients. This prospective, randomized trial was conducted in 50 ASA I and II male patients greater than or equal to 18 years of age. Patients were randomized into 2 groups to receive either pre-incisional ipsilateral US-guided ilioinguinal-iliohypogastric nerve block or medial TAP block, with 0.3 ml/kg of 0.25 % bupivacaine. The primary objective was post-operative 24-hour analgesic consumption and secondary outcomes included pain scores, time to first request for rescue analgesic and side effects, if any, in the post-operative period. There was no significant difference in the total post-operative analgesic consumption [group I: 66.04 mg; group II: 68.33 mg (p value 0.908)]. Time to first request for rescue analgesic was delayed, though statistically non-significant (p value 0.326), following medial TAP block, with excellent pain relief observed in 58.3 % patients as opposed to 45.8 % patients in ilioinguinal-iliohypogastric nerve block group. The authors concluded that medial TAP block being a novel, simple and easily performed procedure can serve as an useful alternative to ilioinguinal-iliohypogastric nerve block for providing post-operative pain relief in inguinal hernia repair patients.

Samerchua et al (2020) stated that ilioinguinal/iliohypogastric nerve block is commonly performed to control post-herniotomy pain. The posterior quadratus lumborum block has been recently described as an effective analgesic technique for pediatric low abdominal surgery. No data were found regarding the use of posterior quadratus lumborum block in comparison with the traditional ilioinguinal/iliohypogastric nerve block in pediatric inguinal surgery. In a randomized, assessor-blinded study, these researchers compared post-operative analgesic effects between US-guided posterior quadratus lumborum block and ilioinguinal/iliohypogastric nerve block in pediatric inguinal herniotomy. 1- to 7-year-old children scheduled for unilateral open herniotomy were randomly assigned to receive either US-guided posterior quadratus lumborum block with 0.25 % bupivacaine 0.5 ml/kg or US-guided ilioinguinal/iliohypogastric nerve block with 0.25 % bupivacaine 0.2 ml/kg after induction of general anesthesia. The primary outcome was the proportion of patients who received post-operative oral acetaminophen. The required fentanyl in the recovery room, 24-hour acetaminophen consumption, success rate of regional blocks, block performance data, block-related complications, post-operative pain intensity, and parental satisfaction were assessed. This study included 40 patients after excluding 4 cases who were ineligible. The number of patients who required post-operative oral acetaminophen was significantly lower in the posterior quadratus lumborum block group (15.8 % versus 52.6 %; odds ratio [OR]: 5.9; 95 % confidence interval [CI]: 1.3 to 27.3; p = 0.022). The pain scores at 30 mins, 1, 2, 6, 12, and 24 hours were similar between groups. There was no evidence of between-group differences in block performance time, the number of needle passes, block-related complications, and parental satisfaction. The authors concluded that the posterior quadratus lumborum block with 0.25 % bupivacaine 0.5 ml/kg provided better pain control than the ilioinguinal/iliohypogastric nerve block with 0.25 % bupivacaine 0.2 ml/kg after open herniotomy in children. The US guidance technique for the posterior quadratus lumborum block was safe and as simple as the US-guided ilioinguinal/iliohypogastric nerve block for pediatric patients.

Intercostobrachial Nerve Block

Satapathy and Coventry (2011) noted that the axillary approach to brachial plexus blockade provides satisfactory anesthesia for elbow, forearm, and hand surgery and also provides reliable cutaneous anesthesia of the inner upper arm including the medial cutaneous nerve of arm and intercostobrachial nerve, areas often missed with other approaches. In addition, the axillary approach remains the safest of the 4 main options, as it does not risk blockade of the phrenic nerve, nor does it have the potential to cause pneumothorax, making it an ideal option for day case surgery. Historically, single-injection techniques have not provided reliable blockade in the musculocutaneous and radial nerve territories, but success rates have greatly improved with multiple-injection techniques whether using nerve stimulation or US guidance. Complete, reliable, rapid, and safe blockade of the arm is now achievable. The authors concluded that axillary nerve block is a safe and effective regional anesthetic technique suitable for a wide variety of procedures, for both in-patient and out-patient care]; US guidance has allowed improved efficacy with smaller volumes of local anesthetic. Direct visualization of block performance and local anesthetic injection, though inherently safer, does not completely eliminate the risk of intra-vascular and intra-neural injection, and care should be continually exercised using standard safety precautions of slow, careful, fractionated injections to prevent and minimize the risks associated with the technique.

Thallaj et al (2015) tested the hypothesis that identification and blockade of the intercostobrachial nerve (ICBN) can be achieved under US guidance using a small volume of local anesthetic. A total of 28 adult male volunteers were examined at King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia from November 2012 to September 2013. Intercostobrachial nerve blockade was performed using 1-ml of 2 % lidocaine under US guidance. A sensory map of the blocked area was developed relative to the medial aspect of the humeral head. The ICBN appeared as a hyper-echoic structure. The nerve diameter was 2.3 ± 0.28 mm, and the depth was 9 ± 0.28 mm. The measurements of the sensory-blocked area relative to the medial aspect of the humeral head were as follows: 6.3 ± 1.6 cm anteriorly; 6.2 ± 2.9 cm posteriorly; 9.4 ± 2.9 cm proximally; and 9.2 ± 4.4 cm distally. Intercostobrachial nerve blockade using 1-ml of local anesthetic was successful in all cases. The authors concluded that this study described the sonographic anatomical details of the ICBN and its sensory distribution to successfully perform selective US-guided ICBN blockade. These researchers stated that this technique can be used as a supplemental block for upper limb anesthesia. They recommended further studies to support and apply these findings to improve patient care.

Wijayasinghe et al (2016) stated that persistent pain after breast cancer surgery (PPBCS) affects 25 to 60 % of breast cancer survivors and damage to the ICBN has been implicated as the cause of this predominantly neuropathic pain. Local anesthetic blockade of the ICBN could provide clues to pathophysiological mechanisms as well as aiding diagnosis and treatment of PPBCS but has never been attempted. In a prospective, pilot study, these researchers examined the feasibility of ICBN blockade and evaluated its effects on pain and sensory function in patients with PPBCS. This trial was performed in 2 parts: Part 1 determined the sonoanatomy of the ICBN and part 2 examined the effects of the US-guided ICBN blockade in patients with PPBCS. Part 1: 16 unoperated, pain-free BC patients underwent systematic ultrasonography to establish the sonoanatomy of the ICBN. Part 2: 6 patients with PPBCS who had pain in the axilla and upper arm were recruited for the study. Summed pain intensity (SPI) scores and sensory function were measured before and 30 mins after the block was administered. SPI is a combined pain score of numerical rating scale (NRS) at rest, movement, and 100 kPa pressure applied to the maximum point of pain using pressure algometry (max = 30). Sensory function was measured using quantitative sensory testing (QST), which consisted of sensory mapping, thermal thresholds, supra-threshold heat pain perception as well as heat and pressure pain thresholds. The ICBN block was performed under US-guidance and 10 ml 0.5 % bupivacaine was injected. Outcome measures included the ability to perform the ICBN block and its analgesic and sensory effects. Only the second intercostal space could be observed on US, which was adequate to perform the ICBN block. The mean difference in SPI was -9 NRS points (95 % confidence interval [CI]: -14.1 to -3.9; p = 0.006). All patients had pre-existing areas of hypoesthesia that decreased in size in 4/6 patients following the block. The authors successfully blocked the ICBN using US-guidance and demonstrated an analgesic effect in patients in PPBCS calling for placebo-controlled studies. The main drawback of this pilot study was its small sample size (n = 6), but despite this, a statistically significant effect was observed. These researchers stated that the premise of this study was to examine the feasibility of a randomized controlled trial (RCT) and these findings suggested that a RCT is needed to determine the role of ICBN blockade in PPBCS.

Magazzeni et al (2018) stated that for superficial surgery of antero-medial and postero-medial surfaces of the upper arm, the medial brachial cutaneous nerve (MBCN) and the ICBN must be selectively blocked, in addition to an axillary brachial plexus block. Ina randomized study, these researchers compared efficacy of US-guided (USG) versus conventional block of the MBCN and the ICBN. A total of 84 patients, undergoing upper limb surgery, were randomized to receive either USG (n = 42) or conventional (n = 42) block of the MBCN and the ICBN with 1 % mepivacaine. Sensory block was evaluated using light-touch on the upper and lower half of the antero-medial and postero-medial surfaces of the upper arm at 5, 10, 15, 20 mins after nerve blocks. The primary outcome was the proportion of patients who had no sensation in all 4 regions innervated by the MBCN and the ICBN at 20 mins. Secondary outcomes were onset time of complete anesthesia, volume of local anesthetic, tourniquet tolerance, and quality of US images. In the USG group, 37 patients (88 %) had no sensation at 20 mins in any of the 4 areas tested versus 8 patients (19 %) in the conventional group (p < 0.001). When complete anesthesia was obtained, it occurred within 10 mins in more than 90 % of patients, in both groups. Mean total volumes of local anesthetic used for blocking the MBCN and the ICBN were similar in the 2 groups; US images were of good quality in only 20 (47.6 %) of 42 patients; 41 patients (97.6 %) who received USG block were comfortable with the tourniquet versus 16 patients (38.1 %) in the conventional group (p < 0.001). The authors concluded that US guidance improved the efficacy of the MBCN and ICBN blocks.

Inter-Digital Neuroma Injection

Morgan et al (2014) stated that Morton's neuroma (MN) is a frequently painful condition of the forefoot, causing patients to seek medical care to alleviate symptoms. A plethora of therapeutic options is available, some of which include injection therapies. Researchers have examined injection therapy for MN, and the evidence base has been augmented with methods that use diagnostic US as a vehicle to deliver the injectate under image guidance for additional accuracy. To-date, there appeared to be no consensus that US-guided injections provided better therapeutic outcomes than non-guided injections for the treatment of MN. In a systematic review, these researchers identified 13 key studies using pre-determined inclusion and exclusion criteria, which then underwent methodological quality assessment using a pre-tested Quality Index. A narrative synthesis of the review findings was presented in light of the heterogeneity of the data from the extraction process. This systematic review provided an argument that US guidance could produce better short- and long-term pain relief for corticosteroid injections, could reduce the need for additional procedures in a series of sclerosing alcohol injections, could reduce the surgical referral rate, and could add efficacy to a single injection. The authors concluded that US guidance should be considered for injection therapy in the management of MN.

In a randomized, evaluator-blinded study, Santiago et al (2019) compared the effectiveness of blind and US-guided injection for Morton's neuroma (MN) to determine which is more appropriate as the initial procedure in conservative treatment. Of the 56 included patients, 27 were assigned to the blind group (A) and 29 to the US-guided group (B). Injection includes 1-ml of 2 % mepivacaine and 40-mg of triamcinolone in each web space with MN. The included patients were examined clinically by VAS score and the Manchester Foot Pain and Disability Score (MFPDS). The follow-up was carried out at 15 days, 1 month, 45 days, 2 months, 3 months, and 6 months after the initial injection. No differences in age or clinical measurements were found at presentation between group A and group B. At the follow-up, the US-guided group showed greater symptomatic relief at several stages of the follow-up: 45 days (VAS 3.0 ± 0.5 versus 5.5 ± 0.5, p = 0.001; MFPDS: 32.2 ± 1.8 versus 38.8 ± 2.0, p = 0.018), 2 months (VAS: 3.1 ± 0.5 versus 5.6 ± 0.5, p = 0.002; MFPDS: 31.5 ± 1.9 versus 38.5 ± 2.1, p = 0.020) and 3 months (VAS: 3.1 ± 0.4 versus 5.2 ± 0.6, p = 0.010; MFPDS: 31.2 ± 1.9 versus 37.7 ± 2.4, p = 0.047). The authors concluded that injection of MN under US guidance provided a statistically significant improvement at some stages of the follow-up (45 days, 2 and 3 months), compared with blind injection. However, there were no significant differences between guided and non-guided injections at other time-points (15 days, 1 month, and 6 months).

In a prospective, follow-up study of a previous RCT, Hay et al (2021) examined the medium-term results of corticosteroid injections for MN. A total of 45 MNs in 36 patients were injected with a single corticosteroid injection either with or without US guidance. As the results of the RCT showed no difference in outcomes between techniques, the data were pooled for this study. Questionnaires were sent out and responses were collected via mail or telephone interview. Results were available in 42 out of 45 MNs. There was a sex split of 68 % female/32 % male with a mean age of 62.6 years (SD, 12 years). At mean follow-up of 4.8 years (SD, 0.91 years), the original corticosteroid injection remained effective in 36 % (n = 16) of the patients. In these cases, the VAS pain score (p < 0.001) and Manchester-Oxford Foot Questionnaire Index (MOxFQ Index) (p = 0.001) remained significantly better than pre-intervention scores. The remaining cases underwent either a further injection or surgery; 55 % of the 11 MNs that received a 2nd injection continued to be asymptomatic in the medium-term. A total of 44 % (n = 20) of the initial cohort underwent surgical excision by the medium-term follow-up. The VAS score, MOxFQ Index, and satisfaction scale score across all groups were not significantly different. The authors concluded that corticosteroid injections for MN remained effective in over a 1/3 of cases for up to almost 5 years. A positive outcome at 1 year following a corticosteroid injection was reasonably predictive of a prolonged effect from the injection.

In a systematic review, Choi et al (2021) examined the effects of corticosteroid injections on MN using an algorithmic approach to evaluate the methodological quality of reported studies using a structured critical framework. Several electronic databases were searched for articles published until April 2020 that examined the outcomes of corticosteroid injections in patients diagnosed with MN. Data search, extraction, analysis, and quality assessments were carried out according to the PRISMA guidelines, and clinical outcomes were evaluated using various outcome measures. With 3 to 12 months of follow-up, corticosteroid injections provided satisfactory outcomes according to Johnson satisfaction scores except in 2 studies; VAS scores showed maximal pain reduction between 1 week and 3 months after injection. These researchers found that 140 subjects out of 469 (29.85 %) eventually underwent surgery after receiving corticosteroid injections due to persistent pain. The authors concluded that corticosteroid injections showed a satisfactory clinical outcome in patients with Morton's inter-digital neuroma although almost 30 % of the included subjects eventually underwent operative treatment. Their recommendation for future research included using more objective outcome parameters, such as foot and ankle outcome scores or foot and ankle ability measures. Moreover, studies on the safety and effectiveness of multiple injections at the same site are highly necessary.

These researchers also noted that in their review, injections carried out under US guidance were reported in 5 studies, while blind injections were carried out in 4 articles. They also found 2 RCTs comparing US-guided injections with blind injections. However, these investigators thought a meta-analysis of these studies was impossible as the characteristics of the selected studies were totally heterogeneous with regard to the injected agent, outcome parameters, outcome measurement timing, number of injections, and follow-up period. With current data, the authors recommended the use of US depending on the surgeon's experience and confidence; US guidance may not be necessary if the surgeon can ensure solid and constant results with blind injection.

Klontzas et al (2021) stated that MN is a painful lesion of the interdigital nerve, usually at the 3ird intermetatarsal space, associated with fibrotic changes in the nerve, microvascular degeneration, and deregulation of sympathetic innervation. Patients usually present with burning or sharp metatarsalgia at the dorsal or plantar aspect of the foot. The management of MN starts with conservative measures, usually with limited efficacy, including orthotics and anti-inflammatory medication. When conservative treatment fails, a series of minimally invasive US-guided procedures can be used as 2nd-line treatments prior to surgery. Such procedures include infiltration of the area with a corticosteroid and local anesthetic, chemical neurolysis with alcohol or radiofrequency (RF) thermal neurolysis. Ultrasound aids in the accurate diagnosis of MN and guides the afore-mentioned treatment, so that significant and potentially long-lasting pain reduction can be achieved. In cases of initial treatment failure, the procedure can be repeated, usually leading to the complete remission of symptoms. The authors concluded that US is the imaging modality of choice for the diagnosis of MN, while also enabling imaging-guided treatment. US-guided procedures including corticosteroid infiltration, chemical neurolysis and RF thermal neurolysis are viable alternatives to surgical treatment, offering high rates of complete remission of symptoms in patients when conservative management has failed, prior to surgery.

Sconfienza et al (2021) stated that clarity regarding accuracy and effectiveness for interventional procedures around the foot and ankle is lacking. Consequently, a board of 53 members of the Ultrasound and Interventional Subcommittees of the European Society of Musculoskeletal Radiology (ESSR) reviewed the published literature to examine the evidence on image-guided musculoskeletal interventional procedures around this anatomical region. These investigators reported the findings of a Delphi-based consensus of 53 experts from the ESSR who reviewed the published literature for evidence on image-guided interventional procedures offered around foot and ankle in order to derive their clinical indications. Experts drafted a list of statements and graded them according to the Oxford Centre for evidence-based medicine levels of evidence. Consensus was considered strong when greater than 95 % of experts agreed with the statement or broad when greater than 80 % but less than 95 % agreed. The results of the Delphi-based consensus were used to draft the paper that was shared with all panel members for final approval. A list of 16 evidence-based statements on clinical indications for image-guided musculoskeletal interventional procedures in the foot and ankle were drafted after a literature review. The highest level of evidence was reported for 4 statements, all receiving 100 % agreement. The authors concluded that according to this consensus, image-guided interventions should not be considered a 1st-level approach for treating Achilles tendinopathy, while US guidance is strongly recommended to improve the efficacy of interventional procedures for plantar fasciitis and MN, particularly using platelet-rich plasma and corticosteroids, respectively.

Interscalene Nerve Block

Rajpal et al (2016) noted that post-operative neurologic symptoms after interscalene block and shoulder surgery have been reported to be relatively frequent. These investigators evaluated 300 patients for neurologic symptoms after low-volume, US-guided interscalene block and arthroscopic shoulder surgery (ASS). Patients underwent US-guided interscalene block with 16 to 20 ml of 0.5 % bupivacaine or a mix of 0.2 % bupivacaine/1.2 % mepivacaine solution, followed by propofol/ketamine sedation for ambulatory ASS. Patients were called at 10 days for evaluation of neurologic symptoms, and those with persistent symptoms were called again at 30 days, at which point neurologic evaluation was initiated. Details of patient demographics and block characteristics were collected to assess any association with persistent neurologic symptoms; 6 of 300 patients reported symptoms at 10 days (2 %), with 1 of these patients having persistent symptoms at 30 days (0.3 %). This was significantly lower than rates of neurologic symptoms reported in pre-US investigations with focused neurologic follow-up and similar to other studies performed in the US era. There was a modest correlation between the number of needle re-directions during the block procedure and the presence of post-operative neurologic symptoms. The authors concluded that US guidance of interscalene block with 16- to 20-ml volumes of local anesthetic solution resulted in a lower frequency of post-operative neurologic symptoms at 10 and 30 days as compared with investigations in the pre-US period.

Fuzier et al (2016) performed a cross-sectional survey study on French practice in US-guided regional anesthesia. A questionnaire (demographic data, assessment of the likely benefits of US, and its use in daily practice: blocks and hygiene) was emailed to all members of the French-speaking association of anesthesiologists involved in regional anesthesia. The questionnaire was filled out and returned by 634 experienced anesthesiologists. An US machine was available in 94 % of cases; US-guided regional anesthesia has become the gold standard technique for 3/4 of responders. Interscalene, popliteal sciatic and femoral nerve blocks were performed by more than 90 % of responders, most frequently under US supervision. Conversely, US guidance was rarely used for spinal or deep nerve blocks. A specific sterile sheath was used in only 43 % of cases. The authors concluded that the present study confirmed that US guidance has gained in popularity for many superficial, but not deep, regional anesthesia procedures in France.

Kolny et al (2017) stated that interscalene brachial plexus block (ISBPB) is an effective regional anesthesia technique for shoulder surgeries. The superiority of the popular US-guided blocks over peripheral nerve stimulator (PNS)-confirmed blocks remains unclear. In this study, the efficacy of these different block techniques was compared. This prospective, randomized, clinical study included 109 patients (American Society of Anesthesiologists [ASA] grades I-III) who receive 20 ml 0.5 % ropivacaine with US-guided blocks (U group), PNS-confirmed blocks (N group), or US-guided and PNS-confirmed blocks (dual guidance; NU group) for elective shoulder arthroscopy. Block onset time, duration, and effectiveness on the Lovett rating scale (LRS) were assessed. There was no statistically significant inter-group difference in duration of block performance, irrespective of the technique (p = 0.232). Onset time of complete warmth sensation loss (p < 0.001) and muscle strength abolition (p < 0.001) was significantly longer and mean LRS score distribution was significantly higher in the N group than in the other groups (p < 0.001). These findings showed a statistically significant correlation between the performance of the used block technique and the necessity of conversion to general anesthesia because of insufficient block in the N group (58.54 %) than in the U (24.44 %) and NU (19.57 %) groups. The authors stated that in a majority of studies, US guidance tended to be superior to PNS assistance for ISBPB. Compared to PNS assistance, US guidance led to faster onset time of ISBPB, lowered the rate of conversions to general anesthesia, and improved LRS scores. They concluded that PNS-confirmed needle placement was not necessary to ensure effectiveness of US-guided blocks as evidenced by the low rate of conversion to general anesthesia in this study. Nevertheless, the dual guidance technique (US guidance and PNS confirmation) was recommended to reduce the risk of complications and might be considered the regional anesthesia of choice for shoulder surgery.

In a RCT, Woo et al (2018) examined if ISBPB using a lower concentration of local anesthetic would reduce the incidence of post-thoracotomy ipsilateral shoulder pain with assessment of pulmonary function in patients who underwent a lung lobectomy. A total of 44 patients who underwent a lung lobectomy were randomly assigned to either the control or the interscalene block (ISB) group. Single-shot ISB on the surgical site side was performed using ropivacaine 10-ml 0.25 % including 5-mg dexamethasone under US guidance in the ISB group. Lobectomy and continuous paravertebral block were performed under general anesthesia. The presence of ipsilateral shoulder pain and post-operative adverse events (AEs) were assessed. Pulmonary function tests were performed pre-operatively, the day after surgery, and the day after removing the chest tube. The incidence of ipsilateral shoulder pain was significantly lower in the ISB group than in the control group (54.5 % versus 14.3 %, p = 0.006) with an overall incidence of 34.9 %. Post-operative AEs were similar between the groups, with no patients presenting symptoms of respiratory difficulty. Significant reductions in pulmonary function were observed in all patients after lobectomy; however, no significant difference in any of the pulmonary function test variables was observed post-operatively between the groups. The authors concluded that ISB using 10-ml of 0.25 % ropivacaine including 5-mg dexamethasone reduced the incidence of post-thoracotomy ipsilateral shoulder pain and did not result in additional impairment of pulmonary function.

In a prospective, randomized, clinical study, Stasiowski et al (2018a) evaluated the effect of the ISBPB on the occurrence rate of Horner's syndrome. A total of 108 randomly selected patients of ASA I-III status were scheduled for elective shoulder arthroscopy. The patients received 20 ml of 0.5 % ropivacaine either with US-guided ISBPB (U), PNS-confirmation ISBPB (N), or US-guided, PNS-confirmed ISBPB (dual guidance; NU). These researchers observed that Horner's syndrome developed in 12 % of the N group, 6 % of the NU group, and 9 % of the U group. The differences in the rates were not statistically significant (p = 0.616). Regardless of the technique used to induce ISBPB, this study did not demonstrate any particular anthropometric parameter that pre-disposed patients to the development of Horner's syndrome. Interestingly, these findings showed that NU patients with Horner's syndrome were significantly younger than NU patients without Horner's syndrome. The authors concluded that the precision of ISBPB by use of the dual guidance technique may reduce the rate of Horner's syndrome. The higher water concentration in the prevertebral spaces of younger patients may create better conditions for the diffusion of ropivacaine, which may result in a statistically significant higher Horner's syndrome rate.

In a prospective, randomized, clinical study, Stasiowski et al (2018b) examined the influence of anthropometric parameters and ISBPB on the quality of post-operational analgesia. A total of 109 randomly selected patients of ASA I-III status were scheduled for elective shoulder arthroscopy. Reasons for non-inclusion were as follows: neurological deficit in the upper arm; allergies to amide Las; coagulopathy; and pregnancy. Patients were divided into 3 groups – group U, group N, or group NU. These researchers observed that the studied groups did not differ in mean time of sensory and motor block terminations and, surprisingly, in each group in individual cases the sensory block lasted up to 890 to 990 mins providing satisfactory long-lasting post-operational analgesia in patients receiving ISBPB. These investigators observed a negative correlation between body mass index (BMI) and termination of the motor block and a positive correlation between age and termination of the sensory block in group U in comparison with the 2 other groups. They found a positive correlation between the male gender and termination of the motor block in patients in group N in comparison with 2 other groups. The authors concluded that in this study, patients received satisfactory analgesia in the post-operational period no matter what technique was used regardless of their age, gender or potentially uncommon anthropometry.

Long Head of the Biceps Injection for the Treatment of Tendinosis of the Biceps

In a prospective, single-blinded, pilot study, Gazzillo et al (2011) examined the accuracy of palpating the long head of the biceps tendon (LHBT) within the inter-tubercular groove with the use of ultrasonographic (US) localization as a gold standard. A total of 25 male and female asymptomatic volunteers aged 24 to 41 years (mean of 30.9 ± 4.3 years) with body mass indices (BMI) of 19.3 to 36.3 kg/m(2) (23.84 ± 4.8 kg/m(2)) were included in this study. Three examiners of differing experience (a sports medicine board-certified staff physician, a sports medicine fellow, and a physical medicine and rehabilitation resident) identified the LHBT location in the inter-tubercular groove via palpation on a subject in the supine position and marked its location by taping an 18-G Tuohy needle to the skin overlying the groove. The examiner order was randomized. A 4th examiner who was blinded to the palpation order assessed the previous examiner's palpation accuracy by comparing the needle position to the US-determined tendon position. Needle placement in relation to the inter-tubercular groove was graded as being within the groove, medial to the groove, or lateral to the groove. In the latter 2 cases, the distance from the needle to the closest groove edge was recorded. Overall accuracy rate was 5.3 % (4/75), ranging from 0 % (0/25) for the resident to 12 % (3/25) for the fellow (p ≤ 0.007 for inter-examiner differences). All missed palpations were localized medial to the inter-tubercular groove by an average of 1.4 ± 0.5 cm (range of 0.3 for the fellow to 3.5 cm for the resident). The authors concluded that based on the current methodology, clinicians have a tendency to localize the inter-tubercular groove medial to its actual location. Consequently, clinicians should exercise caution when relying on clinical palpation to either diagnose a biceps tendon disorder or perform a bicipital tendon sheath injection. When clinically indicated, US guidance can be used to accurately identify the LBHT within the inter-tubercular groove.

In a prospective randomized, comparative study, Yiannakopoulos et al (2020) compared accuracy, patient discomfort, and clinical outcome of US-guided versus palpation-guided corticosteroid injections to the bicipital groove in patients with LHB tendinosis. A total of 44 patients with primary LHB tendinosis were randomized into 2 groups (group A, n = 22; group B, n = 22). All patients underwent treatment with a single corticosteroid injection to the bicipital groove. Injections in group A were performed under US-guidance, while in group B using a palpation-guided technique. The duration of each procedure was recorded. To assess accuracy, US examination was performed in both groups after injection. Patient discomfort was evaluated with visual analog scale (VAS) for pain. The clinical outcome was assessed comparing the VAS, the Single Assessment Numeric Evaluation (SANE) score and the QuickDASH score before treatment and after 4 weeks and 6 months. The mean duration of the procedure was 64 ± 6.87 seconds in group A and 81.91 ± 8.42 seconds in group B (p < 0.001). Injection accuracy in group A was 100 % and in group B 68.18 %. Discomfort was lower in group A, as compared to group B (22.10 versus 35.50; p < 0.001). Symptoms, as measured by VAS, SANE and QuickDASH scores, improved in both groups at 4 weeks and 6 months (p < 0.05). Superior clinical improvement was recorded in group A in both time-points (p < 0.05). The authors concluded that corticosteroid injections were an effective treatment for primary LHB tendinosis. Under US guidance, injections to the bicipital groove were faster and produced lower discomfort. Superior accuracy and clinical outcomes can be achieved using the US-guided technique. Level of Evidence = II.

Furthermore, an UpToDate review on “Biceps tendinopathy and tendon rupture” (Simons and Dixon, 2021) states that “Musculoskeletal ultrasound [US] appears to have high sensitivity and specificity for identifying normal tendons and complete tears of the LHBT. Accuracy is more limited with partial tears and other tendon pathology (e.g., tendinopathy) … As the initial treatment of both LHBT tendinopathy and rupture is typically conservative, advanced diagnostic imaging plays a limited role in the initial workup. Ultrasound enables the trained clinician to evaluate tendons while they are in motion and to compare them with the contralateral shoulder at the bedside. Ultrasound has high sensitivity and specificity for complete tears of the LHBT”.

Needle Placement, Lavage, and Debridement of Calcific Tendinosis of the Shoulder

Gatt et al (2014) carried out a systematic review to examine the outcomes and complications of ultrasound (US)-guided barbotage (repeated injection and aspiration) for calcific tendonitis of the shoulder. They performed a literature search of the Medline, Embase, and Cochrane databases using all relevant keywords found 1,454 original articles. After removal of duplicates and application of inclusion criteria, 13 original articles were selected for review. Articles that used fluoroscopic guidance rather than US guidance were excluded from the review. All studies analyzed except 1 were case series, with no comparative studies being available. A total of 13 articles with a total of 908 patients were analyzed. In all articles reviewed, the authors reported a good clinical outcome, with many achieving marked improvement in clinical scores or overall satisfaction with the treatment. The authors concluded that US-guided barbotage is a safe technique, with a high success rate and low complication rate. There was no evidence assessing its effectiveness compared with other major treatment modalities; a randomized trial comparing US-guided barbotage, extracorporeal shock wave therapy (ESWT), and arthroscopic calcific deposit excision would be of great value. However, while awaiting such a trial, on the basis of the results of this systematic review, these investigators recommended US-guided barbotage.

Murray et al (2020) noted that injection of steroid and anesthetic into the greater trochanteric bursa is commonly performed for trochanteric bursitis, gluteus medius/minimus tendinopathy, or as a part of a barbotage procedure for gluteus medius or minimus calcific tendinosis. Trochanteric bursal injection is widely performed both with and without image guidance; and is typically viewed as low-difficulty; however optimum needle tip position can be challenging. The authors discussed a simple dynamic US-guided technique to aid the practitioner in optimal needle placement.

Lanza et al (2021) compared the outcome of US-guided percutaneous irrigation of calcific tendinopathy (US-PICT) of the rotator cuff in patients with or without previous external shockwave therapy. These researchers analyzed all patients treated with US-PICT from March 1, 2016, to October 1, 2019, with shoulder pain refractory to conservative management for rotator cuff calcific tendinopathy, diagnosed with US. Each patient was examined using the Constant-Murley Score (CMS) questionnaire (score 0 to 100) before and after treatment. These investigators tested CMS differences using the Mann-Whitney U (Wilcoxon rank-sum) test in the 2 groups. US-PICT was carried out placing 2 or multiple 14G needles, according to the calcification size, inserted under US guidance to create a circuit of irrigation in the calcified tendon. NaCl solution at 38 °C was then injected from the entry needle in a variable amount to hydrate and fragment the calcification, finally allowing for its expulsion through the exit needle. All patients also received an intra-bursal steroid injection. From 2016 to 2019, a total of 72 US-PICT treatments were performed on 70 patients (women = 46; men = 26) with a mean age of 49.7 years (SD = 8.7. 33 (47 %) underwent previous ESWT, while 37 (53 %) had no previous treatments. No treatment-related complications were observed. Follow-up was averagely 14.4 months (median of 11.6, SD = 11.9, range of 1 to 45); 37 patients had a follow-up shorter than 12 months (1 to 11.6); 35 patients were visited after more than 1 year (12.2 to 45.6). Before treatment, the mean CMS was 35 (SD = 21); after treatment, it reached 75.4, with an average CMS improvement of 40.3 points (SD = 23.7, p < 0.001). The comparison of improvement between the ESWT and non-ESWT group yielded no significant difference (p = 0.3). The authors concluded that US-PICT of the rotator cuff was an effective procedure to reduce shoulder pain and increase mobility in patients with calcific tendinopathy, both in short- and long-term time intervals. Previous unsuccessful ESWT does not affect the outcome of US-PICT.

Bechay et al (2020) stated that calcific tendinopathy of the shoulder involves calcification and degeneration of the rotator cuff tendon near its insertion point on the greater tuberosity. These researchers analyzed recent literature evaluating the clinical outcomes of non-operative and operative treatment for calcific tendinopathy of the shoulder. Conservative management, extracorporeal shockwave therapy (ESWT), US-guided percutaneous irrigation of calcific tendinopathy (US-PICT), and surgical intervention were reviewed.

Louwerens et al (2020) compared clinical and radiographic outcomes after treatment with standardized high-energy ESWT)and US-guided needling (UGN) in patients with symptomatic calcific tendinitis of the rotator cuff who were non-responsive to conservative treatment. The study was designed as a randomized controlled trial (RCT). The ESWT group received ESWT (2,000 pulses, energy flux density 0.35 mJ/mm2) in 4 sessions with 1-week intervals. UGN was combined with a corticosteroid US-guided subacromial bursa injection. Shoulder function was assessed at standardized follow-up intervals (6 weeks and 3, 6, and 12 months) using the Constant Murley Score (CMS), the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire, and visual analog scale (VAS) for pain and satisfaction. The size, location, and morphology of the deposits were evaluated on radiographs. The a priori sample size calculation computed that 44 participants randomized in each treatment group was needed to achieve a power of 80 %. A total of 82 patients were treated (56 women, 65 %; mean age of 52.1 ± 9 years) with a mean baseline CMS of 66.8 ± 12 and mean calcification size of 15.1 ± 4.7 mm; 1 patient was lost to follow-up. At 1-year follow-up, the UGN group showed similar results as the ESWT group with regard to the change from baseline CMS (20.9 versus 15.7; p = 0.23), DASH questionnaire (-20.1 versus -20.7; p = .78), and VAS for pain (-3.9 and -2.6; p = 0.12). The mean calcification size decreased by 13 ± 3.9 mm in the UGN group and 6.7 ± 8.2 mm in the ESWT group (p = 0.001). In total, 22% of the UGN and 41 % of the ESWT patients received an additional treatment during follow-up because of persistent symptoms. The authors conclude d that this RCT compared the clinical and radiographic results of UGN and high-energy ESWT in the treatment of calcific tendinitis of the rotator cuff. Both techniques were successful in improving function and pain, with high satisfaction rates after 1-year follow-up; however, UGN was more effective in eliminating the calcific deposit, and the amounts of additional treatments was greater in the ESWT group. Level of evidence = II.

Vassalou et al (2021) identified prognostic factors affecting the clinical outcome in patients treated with rotator cuff US-PICT by evaluating the degree of calcium removal, the size and consistency of calcific deposits, and baseline level of shoulder pain and functionality. From January 2017 to December 2019, a total of 79 patients (23 men, 56 women; mean age of 45.7 years) who underwent US-PICT were prospectively enrolled. The calcifications' location, consistency, and size were evaluated. For US-PICT, local anesthesia, lavage of calcific material, and intra-bursal steroid injection were performed. The degree of calcium removal was graded as total/partial. Shoulder pain and functionality were assessed with the visual analog scale (VAS) in all and Constant score (CS) in a subset of patients, respectively, at 4 time-points. Mann-Whitney U test, Fisher's test, and linear and binary logistic regression were utilized for analysis. Pain improvement correlated with the presence of larger calcifications and lower baseline VAS score, at 1 week (p = 0.001, p < 0.001, respectively) and 1 year (p < 0.001, p = 0.002, respectively). Improved functionality correlated with total calcification retrieval, higher baseline CS, and fluid/soft calcific consistency at 1 week (p = 0.013, p = 0.003, p = 0.019, respectively). Increased calcification size, cystic appearance, and lower baseline VAS scores independently predicted complete pain resolution at 1 year. The authors concluded that large calcifications and low-grade pain at baseline correlated with short- and long-term pain improvement. The degree of calcium removal did not impact pain or functional improvement beyond 1 week. Increased calcification size, cystic appearance, and low-grade baseline pain predicted complete pain recovery at 1 year.

Key points:

The presence of larger calcifications and lower-grade baseline pain appeared to correlate with pain improvement at 1 week and 1 year after US-guided irrigation of rotator cuff calcific tendinopathy (US-PICT).
Total calcification retrieval, less affected baseline shoulder functionality, and presence of fluid/soft consistency of calcific deposits appeared to correlate with improved shoulder functionality at 1-week post-treatment.
Baseline pain intensity and calcifications' morphologic characteristics, but not the degree of calcium retrieval, represent predictors of complete pain recovery at 1 year after US-PICT.

Furthermore, an UpToDate review on “Calcific tendinopathy of the shoulder” (Prestgaard and Moosmayer, 2021) states that “Barbotage is a US-guided lavage technique that involves breaking up and then aspirating pieces of the calcific deposit. This approach can be used for chronic and acute, painful cases of calcific tendinopathy. It is performed on an outpatient basis under local anesthesia, often in combination with a glucocorticoid injection. This combination of interventions both removes part or all of the calcification and treats the resulting inflammation”.

Pectoralis Nerve Block (PEC 1 and PEC 2) for the Management of Post-Operative Pain Following Mastectomy / Sternotomy for Cardiac Surgery

In a single-case report, Yalamuri et al (2017) stated patients undergoing minimally invasive cardiac surgery have the potential for significant pain from the thoracotomy site. These investigators reported the successful use of pectoral nerve block types I and II (PECS I and II) as rescue analgesia in a patient undergoing minimally invasive mitral valve repair. The subject was a 78-year old man, with no history of chronic pain, underwent mitral valve repair via right anterior thoracotomy for severe mitral regurgitation. After extubation, he complained of 10/10 pain at the incision site that was minimally responsive to intravenous (IV) opioids. He needed supplemental oxygen because of poor pulmonary mechanics, with shallow breathing and splinting due to pain, and subsequent intensive care unit (ICU) re-admission. US-guided PECS I and II blocks were carried out on the right side with 30-ml of 0.2 % ropivacaine with 1:400,000 epinephrine. The blocks resulted in near-complete chest wall analgesia and improved pulmonary mechanics for about 24 hours. After the single-injection blocks regressed, a 2nd set of blocks was carried out with 266 mg of liposomal bupivacaine mixed with bupivacaine. This 2nd set of blocks provided extended analgesia for an additional 48 hours. The patient was weaned rapidly from supplemental oxygen after the blocks because of improved analgesia. These researchers noted that PECS nerve blocks had been described in the setting of breast surgery to provide chest wall analgesia. They reported the first successful use of PECS nerve blocks to provide effective chest wall analgesia for a patient undergoing minimally invasive cardiac surgery with thoracotomy. The authors concluded that these blocks may provide an important non-opioid option for the management of pain during recovery from minimally invasive cardiac surgery.

In a prospective RCT, Neethu et al (2018) examined the analgesic efficacy of Us-guided combined pectoral nerve blocks (PECS) I and II in patients scheduled for surgery for breast cancer. A total of 60 American Society of Anesthesiologists (ASA) status I to II women, aged 18 to 70 years were enrolled in this study. Patients were randomized into 2 groups (30 patients in each group), PECS (P) group and control (C) group. In group P, patients received both general anesthesia and US-guided combined PECS I and II. In group C, patients received only general anesthesia (GA). These researchers noted pain intensity at rest and during abduction of the ipsilateral upper limb, incidence of post-operative nausea and vomiting (PONV); patient's satisfaction with post-operative analgesia and maximal painless abduction at different time-intervals in both groups. There was significant decrease in the total amount of fentanyl requirement in the in P group {(140.66 ± 31.80 μg) and (438 ± 71.74 μg)} in comparison to C group {(218.33 ± 23.93 μg) and (609 ± 53.00 μg)} during intra-operative and post-operative period up to 24 hours, respectively. The time to first analgesic requirement was also more in P group (44.33 ± 17.65 mins) in comparison to C group (10.36 ± 4.97 mins) during post-operative period. There was less limitation of shoulder movement (pain free mobilization) on the operative site at 4 and 5 hours after surgery in P group in comparison to C group. However there was no difference in the incidence of PONV (22 out of 30 patients in group P and 20 out of 30 patients in group C) but patients in group P had a better satisfaction score with post-operative analgesia than C group having a p value of < 0.001(Score 1; 5 versus 20; Score 2; 12 versus 9; Score 3; 13 versus 1). The authors concluded that US-guided combined PECS were an effective modality of analgesia for patients undergoing breast surgeries during peri-operative period.

Versyck et al (2019) noted that surgery is the primary therapeutic intervention for breast cancer and can result in significant post-operative pain. These investigators searched the current literature and performed a meta-analysis in order to compare the analgesic efficacy of the PECS II block with systemic analgesia alone and with a thoracic paravertebral block for breast cancer surgery. Primary outcome was post-operative opioid consumption in the first 24 hours after surgery. Secondary outcomes were pain scores at 0, 3, 6, 9 and 24 hours after surgery, intra-operative opioid consumption, time to first analgesic request and incidence of post-operative nausea and vomiting. They identified 13 RCTs that included 815 patients. The Pecs II block significantly reduced post-operative opioid consumption (standardized mean difference [SMD]: -13.64 mg oral morphine equivalents; 95 % confidence interval [CI]: -21.22 to -6.05; p < 0.01) and acute post-operative pain at all intervals in the first 24 hours after surgery compared with systemic analgesia alone. Compared with the thoracic paravertebral block, the Pecs II block resulted in similar post-operative opioid consumption (SMD: -8.73 mg oral morphine equivalents; 95 % CI: -18.16 to 0.69; p = 0.07) and post-operative pain scores after first measurement. The authors concluded that the PECSs II block offered improved analgesic efficacy compared with systemic analgesia alone and comparable analgesic efficacy to a thoracic paravertebral block for breast cancer surgery.

Zhao et al (2019) stated that many types of regional nerve blocks have been used during anesthesia for modified radical mastectomy. In recent years, the use of pectoral nerve (PECS) block has gained importance in post-operative analgesia, but there are still controversies regarding its efficacy. There is especially no consensus on the optimal type of PECS block to be used. These researchers evaluated the analgesic efficacy of the PECS block after radical mastectomy. They searched PubMed, Embase, and the Cochrane library for RCTs for studies regarding PECS versus GA that were published prior to May 31, 2018. Outcome measures such as intra- and post-operative consumption of opioids, PONV, need for post-operative rescue analgesia, and pain scores were analyzed. After quality evaluation and data extraction, a meta-analysis was performed using Review Manager 5.3 software, and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system was used for rating the quality of evidence. A total of 8 RCTs and 2 cohort studies involving 993 patients were eligible. Compared with the GA group, the PECS block group effectively reduced the intra-operative and post-operative use of opioid drugs, incidence of PONV, need for post-operative rescue analgesia, and pain scores within 0 to 6 hours after surgery. However, subgroup analysis showed that PECS I block did not have a significant advantage in reducing the intra- and post-operative consumption of opioids. Results for each outcome indicator were confirmed as having a high or moderate level of evidence. The authors concluded that even considering the limitations (evaluations of efficacy in different age groups and for chronic pain were not carried out) of this meta-analysis, it can be concluded that the PECS II block is an effective anesthetic regimen in modified radical mastectomy that can effectively reduce the intra- and post-operative consumption of opioids, post-operative PONV, and the need for post-operative rescue analgesia and can alleviate early pain (0 to 6 hours) after surgery.

In a prospective, randomized, single-blinded study, Altıparmak et al (2019) compared the effects of US-guided modified PECS block and erector spinae plane (ESP) block on post-operative opioid consumption, pain scores, and intra-operative fentanyl need of patients undergoing unilateral modified radical mastectomy surgery. A total of 40 patients (ASA I-II) were allocated to 2 groups. After exclusion, 38 patients were included in the final analysis (18 patients in the PECS groups and 20 in the ESP group). Modified pectoral nerve block was performed in the PECS group and erector spinae plane block was performed in the ESP group. Post-operative tramadol consumption and pain scores were compared between the groups. Also, intra-operative fentanyl need was measured. Post-operative tramadol consumption was 132.78 ± 22.44 mg in PECS group and 196 ± 27.03 mg in ESP group (p = 0.001); NRS scores at the 15th and 30th mins were similar between the groups. However, median NRS scores were significantly lower in PECS group at the post-operative 60th min, 120th min, 12th hour and 24th hour (p = 0.024, p = 0.018, p = 0.021 and p = 0.011, respectively). Intra-operative fentanyl need was 75 mg in PECS group and 87.5 mg in ESP group. The difference was not statistically significant (p = 0.263). The authors concluded that modified PECS block reduced post-operative tramadol consumption and pain scores more effectively than ESP block after radical mastectomy surgery.

Ueshima et al (2019) noted that since the original description in 2011, the array of PECS has evolved. The PECS block in conjunction with GA can decrease an additional analgesic in peri-operative period for breast cancer surgeries. Current literature on the PECS block has reported 3 several types (PECS I, PECS II, and serratus plane blocks). The PECS I block is the same as to the first injection in the PECS II block. The second injection in the PECS II block and the serratus plane block blocks intercostal nerves (T2 to T6) and provides an analgesic for the breast cancer surgery. However, the PECS I block (or first injection in the PECS II block) has no analgesic, because both lateral and medial pectralis nerve blocks are motor nerves. PECS block in previous reports, when added to opioid-based GA, may improve analgesia and decrease narcotic use for breast cancer surgery. Moreover, PECS block compares favorably with other regional techniques for selected types of surgery. A major limitation of the PECS block is that it could not block the internal mammary region. Thus, some studies have reported its ability to block the anterior branches of the intercostal nerve. The authors concluded that PECS block is an effective analgesic tool for the anterolateral chest; in particular, the PECS block can provide more effective analgesia for breast cancer surgery.

Senapathi et al (2019) stated that combined regional and GA are often used for the management of breast cancer surgery. Thoracic spinal block, thoracic epidural block, thoracic paravertebral block, and multiple intercostal nerve blocks are the regional anesthesia techniques that have been used in breast surgery, but some anesthesiologists are not comfortable because of the complication and side effects. In 2012, Blanco et al introduced pectoralis nerve (PECS) II block or modified PECS block as a novel approach to breast surgery. These researchers determined the effectiveness of combined US-guided PECS II block and GA for reducing intra- and post-operative pain from modified radical mastectomy. A total of 50 patients undergoing modified radical mastectomy with GA were divided into 2 groups randomly (n = 25), to either PECS (P) group or control (C) group. Ultrasound-guided PECS II block was done with 0.25 % bupivacaine (P group) or 0.9 % NaCl (C group). Patient-controlled analgesia (PCA) was used to control post-operative pain. Intra-operative opioid consumption, post-operative visual analog scale (VAS) score, and post-operative opioid consumption were measured. Intra-operative opioid consumption was significantly lower in P group (p ≤ 0.05); VAS score at 3, 6, 12, and 24 hours post-operative were significantly lower in P group (p ≤ 0.05); 24 hours post-operative opioid consumption was significantly lower in P group (p ≤ 0.05). There were no complications following PECS block in both groups, including pneumothorax, vascular puncture, and hematoma. The authors concluded that combined US-guided PECS II block and GA were effective in reducing pain both intra- and post-operatively in patients undergoing modified radical mastectomy.

Lovett-Carter et al (2019) noted that several studies have evaluated the effect of PECS to improve post-operative analgesia following breast cancer surgery resulting in contradictory findings. These investigators examined the effect of PECS blocks on post-operative analgesia in women following mastectomies. They performed a quantitative systematic review in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Articles of RCTs that compared PECS block (types I and II) to a control group in patients undergoing mastectomy were included. The primary outcome was total opioid consumption 24 hours after surgery. Secondary outcomes included pain scores and side effects. Meta-analysis was performed using the random effect model. A total of 7 RCTs with 458 patients were included in the analysis. The effect of PECS blocks on post-operative opioid consumption compared with control revealed a significant effect, weighted mean difference (WMD) (95 % CI: -4.99 (-7.90 to -2.08) mg intravenous morphine equivalents (p = 0.001). In addition, post-operative pain compared with control was reduced at 6 hours after surgery: WMD (95 % CI): -0.72 (-1.37 to -0.07), p = 0.03, and at 24 hours after surgery: WMD (95 % CI): -0.91 (-1.81 to -0.02), p = 0.04. The authors concluded that this quantitative analysis of RCTs demonstrated that the PECS block was effective for reducing post-operative opioid consumption and pain in patients undergoing mastectomy. The PECS block should be considered as an effective strategy to improve analgesic outcomes in patients undergoing mastectomies for breast cancer treatment.

In a prospective, randomized, single-blind, single-center study, Kaushal et al (2019) compared the relative effectiveness of US-guided serratus anterior plane block (SAPB), pectoral nerves (PECS) II block, and intercostal nerve block (ICNB) for the management of post-thoracotomy pain in pediatric cardiac surgery. The trial comprised 108 children with congenital heart disease requiring surgery via a thoracotomy. Subjects were randomly assigned to 1 of the 3 groups: SAPB, PECS II, or ICNB. All subjects received 3 mg/kg of 0.2 % ropivacaine for US-guided block after induction of anesthesia. Post-operatively, IV paracetamol was used for multi-modal and fentanyl was used for rescue analgesia. A modified objective pain score (MOPS) was evaluated at 1, 2, 4, 6, 8, 10, and 12 hours after extubation. The early mean MOPS at 1, 2, and 4 hours were similar in the 3 groups. The late mean MOPS was significantly lower in the SAPB group compared with that of the ICNB group (p < 0.001). The PECS II group also had a lower MOPS compared with the ICNB group at 6, 8, and 10 hours (p < 0.001), but the MOPS was comparable at hour 12 (p = 0.301). The requirement for rescue fentanyl was significantly higher in ICNB group in contrast to the SAPB and PECS II groups. The authors concluded that SAPB and PECS II fascial plane blocks were equally effective in post-thoracotomy pain management compared with ICNB; moreover, they had the additional benefit of being longer lasting and were as easily carried out as the traditional ICNB.

Gaweda et al (2020) stated that effective post-operative pain control remains a challenge for patients undergoing cardiac surgery. Novel regional blocks may improve pain management for such patients and can shorten their hospital LOS. In a prospective, double-blinded RCT, these researchers compared post-operative pain intensity in patients undergoing cardiac surgery with either erector spinae plane (ESP) block or combined ESP and pectoralis nerve (PECS) blocks. This trial included 30 patients undergoing mitral/tricuspid valve repair via mini-thoracotomy. Patients were randomly allocated to one of two groups: ESP or PECS + ESP group (1:1 randomization). Patients in both groups received a single-shot, US-guided ESP block. Subjects in PECS + ESP group received additional PECS blocks. Each patient had to be extubated within 2 hours from the end of the surgery. Pain was treated via a patient-controlled analgesia (PCA) pump. The primary outcome was the total oxycodone consumption via PCA during the 1st post-operative day. The secondary outcomes included pain intensity measured on the VAS, patient satisfaction, Prince Henry Hospital Pain Score (PHHPS), and spirometry. Patients in the PECS + ESP group used significantly less oxycodone than those in the ESP group: median 12 [IQR: 6 to 16] mg versus 20 [IQR: 18 to 29] mg (p = 0.0004). Moreover, pain intensity was significantly lower in the PECS + ESP group at each of the 5 measurements during the 1st post-operative day. Patients in the PECS + ESP group were more satisfied with pain management. No difference was observed between both groups in PHHPS and spirometry. The authors concluded that the addition of PECS blocks to ESP reduced consumption of oxycodone via PCA, reduced pain intensity on the VAS, and increased patient satisfaction with pain management in patients undergoing mitral/tricuspid valve repair via mini-thoracotomy.

Piriformis Muscle Injection

In a cadaveric study, Finnoff et al (2008) compared the accuracy of ultrasound (US)-guided piriformis injections with fluoroscopically guided contrast-controlled piriformis injections. A total of 20 piriformis muscles in 10 un-embalmed cadavers were injected with liquid latex using both fluoroscopically guided contrast-controlled and US-guided injection techniques. All injections were performed by the same experienced individual. Two different colors of liquid latex were used to differentiate injection placement for each procedure, and the injection order was randomized. The gluteal regions were subsequently dissected by an individual blinded to the injection technique. Colored latex observed within the piriformis muscle, sheath, or both was considered an accurate injection. A total of 19 of 20 US-guided injections (95 %) correctly placed the liquid latex within the piriformis muscle, whereas only 6 of the 20 fluoroscopically guided contrast-controlled injections (30 %) were accurate (p = 0.001). The liquid latex in 13 of the 14 missed fluoroscopically guided contrast-controlled piriformis injections and the single missed US-guided injection was found within the gluteus maximus muscle. In the single remaining missed fluoroscopically guided contrast-controlled piriformis injection, the liquid latex was found within the sciatic nerve. The authors concluded that in this cadaveric model, US-guided piriformis injections were significantly more accurate than fluoroscopically guided contrast-controlled injections. Despite the use of bony landmarks and contrast, most of the fluoroscopically attempted piriformis injections were placed superficially within the gluteus maximus. Clinicians performing piriformis injections should be aware of the potential pitfalls of fluoroscopically guided contrast-controlled piriformis injections and consider using US guidance to ensure correct needle placement.

The authors stated that this study had several drawbacks. First, a single investigator performed all injections. The investigator was pain medicine fellowship-trained, was board-certified in pain medicine, and had extensive procedural experience with both fluoroscopically guided and US‐guided procedures. In consideration of the relatively poor accuracy of the fluoroscopically guided piriformis injection, it was worth noting that he had several years' more experience with the fluoroscopic than with the US technique. Nonetheless, the results of this investigation may not be applicable to other clinicians with different training and experiential backgrounds. Second, this investigation used un-embalmed cadavers rather than live participants. The study necessitated 2 injections in each piriformis muscle and "surgical" confirmation of injectate placement via dissection, a design that could not be completed in live individuals. These researchers did not think that the use of cadavers appreciably affected their findings. Their contrast patterns were similar to those observed in live individuals, so it was unlikely that the cadaver model biased the results against fluoroscopy. On the contrary, the inability to take full advantage of the dynamic soft tissue imaging capabilities of US may have negatively biased the accuracy of the US technique. For example, the inferior gluteal artery as imaged via Doppler techniques may be used in live persons as a reference mark for the inferior border of the piriformis muscle as well as the location of the sciatic nerve. These investigators thought that the results of this study appeared to be transferable to the clinical setting.

Blunk et al (2013) noted that patients presenting with buttock pain syndromes are common. Up to 8 % of these conditions may be attributed to piriformis syndrome. Included in several therapeutic and diagnostic approaches, injections directly into the piriformis muscle may be performed. Because the muscle lies very close to neurovascular structures, electromyographic (EMG), fluoroscopic, computed tomographic (CT), and magnetic resonance imaging (MRI) guidance have been employed. In few studies, an US-guided technique was used to inject a local anesthetic into the piriformis muscle without impairing adjacent neuronal structures. In a feasibility study in healthy human subjects, These researchers confirmed US-guided injections by MRI. In 10 male human subjects, US-guided injections of 3 ml of a local anesthetic into the piriformis muscle were performed. Directly after the injection, the subjects were placed in an MRI scanner, and the placement of the liquid depot was confirmed by MRI imaging. Somatosensory deficits were evaluated after the injection. The MRI showed that 9 of 10 of the injections were correctly placed within the piriformis muscle. The distance of the depot to the sciatic nerve decreased over time due to dispersion, but the nerve itself was not reached in the MRI. Only 1 subject experienced slight, short-term sensorimotor deficits. The authors concluded that MRI confirmed the correct placement of the local anesthetic within the muscle. The dispersion of the fluid 30 mins after the injection could be visualized. Moreover, only 1 subject experienced slight motor deficits without anatomical correlate. These researchers stated that this US-guided method will be further employed in ongoing clinical studies.

Fabregat et al (2014) noted that approximately 6 % to 8 % of lumbar pain cases, whether associated with radicular pain or not, may be attributed to the presence of piriformis muscle syndrome. Available treatments, among others, include pharmacotherapy, physical therapy, and injections of different substances into the muscle. Various methods have been used to confirm correct needle placement during these procedures, including EMG, fluoroscopy, CT, or MRI. Ultrasonography has now become a widely used technique and therefore may be an attractive alternative for needle guidance when injecting this muscle. In a feasibility study, these researchers examined the reliability of US in piriformis injection of patients with piriformis syndrome. A tot of 10 patients with piriformis muscle syndrome were injected with botulinum toxin A (BTX-A) using a US-guided procedure. Then patients were administered 2 ml iodinated contrast and were then transferred to the CT scanner, where they underwent pelvic and hip imaging to assess intra-muscular (IM) distribution of the iodinated contrast. Of all 10 study patients (8 women, 2 men), 9 had IM or intra-fascial contrast distribution. Distribution did not go deeper than the piriformis muscle in any of the patients. The absence of contrast (intravascular injection) was not observed in any case. The authors concluded that US-guided puncture may be a reliable and simple procedure for injection of the piriformis muscle, as long as good education and training are provided to the operator. These researchers stated that US has a number of advantages over traditional approaches, including accessibility and especially no ionizing radiation exposure for both health care providers and patients. Moreover, they noted that published data regarding US-guided treatments were still very limited; and further studies should focus on outcome and safety of US-guided pain interventions compared to traditional imaging techniques such as fluoroscopy.

Fowler et al (2014) stated that piriformis muscle injections are most often performed using fluoroscopic guidance; however, US guidance has recently been described extensively in the literature. No direct comparisons between the 2 techniques have been performed. In a randomized, comparative trial, these researchers compared the efficacy and efficiency of fluoroscopic- and US-guided techniques. A total of 28 patients with a diagnosis of piriformis syndrome, based on history and physical examination, who had failed conservative treatment were enrolled in the study. Patients were randomized to receive the injection either via US or fluoroscopy. Injections consisted of 10 ml of 1 % lidocaine with 80 mg of triamcinolone. The primary outcome measure was numeric pain score (NPS), and secondary outcome measures included functional status as measured by the Multidimensional Pain Inventory, patient satisfaction as measured by the Patient Global Impression of Change scale, and procedure timing characteristics. Outcome data were measured pre-procedure, immediately post-procedure, and 1 to 2 weeks and 3 months post-procedure. These investigators found no statistically significant differences in NPS, patient satisfaction, procedure timing characteristics, or most functional outcomes when comparing the 2 techniques. Statistically significant differences between the 2 techniques were found with respect to the outcome measures of household chores and outdoor work. The authors concluded that US-guided piriformis injections provided similar outcomes to fluoroscopically guided injections without differences in imaging, needling, or overall procedural times.

Misirlioglu et al (2015) stated that piriformis syndrome (PS), which is characterized by pain radiating to the gluteal region and posterior leg, is accepted as one of the causes of sciatalgia. Although the importance of local piriformis muscle injections whenever PS is clinically suspected has been shown in many studies, there are not enough studies considering the clinical efficacy of these injections. In a prospective, double-blinded, randomized controlled trial (RCT), these investigators examined the differences between local anesthetic (LA) and LA + corticosteroid (CS) injections in the treatment of PS. A total of 57 patients having unilateral hip and/or leg pain with positive FAIR test and tenderness and/or trigger point at the piriformis muscle were evaluated. Out of 50 patients randomly assigned to 2 groups, 47 patients whose pain resolved at least 50 % from the baseline after the injection were diagnosed as having PS. The first group (n = 22) received 5 ml of lidocaine 2 % while the second group (n = 25) received 4 ml of lidocaine 2 % + 1 ml of betamethasone under US-guidance. Outcome measures included numeric rating scale (NRS) and Likert analogue scale (LAS). No statistically significant difference (p > 0.05) was detected between the groups in NRS score values at resting (p = 0.814), night (p = 0.830), and in motion (p = 0.145), and LAS values with long duration of sitting (p = 0.547), standing (p = 0.898), and lying (p = 0.326) with evaluations at baseline, first week, and first and third months after the injection. A statistically highly significant (p < 0.005) reduction of pain was evaluated through NRS scores at resting (p = 0.001), in motion (p = 0.001), and at night (p = 0.001) and LAS values with long duration of sitting (p = 0.001), standing (p = 0.001), and lying (p = 0.001) in both of the groups. The authors concluded that LA injections for the PS were found to be clinically effective. However, addition of CS to LA did not give an additional benefit.

Payne (2016) described the techniques for performing US-guided procedures in the hip region, including intra-articular hip injection, iliopsoas bursa injection, greater trochanter bursa injection, ischial bursa injection, and piriformis muscle injection. The author stated that US is commonly used to evaluate hip region pathologic conditions and to guide interventions in the hip region for diagnostic and therapeutic purposes; US confers many advantages compared with other commonly used imaging modalities, including real-time visualization of muscles, tendons, bursae, neurovascular structures, and the needle during an intervention. The author stated that US-guided injection techniques have been described for many commonly performed procedures in the hip region, and many studies have been performed demonstrating the safety and accuracy of these techniques.

In a prospective study, Terlemez and Ercalık (2019) examined the effect of a piriformis injection on neuropathic pain in patients with PS. A total of 30 patients with unilateral hip and/or leg pain, a positive FAIR test (increased H-reflex latency with Flexion, Adduction and Internal Rotation), and a trigger point at the piriformis muscle were enrolled in this study. All of the patients exhibited neuropathic pain scored according to the Douleur Neuropathique 4 (DN4) of greater than or equal to 4 for at least 6 months. All of the patients received 4 ml of lidocaine 2 % + 1 ml of betamethasone to the piriformis muscle under US-guidance. The NRS, DN4, and the painDETECT (PD) questionnaire were used for outcome assessment. A statistically significant improvement was observed in all scores (p < 0.001) when both first week and first month results were compared with the baseline values. Comparison of the first week results with those of the first month revealed a statistically significant improvement in only the NRS and PD scores (p < 0.001). The greatest improvement in all scores was observed in the first week after the injection. A mild increase was observed in all scores at the first month compared to the first week. The authors concluded that a piriformis injection was found to be effective for both somatic and neuropathic pain in PS patients.

Furthermore, an UpToDate review on "Approach to hip and groin pain in the athlete and active adult" (Johnson, 2020) states that "Treatment begins with physical therapy involving strengthening of the pelvic and hip region and stretching of the piriformis. Appropriate analgesics for neuropathic pain are taken as needed. Physical therapy is effective in the majority of cases. Ultrasound-guided glucocorticoid injections have been beneficial in some cases, and botulinum toxin injections have also been used. Surgery (typically a piriformis tenotomy) may be considered if symptoms are debilitating and persist despite conservative therapy".

Popliteal Nerve Block

Sinha and Chan (2004) stated that US is a novel method of nerve localization but its use for lower extremity blocks appeared limited with only reports for femoral 3-in-1 blocks. These investigators reported a case series of popliteal sciatic nerve blocks using US guidance to illustrate the clinical usefulness of this technology. The sciatic nerve was localized in the popliteal fossa by US imaging in 10 patients using a 4- to 7-MHz probe and the Philips ATL HDI 5,000 unit. Ultrasound imaging showed the sciatic nerve anatomy, the point at which it divides, and the spatial relationship between the peroneal and tibial nerves distally. Needle contact with the nerve(s) was further confirmed with nerve stimulation. Circumferential local anesthetic spread within the fascial sheath after injection appeared to correlate with rapid onset and completeness of sciatic nerve block. The authors concluded that their preliminary experience suggested that US localization of the sciatic nerve in the popliteal fossa was a simple and reliable procedure. It helped guide block needle placement and assessed local anesthetic spread pattern at the time of injection.

Perlas et al (2008) noted that real time US guidance is a recent development in the area of peripheral nerve blockade. There are limited data from prospective randomized trials comparing its efficacy to that of traditional nerve localization techniques. In the present study, these researchers tested the hypothesis that US guidance improved the success rate of sciatic nerve block at the popliteal fossa when compared with a nerve stimulator-guided technique. After Institutional Research Ethics Board approval and informed consent, a total of 74 patients undergoing elective major foot or ankle surgery were randomly assigned to receive a sciatic nerve block at the popliteal fossa guided by either US (group US, transverse view, needle in plane approach above the sciatic nerve bifurcation), or nerve stimulation (group NS, single injection, 10 cm proximal to the knee crease). A standardized local anesthetic admixture (15 ml of 2 % lidocaine with 1:200,000 epinephrine and 15 ml of 0.5 % bupivacaine) was used. Sensory and motor function was assessed by a blinded observer at pre-determined intervals for up to 1 hour. Block success was defined as a loss of sensation to pinprick within 30 mins in the distribution of both tibial and common peroneal nerves. Group US had a significantly higher block success rate than group NS (89.2 % versus 60.6 %, p = 0.005), while the procedure time was similar. The authors concluded that US guidance enhanced the quality of popliteal sciatic nerve block compared with single injection, nerve stimulator-guided block using either a tibial or peroneal endpoint; US guidance resulted in higher success, faster onset, and progression of sensorimotor block, without an increase in block procedure time, or complications.

van Geffen et al (2009) stated that the direct visualization of nerves and adjacent anatomical structures may make US the preferred method for nerve localization. In a prospective, randomized study, these investigators examined if, for distal sciatic nerve block in the popliteal fossa, an US-guided technique would result in the use of less local anesthetic without changing block characteristics and quality. Using electrical nerve stimulation or US guidance, the nerve was identified in 2 groups of 20 patients scheduled for lower limb surgery. Hereafter lignocaine 1.5 % with adrenaline 5 microg/ml was injected. The attending anesthesiologist assessed the injected volume. Significantly less local anesthetic was injected in the US group compared to the nerve stimulation group (17 versus 37 ml, p < 0.001), while the overall success rate was increased (100 % versus 75 %; p = 0.017). The authors concluded that the use of US localization for distal sciatic nerve block in the popliteal fossa reduced the required dose of local anesthetic significantly, and was associated with a higher success rate compared to nerve stimulation without changing block characteristics.

Bendtsen et al (2011) tested the hypothesis that US-guided catheter placement improved the success rate of continuous sciatic nerve sensory blockade compared with catheter placement with nerve stimulation guidance. After research ethics committee approval and informed consent, a total of 100 patients scheduled for elective major foot and ankle surgery were randomly allocated to popliteal catheter placement either with US or nerve stimulation guidance. The primary outcome was the success rate of sensory block the first 48 post-operative hours. Successful sensory blockade was defined as sensory loss in both the tibial and common peroneal nerve territories at 1, 6, 24, and 48 hours post-operatively. The US group had significantly higher success rate of sensory block compared with the nerve stimulation group (94 % versus 79 %, p = 0.03). US compared with nerve stimulation guidance also entailed reduced morphine consumption (median of 18 mg [range of 0 to 159 mg] versus 34 mg [range of 0 to 152 mg], respectively, p = 0.02), fewer needle passes (median of 1 [range of 1 to 6] versus 2 [range of 1 to 10], respectively, p = 0.0005), and greater patient satisfaction (median numeric rating scale 9 [range of 5 to 10] versus 8 [range of 3 to 10)] respectively, p = 0.0006) during catheter placement. The authors concluded that US guidance used for sciatic catheter placement improved the success rate of sensory block, number of needle passes, patient satisfaction during catheter placement, and morphine consumption compared with nerve stimulation guidance.

In a prospective, randomized study, Cataldo et al (2012) compared the success rate and performance time of popliteal block during resident's training for regional anesthesia by using nerve stimulation (NS) or combined nerve stimulation and US (NS + US). A total of 70 adult patients undergoing hallux valgus surgery were randomly assigned to receive sciatic nerve block at popliteal fossa with US+NS or NS alone with a double injection technique for peroneal and tibial branches, respectively. Two residents experienced with nerve stimulator performed the procedures after a learning phase concerning US. A local anesthetic solution, containing 10 ml of 0.75 % ropivacaine and 10 ml of 2 % lidocaine was used: 12 ml were infiltrated close the tibial nerve, and 8ml were infiltrated close the common peroneal nerve. Block success rate, sensory block onset time, block performance time were evaluated. Recourse to general anesthesia was considered as failure. No differences were detected in success rate and onset time of sensory block between the 2 groups (p > 0.05). The time to block tibial nerve and the overall block time were significantly faster in US+NS group (p < 0.05). The authors concluded that US guidance for popliteal nerve block resulted in similar success rate with a faster procedure time when compared with nerve stimulator, thus providing a possible effect on resident education and operating room efficiency.

In a randomized, single-blinded, clinical trial, Lam et al (2014) compared procedural times and related outcomes for US- versus nerve stimulation-guided lateral popliteal-sciatic nerve blockade specifically in obese patients. With Institutional Review Board approval and informed consent, patients with a body mass index (BMI) greater than 30 kg/m(2) who were scheduled for foot/ankle surgery and desiring a peripheral nerve block were offered enrollment. Study patients were randomly assigned to receive a lateral popliteal-sciatic nerve block under either US or nerve stimulation guidance. The patient and assessor were blinded to group assignment. The primary outcome was procedural time in seconds. Secondary outcomes included number of needle re-directions, procedure-related pain, patient satisfaction with the block, success rate, sensory and motor onset times, block duration, and complication rates. A total of 24 patients were enrolled and completed the study. All patients had successful nerve blocks. The mean procedural times (SD) were 577 (57) seconds under nerve stimulation and 206 (40) seconds with US guidance (p <0 .001; 95 % CI: 329 to 412 seconds). Patients in the US group had fewer needle re-directions and less procedure-related pain, required less opioids, and were more satisfied with their block procedures. There were no statistically significant differences in other outcomes. The authors concluded that the findings of this study showed that, for obese patients undergoing lateral popliteal-sciatic nerve blocks, US guidance reduced the procedural time and procedure-related pain and increased patient satisfaction compared to nerve stimulation while providing similar block characteristics.

In a prospective, randomized study, Karaarslan et al (2016) compared the efficacy, post-operative pain scores, adverse effects, additional analgesic requirements, and patient satisfaction scores of US-guided sciatic nerve block by popliteal approach with spinal anesthesia for hallux valgus correction surgery. A total of 60 patients scheduled for hallux valgus correction surgery were enrolled in this trial. Unilateral spinal block was performed on patients in the spinal anesthesia group. Popliteal block group patients received popliteal sciatic nerve block with guidance by both nerve stimulator and US. Durations of anesthetic and operative interventions and time until the initiation of surgery were recorded for both groups. Pain magnitude of the patients at the second, fourth, sixth, 12th, and 24th hours following anesthetic interventions were assessed with a visual analog scale (VAS). Adverse effects such as post-operative urinary retention and post-dural puncture headache were recorded. Also, patient satisfaction was recorded. Patients were interviewed by phone for anesthetic and operative complications at 72 hours post-operatively. Spinal anesthesia group patients exhibited hypotension, bradycardia, post-dural puncture headache, and urinary retention rates of 6.6 %, 3.3 %, 10 %, and 3.3 %, respectively. Popliteal block group patients showed none of these adverse effects. Moreover, VAS scores of the patients at the second, fourth, sixth, and 12th hours were significantly lower (p < 0.001, p = 0.003, p < 0.001, p < 0.001, respectively), post-operative first analgesic requirement times were significantly longer (p < 0.001), and pain satisfaction scores were significantly higher (p < 0.001) in the popliteal block group. The authors concluded that given the complications related to spinal anesthesia and its insufficiency to maintain analgesia postoperatively, they believed the preferred anesthetic method should be peripheral nerve blocks for hallux valgus correction surgeries. Level of Evidence = I.

Quadratus Lumborum Nerve Block for Post-Operative Pain Control After Abdominal Surgery

In a prospective RCT, Ishio et al (2017) determined the efficacy of US-guided posterior quadratus lumborum block (QLB) in treating post-operative pain following laparoscopic gynecologic surgery. A total of 70 adult patients scheduled for elective laparoscopic gynecological surgery under general anesthesia were enrolled in this trial. Patients were randomly assigned to either the QLB group or control group. In the QLB group, patients underwent posterior QLB with 20 ml of 0.375 % ropivacaine on each side. Patients were blinded to treatment. At 0, 1, 3, and 24 hours after anesthesia recovery, evaluator recorded the severity of post-operative pain in movement and at rest using a Numeric Rating Scale (NRS). These researchers also evaluated the severity of nausea using NRS and number of additional analgesics. Immediately after recovery from anesthesia, the NRS score for pain in movement did not differ significantly between groups; NRS scores for pain both in movement and at rest were significantly higher in the control group than in the QLB group at 1, 3, and 24 hours after recovery from anesthesia. The authors concluded that these findings suggested that posterior QLB significantly reduced post-operative pain in movement and at rest following laparoscopic gynecologic surgery.

Hussein (2018) stated that QLB has 4 approaches. However, there is difference between the 4 approaches regarding efficacy, safety and adverse effects. This investigator compared the analgesic effect between trans-muscular and intra-muscular approaches of the QLB in pediatric patients for elective lower abdominal surgery. A total of 54 patients aged 1 to 6 years were enrolled; patients of both genders were selected. Subjects were randomly classified into 2 groups: Group TQL included patients (n = 27) in whom bilateral QLB was performed using trans-muscular approach, and Group IQL included patients (n = 27) who underwent bilateral QLB using an intra-muscular approach. The primary outcome measure was the number of patients who required rescue analgesia in the first 24 hours. The secondary outcome measures were Face, Legs, Arms, Cry, Consolability (FLACC) score, heart rate, non-invasive blood pressure at 2, 4, 6, 12, and 24 hours post-operatively, and post-operative complications (e.g., local hematoma, quadriceps muscle weakness,). In the first 24 hours after surgery, 13 patients in the IQL group (48.1 %) required rescue analgesia, whereas only 5 patients in the TQL group (18.5 %) required rescue analgesia. The FLACC score was lower in the TQL group than the IQL group at all time intervals up to 24 hours post-operatively. In the TQL group, 8 patients (29.6 %) developed quadriceps weakness; whereas, only 1 patient (3.7 %) in the IQL group developed quadriceps weakness. The author concluded that TQL was better than IQL in the analgesic efficacy following the pediatric lower laparotomy.

Zhu et al (2019) stated that QLB is increasingly being used as a new abdominal nerve block technique. In some studies of mid and lower abdominal and hip analgesia, continuous QLB achieved favorable outcomes as an alternative to continuous intravenous analgesia with opioids. However, the use of continuous QLB for upper abdominal pain is less well characterized. In an open-label RCT, these investigators examined the effects of continuous anterior QLB (CQLB) on post-operative pain and recovery in patients undergoing open liver resection. A total of 63 patients underwent elective open liver resection were randomly divided into CQLB group (n = 32) and patient-controlled analgesia (PCA) group (n = 31). Patients in CQLB group underwent US-guided anterior QLB at the second lumbar vertebral transverse processes before general anesthesia, followed by post-operative CQLB analgesia. Patients in PCA group underwent continuous intravenous analgesia post-operatively. Post-operative NRS pain scores upon coughing and at rest, self-administered analgesic counts, rate of rescue analgesic use, time to first out-of-bed activity and anal flatus after surgery, and incidences of analgesic-related adverse effects were recorded. Post-operative NRS pain scores on coughing in CQLB group at different time-points and NRS pain score at 48 hours after surgery were significantly lower than those in PCA group (p < 0.05). Time to first out-of-bed activity and anal flatus after surgery in CQLB group were significantly earlier than those in PCA group (p < 0.05). No significant differences of post-operative self-administered analgesic counts, rate of post-operative rescue analgesic usage, or incidences of analgesic-related adverse effects were found between the 2 groups (p > 0.05). The authors concluded that US-guided anterior QLB significantly alleviated the pain during coughing after surgery, shortened the time to first out-of-bed activity and anal flatus, promoting post-operative recovery of the patients undergoing open liver resection.

Salama (2020) stated that adequate pain control after cesarean section (CS) is important to help the newly delivered mothers to feed and care their newborns together with early ambulation of the parturients to avoid the risk of thrombo-embolism and development of chronic abdominal and pelvic pain. In a RCT, these investigators compared the efficacy of QLB and intra-thecal morphine for post-operative analgesia after CS. A total of 90 pregnant women with a gestation of 37 weeks or more scheduled for elective CS were enrolled in this study. All subjects received spinal anesthesia, and after surgery, QLB was performed. They were randomly allocated to control group (CG, 0.1-ml saline added to spinal drug and 24-ml saline for QLB), intra-thecal morphine group (ITM, 0.1-mg morphine added to spinal drug and 24-ml saline for QLB), or QLB group (0.1-ml saline added to spinal drug and 24-ml 0.375 % ropivacaine for QLB). Integrated Analgesia Score (IAS), NRS at rest and during movement, morphine requirements in the first 48 hours, time to first morphine dose, time to first ambulation, and morphine related side effects were recorded. IAS and NRS scores at rest and during movements were significantly less in QLB and ITM than CG. Moreover, QLB had lower IAS and NRS scores at rest and during movements in comparison to ITM. Time to first morphine dose was significantly longer in QLB than in ITM and CG. Also, morphine requirements in the first 48 hours was significantly lower in QLB than ITM and CG (18.2 ± 9.6 mg in QLB versus and 42.8 ± 10.4 mg and 61 ± 12.9 mg in ITM and CG, respectively) (p = 0.001). No significant difference between the 3 groups regarding time to first ambulation (13.4 ± 1.8 hours in QLB versus 11.7 ± 1.9 hours in CG and 12.9 ± 1.6 hours in ITM). Incidence of morphine related side effects was significantly higher in ITM compared to CG and QLB. The authors concluded that QLB and intra-thecal morphine were effective analgesic regimens after CS. However, QLB provided better long lasting analgesia together with reduction of total post-operative morphine consumption.

Sato (2019) noted that US-guided QLB is a regional anesthetic technique that can provide peri-operative analgesia for all age groups, including pediatric patients undergoing abdominal surgery. This researcher hypothesized that the QLB would be as effective as a caudal block, the gold standard of pediatric lower abdominal regional anesthesia, in providing pain control after ureteral re-implantation but also have a longer duration. A total of 47 pediatric patients aged f 1 to 17 years undergoing bilateral ureteral re-implantation surgery via a low transverse incision were enrolled and randomized into the QLB and caudal block groups. All blocks were performed pre-operatively under general anesthesia. This investigator analyzed the following outcomes: the requirement for narcotic analgesics, pain score, episodes of emesis, and complications at 0, 4, 24, and 48 hours post-operatively. The study included 44 patients after excluding 3 who were ineligible. The fentanyl requirement for post-operative rescue analgesia during the first 24 hours was significantly lower in the QLB group than in the caudal block group (median [interquartile range (IQR)]: 0 [0 to 1] versus 3 [0 to 5], p = 0.016, 95 % confidence intervals (CI): -4 to 0); but not at 30 mins, 4 hours or 48 hours. No significant difference was observed in the pain scores or the incidence of interventions to treat nausea and vomiting during the entire period. No post-operative complication was observed. The author concluded that QLB was more effective in reducing the post-operative opioid requirement for rescue analgesia during the initial 24 hours than caudal ropivacaine/morphine.

Saphenous Nerve Block for Post-Operative Pain Control After Open Reduction and Internal Fixation of Trimalleolar Fracture

Manickam et al (2009) noted that saphenous nerve (SN) block can be technically challenging because it is a small and exclusively sensory nerve. Traditional techniques using surface landmarks and nerve stimulation are limited by inconsistent success rates. This descriptive prospective study examined the feasibility of performing an US-guided SN block in the distal thigh. After the research ethics board's approval and written informed consent, 20 patients undergoing ankle or foot surgery underwent US of the medial aspect of the thigh to identify the SN in the adductor canal, as it lies adjacent to the femoral artery (FA), deep to the sartorius muscle. An insulated needle was advanced in plane under real-time guidance toward the nerve. After attempting to elicit paresthesia with nerve stimulation, 2 % lidocaine with 1:200,000 epinephrine (5 ml) and 0.5 % bupivacaine (5 ml) were injected around the SN. The SN was identified in all patients, most frequently in an antero-medial position relative to the FA, at a depth of 2.7 +/- 0.6 cm and 12.7 +/- 2.2 cm proximal to the knee joint. Complete anesthesia in the SN distribution developed in all patients by 25 mins after injection. The authors concluded that in this small descriptive study, US-guided SN block in the adductor canal was technically simple and reliable, providing consistent nerve identification and block success. This appeared to be a small feasibility study.

Fredrickson et al (2011) stated that US guidance reduces the required local anesthetic volume for successful peripheral nerve blockade, but it is unclear whether this impacts post-operative analgesia. In a prospective, randomized, observer-blinded study, these researchers hypothesized that a low-volume US-guided ankle block would provide similar analgesia after foot surgery compared with a conventional-volume surface landmark technique. A total of 72 patients presenting for elective foot surgery under general anesthesia were randomized to receive a low-volume US-guided ankle block (n = 37; ropivacaine 0.5 % adjacent the anterior/posterior tibial arteries and short saphenous vein; subcutaneous infiltration around the saphenous and superficial peroneal nerves) or conventional-volume surface landmark guided technique (n = 35; 30-ml of ropivacaine 0.5 %). Patients received regular post-operative acetaminophen, diclofenac, and rescue tramadol. Assessment was in the recovery room and at 24 hours for pain and tramadol consumption. Mean (SD) total local anesthetic volume for the low-volume US group was 16 (2.1) ml. Block success in the recovery room was similar between groups (low-volume US 89 % versus conventional-volume landmark 80 %, p = 0.34; however, during the first 24 hours, numerically rated (0 to 10) "average pain" (median [10 to 90th percentiles] = 1 [0 to 4] versus 0 [0 to 2], p = 0.01), worst pain at rest (1 [0 to 6] versus 0 [0 to 2], p = 0.03), and the proportion of patients requiring rescue tramadol (% [95 % confidence interval (CI)]: 50 [34 to 46] versus 20 [10 to 36], p = 0.01) were higher in the low-volume US group. Numerically rated numbness, weakness, satisfaction, and procedural time were similar between groups. The authors concluded that low-volume US-guided ankle block was associated with a high block success rate after foot surgery; however, compared with a conventional volume (surface landmark) technique, the reduced local anesthetic volume marginally compromised post-operative analgesia during the first 24 hours.

Peterson et al (2020) noted that peri-articular injection or anesthesiologist-performed adductor canal block are commonly used for pain management after total knee arthroplasty (TKA). A surgeon-performed, intra-articular saphenous nerve block has been recently described. There is insufficient data comparing the efficacy and safety of these methods. In a retrospective, 2-surgeon cohort study, these researchers compared short-term peri-operative outcomes after primary TKA in 50 consecutive patients with surgeon-performed high-dose peri-articular injection and intra-articular saphenous nerve block (60-ml 0.5 % bupivacaine, 30-ml saline, 30-mg ketorolac) and 50 consecutive patients with anesthesiologist-performed adductor canal catheter (0.25 % bupivacaine 6 ml/hour infusion pump placed post-operatively with US guidance). Chart review assessed pain scores through POD #1, opioid use, length of stay (LOS), and short-term complications, including local anesthetic systemic toxicity. Statistical analysis was performed with 2-tailed Student's t-test. The high-dose peri-articular injection cohort had significantly lower pain scores in the post-anesthesia care unit (mean difference [MD] 1.4, p = 0.035), on arrival to the in-patient ward (MD 1.7, p = 0.013), and required less IV narcotics on the day of surgery (MD 6.5 MME, p = 0.0004). There was no significant difference in pain scores on POD #1, total opioid use, day of discharge, or short-term complications. There were no adverse events (AEs) related to the high-dose of bupivacaine. The authors concluded that compared with post-operative adductor canal block catheter, an intra-operative high-dose peri-articular block demonstrated lower pain scores and less IV narcotic use on the day of surgery. No difference was noted in pain scores on POD #1, time to discharge, or complications. There were no cardiovascular complications (local anesthetic systemic toxicity) despite the high-dose of bupivacaine injected. Level of Evidence = III. The US guidance in this study was provided to the adductor canal block group; not to the intra-articular saphenous nerve block group.

Scapular Thoracic Bursitis Injection

Osias et al (2018) noted that symptomatic scapulothoracic disorders, including scapulothoracic crepitus and scapulothoracic bursitis are uncommon disorders involving the scapulothoracic articulation that have the potential to cause significant patient morbidity. Scapulothoracic crepitus is the presence of a grinding or popping sound with movement of the scapula that may or may not be symptomatic, while scapulothoracic bursitis refers to inflammation of bursa within the scapulothoracic articulation. Both entities may occur either concomitantly or independently. Nonetheless, the constellation of symptoms manifested by both entities has been referred to as the snapping scapula syndrome. Various causes of scapulothoracic crepitus include bursitis, variable scapular morphology, post-surgical or post-traumatic changes, osseous and soft tissue masses, scapular dyskinesis, and postural defects. Imaging is an important adjunct to the physical examination for accurate diagnosis and appropriate treatment management. Non-operative management such as physical therapy and local injection can be effective for symptoms secondary to scapular dyskinesis or benign, non-osseous lesions. Surgical treatment is utilized for osseous lesions, or if non-operative management for bursitis has failed. Open, arthroscopic, or combined methods have been performed with good clinical outcomes.

Walter et al (2019) stated scapulothoracic pain is a common ailment, but the underlying cause can be difficult to diagnose in a timely manner, and treatment options are limited. These researchers retrospectively reviewed their experience using US-guided therapeutic scapulothoracic interval steroid injections to treat scapulothoracic pain and reviewed correlative MRI findings over a 5-year period. Although a variety of structural causes are known to cause scapulothoracic pain, in the authors’ experience, most cases lacked correlative imaging findings. The authors concluded that US-guided scapulothoracic interval injections provided a safe, easily performed diagnostic and therapeutic tool for treating patients with periscapular pain, providing at least short-term symptom relief.

Sciatic Nerve Block

An UpToDate review on "Lower extremity nerve blocks: Techniques" (Jeng and Rosenblatt, 2019a) states that "The sciatic nerve block provides complete anesthesia of the leg below the knee, with the exception of a strip of medial skin innervated by the saphenous nerve. Combined with femoral or saphenous nerve block, it provides analgesia for surgery of the distal anterior thigh; anterior knee; and lateral calf, ankle, or foot. The sciatic nerve block can be performed using either an anterior or a posterior approach, with similar success rates for surgery below the knee … Ultrasound-guided sciatic block – For an ultrasound-guided sciatic block, the ultrasound transducer is held transverse to the course of the nerve. The sciatic nerve can be blocked via a transgluteal (needle inserted just distal and deep to gluteus maximus muscle) or infragluteal (just below the level of the subgluteal crease) approach. For both approaches, the patient is placed in a position between lateral decubitus and prone, with the hip and knee flexed".

Serratus Plane Block for the Management of Post-Operative Pain Following Breast Surgery or Thoracotomy

Madabushi et al (2015) noted that pain following thoracotomy is of moderate-to-severe nature. Management of thoracotomy pain is a challenging task. Post-thoracotomy pain has acute effects in the post-operative period by affecting respiratory mechanics, which increases the morbidity. Poorly controlled thoracotomy pain in the acute phase may also lead to the development of a chronic pain syndrome. A young male patient underwent esophagectomy and esophago-gastric anastomosis for corrosive stricture of the esophagus. Epidural analgesia is standard of care for patients undergoing thoracotomy. Due to hypotension and fluid losses following surgery, he was maintained on intravenous sedato-analgesia during post-operative mechanical ventilation. The thoracic epidural catheter that was placed pre-operatively, had developed blockage during the hospital stay. However, during weaning from ventilation and sedation, he indicated severe pain in the thoracotomy incision. The pain was severe enough to impair tidal breathing. These researchers wanted to examine the efficacy of the serratus anterior plane (SAP) block in the management of thoracotomy pain. The usefulness of SAP block has been discussed in the management of pain of rib fractures and breast surgeries. Despite the hypothesis of its usefulness in causing anesthesia of the hemithorax, there are no available reports of clinical use for pain relief following thoracotomy. These investigators performed the SAP block under ultrasound (US) guidance and placed a catheter for continuous infusion of local anesthetics and opioid. The patient had significant pain relief following a single bolus of the drug. The infusion was started thereafter, which provided excellent analgesia and facilitated an uneventful recovery. The authors described the successful management of thoracotomy pain using the SAP block.

Ohgoshi et al (2015) noted that serratus-intercostal plane block (SIPB) is a novel US-guided thoracic wall nerve block reported recently. These researchers performed SIPB for peri-operative analgesia together with general anesthesia in patients undergoing partial mastectomy. They chose the patients with breast cancer of upper to lower lateral quadrant or subareolar region. Subjects received general anesthesia followed by US-guided SIPB. The needle was introduced in the mid-axillary line at the level of the fourth or fifth rib. Under continuous US guidance, these investigators injected 30-ml of ropivacaine 0.375 to 0.5 % between the serratus anterior and the external intercostal muscles. After the partial mastectomy, the area of sensory loss obtained by skin prick was extended from 5 to 6 as the number of intercostal spaces. Analgesic effect was obtained for 12 to 24 hours. The cephalad dermatomal paresthesia was T2. More than 20 patients received SIPB, and no one acquired the sensory loss at T1 of dermatomal distribution. The authors concluded that SIPB provided effective analgesia for breast surgery of upper to lower lateral quadrant and/or subareolar region. However, it should be administered with other additional analgesic agents when axillary dissection was performed, because sensory loss of T1 was difficult to achieve.

Khalil et al (2017) stated that thoracotomy is one of the most painful surgical procedures. In a prospective, randomized, observer-blinded, controlled study, these researchers examined the safety and effectiveness of US-guided SAPB compared with thoracic epidural analgesia (TEA) for controlling acute thoracotomy pain. The study was performed as a single-institution study in the National Cancer Institute, Cairo University, Egypt. All participants were cancer patients scheduled for thoracotomy. This trial was conducted from February to December 2015. A total of 40 patients scheduled for thoracotomy under general anesthesia were allocated randomly into 1 of 2 groups with 20 patients each; SAPB was performed before extubation with an injection of 30 ml of 0.25 % levobupivacaine followed by 5 ml/hour of 0.125 % levobupivacaine. In the TEA group, thoracic epidural catheters were inserted pre-operatively to be activated before extubation using a lower dose regimen to the SAPB group. Heart rate (HR), mean arterial pressure (MAP), and the visual analog pain score (VAS) measurements were recorded for 24 hours. Rescue analgesia using IV morphine, 0.1 ml/kg, was administered if the VAS was greater than 3. Compared with pre-operative values, the MAP in the SAPB group did not change significantly (p = 0.181), whereas it decreased significantly (p = 0.006) in the TEA group; VAS scores and the total dose of morphine consumed were comparable in the 2 groups. The authors concluded that SAPB appeared to be a safe and effective alternative for post-operative analgesia after thoracotomy. This study did not compare US-guidance versus no US-guidance.

Sir et al (2019) noted that SAPB has been used for pain management during the acute period of conditions affecting the thorax, such as post-thoracotomy recovery, rib fracture, and breast surgery recovery. These investigators reported the use of SAPB in post-traumatic chronic pain treatment. They e described a case of post-traumatic chronic intercostal neuralgia, in which successful pain relief was achieved via repeated injections of local anesthetic and steroid combinations in the serratus anterior plane under US-guidance. The authors concluded that this novel technique was easy to administer, reliable, and warrants further investigation with regard to its use for rehabilitation of patients who are suffering from post-traumatic chronic neuropathies of the chest wall.

Vig et al (2019) noted that post-thoracotomy pain is one of the most severe forms of post-operative pain. Anesthetists usually manage post-thoracotomy pain with an epidural or para-vertebral block. However, both of these techniques have their limitations; US-guided inter-fascial plane block like SAPB is a new concept and is proposed to provide analgesia to the hemithorax. These investigators reported their experience with 10 thoracotomy cases where this block was used as a post-operative analgesic technique. Patients undergoing pulmonary metastasectomy or lobectomy received US-guided SAPB between the serratus anterior and the external intercostal muscles with 0.25 % ropivacaine, and a catheter was inserted. Post-operatively, 0.125 % ropivacaine with fentanyl (1 ug/ml) was given as infusion at 5 to7 ml/hour. Other analgesics were paracetamol and diclofenac. Fentanyl infusion at 0.25 ug/kg/hour was the rescue analgesic if pain persisted; 4 out of 10 patients required fentanyl infusion. Uncontrolled pain in 2 of these patients was at the intercostal drain site; in the third patient, 2 ribs were resected; and in the fourth patient, there was poor drug spread and the catheter could not be placed in the desired plane due to poor muscle mass. The catheter was kept in-situ for a minimum of 48 hours to a maximum of 6 days after surgery. The authors concluded that SAPB could be an attractive option for post-thoracotomy analgesia.; further studies can take the help of the surgeon for catheter placement in the desired plane at the time of wound closure to ensure adequate drug spread.

In a prospective, randomized, single-blind study, Kaushal et al (2019) compared the relative efficacy of US-guided SAPB, pectoral nerves (Pecs) II block, and intercostal nerve block (ICNB) for the management of post-thoracotomy pain in pediatric cardiac surgery. This trial was conducted in a single-institution tertiary referral cardiac center, and comprised 108 children with congenital heart disease requiring surgery through a thoracotomy. Children were allocated randomly to 1 of the 3 groups: SAPB, Pecs II, or ICNB. All participants received 3 mg/kg of 0.2 % ropivacaine for US-guided block after induction of anesthesia. Post-operatively, IV paracetamol was used for multi-modal and fentanyl was used for rescue analgesia. A modified objective pain score (MOPS) was evaluated at 1, 2, 4, 6, 8, 10, and 12 hours post-extubation. The early mean MOPS at 1, 2, and 4 hours was similar in the 3 groups. The late mean MOPS was significantly lower in the SAPB group compared with that of the ICNB group (p < 0.001). The Pecs II group also had a lower MOPS compared with the ICNB group at 6, 8, and 10 hours (p < 0.001), but the MOPS was comparable at hour 12 (p = 0.301). The requirement for rescue fentanyl was significantly higher in ICNB group in contrast to the SAPB and Pecs II groups. The authors concluded that SAPB and Pecs II fascial plane blocks were equally efficacious in post-thoracotomy pain management compared with ICNB, but they had the additional benefit of being longer lasting and were as easily performed as the traditional ICNB. This study did not compare US-guidance versus no US-guidance.

Southgate and Herbst (2021) stated that approximately 10 % of injured patients presenting to the emergency department (ED) are found to have rib fractures. Rib fractures are associated with significant morbidity and mortality, especially in the elderly. Pulmonary complications, including pneumonia, often become apparent 2 to 3 days after injury, when respiratory function is compromised, secondary to pain. Thus, effective analgesia is an important component of rib fracture management; IV opioids are a mainstay of treatment but have side effects including respiratory depression, depressed cough reflex, and delirium in the elderly. The US-guided SAPB is an alternative that has become popular due to its efficacy, relative ease, and limited side-effect profile.

Wang et al (2019) stated that reports of post-operative pain treatment after uni-portal video-assisted thoracoscopic surgery (VATS) are limited. Thoracic para-vertebral block and SAPB have been described recently in pain management after thoracic surgery. A comparison between these 2 blocks for post-operative analgesia after uni-portal VATS has not been previously reported. In a retrospective, propensity-matched study, these researchers compared the analgesic benefits of SAPB and thoracic para-vertebral block after uni-portal VATS and examined the 2 block types for non-inferiority. From December 2015 to May 2018, a total of 636 relevant records of patients who underwent uni-portal VATS under general anesthesia alone or with the addition of SAPB or thoracic para-vertebral block performed pre-operatively were identified. A propensity-matched analysis incorporating pre-operative variables was used to compare the efficacy of post-operative analgesia in 3 groups. A total of 123 patients were identified for analysis. Propensity score matching resulted in 41 patients in each group. The VAS scores were significantly lower in the SAPB group and the thoracic para-vertebral block group than in the control group at the first, second, fourth, and sixth post-operative hours. Cumulative opioid consumption was significantly lower in the SAPB and thoracic para-vertebral block groups than in the control group at 6 hours (18.3 ± 3.1 mg, 18.7 ± 3.9 mg versus 21.5 ± 4.4 mg; p = 0.001) and 24 hours (43.4 ± 7.3 mg, 42.5 ± 7.7 mg versus 49.3 ± 8.8 mg; p < 0.001) post-operatively. The SAPB group was non-inferior to the thoracic para-vertebral block group on pain score and opioid consumption. The authors concluded that the findings of this study suggested that in patients undergoing uni-polar VATS, the addition of single-injection SAPB or thoracic para-vertebral block was associated with early analgesic benefits, including a reduction in post-operative opioid consumption and VAS score. These researchers stated that SAPB was as effective as thoracic para-vertebral block in reducing post-operative pain. Compared to thoracic para-vertebral block, SAPB is advantageous due to its relative ease of application. Moreover, they stated that although SAP block could be an effective therapeutic option for post-operative uni-polar VATS analgesia, further prospective, large-scale, randomized controlled trials are needed to examine the efficacy of and indications for SAPB.

In a randomized controlled trial, Reyad et al (2020) examined US-guided SAPB versus patient-controlled analgesia (PCA) on the emergence of post-thoracotomy pain syndrome (PTPS) after thoracotomies for thoracic tumors. This trial included 89 patients with chest malignancies, scheduled for thoracotomy were randomly allocated into 2 groups: Group A "PCA-group; n = 44" receiving patient-controlled analgesia; and group B "SAPB group; n = 45" where analgesia was provided by SAPB. The primary outcome measure was the assessment for the possible emergence of PTPS at 12 weeks. The secondary outcome measures were pain relief measured using VAS score. Quality of life (QOL) was assessed using Flanagan QOL Scale (QOLS) and activity level was assessed using Barthel Activity of daily living (ADL) score. At week 8, PTPS incidence was significantly (p = 0.037) higher in the PCA group (45 %) than in the SAPB group (24 %) with a relative risk (RR) of 1.38 and 95 % confidence interval (CI): 1.01 to 1.9; while the incidence of PTPS at week 12 was significantly (p = 0.035) higher in the PCA group (43 %) than in the SAPB group (22 %) with a RR of 2.38 and 95 % CI: 1.23 to 4.57. The need for pain therapy in PTPS patients was significantly lower in the SAPB group (17.7 %) than the PCA group (38.6 %) (p = 0.028) at week 12. Pain intensity: VAS-R and VAS-D (pain scores at rest and with activity, respectively) was comparable (p > 0.05) between both groups at 6, 12, 18 and 24 hours, however VAS was significantly higher in the PCA group at week 8 (p = 0.046) and week 12 (p = 0.032). Both groups were comparable regarding ADL and QOL scores (p > 0.05). The authors concluded that SAPB is assumed to be a good alternative for post-thoracotomy analgesia following thoracotomies. The current work hypothesized that SAPB for a week post-operatively, may reduce the emergence of PTPS and may reduce the demand for pain therapy in those patients.

Hanley et al (2020) stated that the deep SAPB is a promising novel regional anesthesia technique for blockade of the antero-lateral chest wall. Evidence for the efficacy of SAPB versus other analgesic techniques in thoracic surgery remains inadequate. In a randomized, double-blinded, single-center, non-inferiority study, these researchers compared US-guided continuous SAPB with a surgically placed continuous thoracic para-vertebral block (SPVB) technique in patients undergoing VATS. These investigators allocated 40 patients undergoing VATS to either SAPB or SPVB, with both groups receiving otherwise standardized treatment, including multi-modal analgesia. The primary outcome was 48-hour opioid consumption; secondary outcomes included numerical rating scale (NRS) for post-operative pain, patient-reported worst pain score (WPS) as well as functional measures (including mobilization distance and cough strength). A 48-hour opioid consumption for the SAPB group was non-inferior compared with SPVB. SAPB was associated with improved NRS pain scores at rest, with cough and with movement at 24 hours post-operatively (p = 0.007, p = 0.001 and p = 0.012, respectively). SAPB was also associated with a lower WPS (p = 0.008). Day 1 walking distance was improved in the SAPB group (p = 0.012), whereas the difference in cough strength did not reach statistical significance (p = 0.071). There was no difference in hemodynamics, opioid side effects, length of hospital stay or patient satisfaction between the 2 groups. The authors concluded that SAPB, as part of a multi-modal analgesia regimen, was non-inferior in terms of 48-hour opioid consumption compared to SPVB and was associated with improved functional measures in thoracic surgical patients.

Furthermore, an UpToDate review on "Thoracic nerve block techniques" (Rosenblatt and Lai, 2020b) states that "Thoracic interfascial plane blocks include the Pecs I, Pecs II, serratus plane (SP), transversus thoracic muscle plane (TTMP), and erector spinae (ESP) blocks. These blocks can be utilized for superficial and deep surgery in the chest wall and axillary regions (e.g., mastectomy, cosmetic breast surgery, chest tube placement, multiple rib fractures). We suggest the use of ultrasound guidance for TPVB and the interfascial plane blocks of the chest (Grade 2C), to increase the success rate and reduce complications". It also states that "The SP block is designed to anesthetize the thoracic intercostal nerves in order to provide analgesia for the lateral chest wall. Intercostal nerves from T2 to T9 are usually blocked. The SP block is a more posterior and lateral modification of the Pecs II block; they are not performed together. However, the Pecs I injection must be added to the SP block for breast reconstruction or surgery that violates the anterior chest wall, to block the medial and lateral pectoral nerves. The SP block is performed using ultrasound guidance".

Supraclavicular Nerve Block for Primary Regional Anesthesia During Surgeries / Post-Operative Pain Control

Karaman et al (2019) compared the effects of supraclavicular brachial plexus block (SCBPB) with ISBPB in terms of post-operative pain and quality of recovery after ASS. A total of 62 adult patients scheduled for ASS under general anesthesia were randomized into 2 groups to receive either ISBPB (IB group, n = 31) or SCBPB (SB group, n = 29) with 20-ml of 0.25 % bupivacaine under US guidance. Assessments included post-operative pain scores, additional analgesic requirement, timing of the first analgesic requirement, quality of recovery-40 (QoR-40) scores, block characteristics, and side effects. No significant differences were found between the 2 groups for pain scores (p = 0.34), timing of first analgesic requirement (p = 0.30), additional analgesic requirement (p = 0.34), or QoR-40 (p = 0.13) scores. The block characteristics regarding procedure time (p = 0.95), block failure, and onset time of sensory blockade (p = 0.33) were similar. Horner's syndrome occurred in 8 patients in the ISBPB group and 1 patient in the SCBPB group (p = 0.015). The authors concluded that this study showed that US-guided SCBPB was as effective as ISBPB in reducing post-operative pain and improving the quality of recovery for ASS.

Furthermore, an UpToDate review on "Upper extremity nerve blocks: Techniques" (Jeng and Rosenblatt, 2019b) states that "The supraclavicular approach blocks the brachial plexus at the level of the nerve trunks (upper, middle, and lower), where the nerves are packed closely together. Supraclavicular block provides a reliable, rapid onset and dense block for surgery of the distal two-thirds of the upper extremity, including those surgeries requiring an upper extremity tourniquet (e.g., hand surgery) … Ultrasound-guided supraclavicular block – We suggest the use of ultrasound guidance whenever a supraclavicular block is performed in order to minimize the chance of vascular puncture and pneumothorax. The ultrasound transducer is placed in a transverse position parallel to and just above the clavicle. The subclavian artery is identified by moving the transducer medially along the clavicle and directing the transducer toward the first rib. The brachial plexus at the level of the trunks and divisions appears as a "bundle of grapes" lateral to the subclavian artery. The lateral end of the transducer is often rotated slightly cephalad to visualize the brachial plexus in a more short-axis plane (perpendicular to its path). The needle is inserted in-plane from lateral to medial (parallel to the transducer), with the target being the junction of the subclavian artery, brachial plexus, and first rib ("corner pocket") and LA is injected to lift the brachial plexus off the first rib. Twenty to 30 mL of LA is injected, after negative aspiration for blood, in 5-mL increments, while looking for spread around the nerves. Most practitioners prefer a two-injection technique, with one-half of the LA deposited at the "corner pocket" and the other one-half deposited more superficially between trunks of the plexus or above the plexus. Injection should be stopped if the patient experiences pain or paresthesia".

An UpToDate review on “Overview of anesthesia” (Falk and Fleisher, 2021) states that “Peripheral nerve blocks are widely-used for surgical anesthesia, particularly for procedures in an upper or lower extremity. Ultrasound guidance with or without a nerve stimulator is typically used for placement of a needle or catheter”.

Transverse Abdominis Plane (TAP)-Block for the Management of Post-Operative Pain following Abdominal Surgery

Wang et al (2016) stated that US-guided ilio-inguinal/ilio-hypogastric (II/IH) nerve and transversus abdominis plane (TAP) blocks have been increasingly utilized in patients for peri-operative analgesia. In a meta-analysis, these researchers examined the clinical efficacy of US-guided II/IH nerve or TAP blocks for peri-operative analgesia in patients undergoing open inguinal surgery. A systematic search was conducted of 7 data-bases from the inception to March 5, 2015. Randomized controlled trials (RCTs) comparing the clinical efficacy of US-guided versus landmark-based techniques to perform II/IH nerve and TAP blocks in patients with open inguinal surgery were included. These investigators constructed random effects models to pool the standardized mean difference (SMD) for continuous outcomes and the odds ratio (OR) for dichotomized outcomes. Ultrasound-guided II/IH nerve or TAP blocks were associated with a reduced use of intra-operative additional analgesia and a significant reduction of pain scores during day-stay. The use of rescue drugs was also significantly lower in the US-guided group. The authors concluded that the use of US-guidance to perform an II/IH nerve or a TAP block was associated with improved peri-operative analgesia in patients following open inguinal surgery compared to landmark-based methods.

Park et al (2017) stated that TAP block has been used as a component of multi-modal analgesia after abdominal operation. These researchers introduced a new laparoscope-assisted TAP (LTAP) block technique using intra-peritoneal injection and compared its analgesic effect with that of an US-guided TAP (UTAP) block in terms of post-operative pain control. They carried out a prospective, randomized, single-blinded non-inferiority clinical trial with patients undergoing elective laparoscopic colectomy for colon cancer; 80 patients were randomly assigned (1:1 ratio) to the UTAP and LTAP groups. At the end of the operation, opioid consumption and numeric rating scores (NRS; 0 [no pain] to 10 [worst pain]) of pain were recorded at 2, 6, 24, and 48 hours post-operatively and were compared between the groups. The primary end-point was pain NRS during rest at 24 hours after operation. A total of 38 patients in the LTAP group and 35 patients in the UTAP group completed the study protocol. These investigators found no significant difference in mean ± SD pain NRS during rest at 24 hours between the LTAP group (3.90 ± 1.7) and the UTAP group (4.5 ± 1.9). The mean difference (MD) in pain NRS during rest at 24 hours was 0.57 (95 % confidence interval [CI]: -0.26 to 1.41). Because the lower boundary of a 95 % CI for the differences in pain NRS was greater than -1, non-inferiority was established. There was no significant difference between the groups in NRS pain during rest, NRS pain on movement, and post-operative morphine consumption during the 48 hours after operation. The authors concluded that these findings demonstrated that their new LTAP block technique was non-inferior to the US-guided technique in providing a TAP block after laparoscopic colorectal operation.

Kim et al (2017) stated that the concepts of enhanced recovery after surgery (ERAS) have steadily increased in usage, with benefits in patient outcomes and hospital length of stay (LOS). One important component of successful implementation of ERAS protocol is optimized pain control, via the multi-modal approach, which includes neuraxial or regional anesthesia techniques and reduction of opioid use as the primary analgesic; and TAP block is one such regional anesthesia technique, and it has been widely studied in abdominal surgery. These investigators conducted a literature search in Medline and PubMed, and reviewed the benefits of TAP blocks for colorectal surgery, both laparoscopic and open. They organized the data by surgery type, by method of TAP block performance, and by a comparison of TAP block to alternative analgesic techniques or to placebo. These researchers examined different end-points, such as post-operative pain, analgesic use, return of bowel function, and LOS. The majority of studies examined TAP blocks in the context of laparoscopic colorectal surgery, with many, but not all, demonstrating significantly less use of post-operative opioids in comparison to placebo, wound infiltration, and standard post-operative patient-controlled analgesia (PCA) with intravenous opioid administration. There was evidence that use of liposomal bupivacaine may be more effective than conventional long-acting local anesthetics. Non-inferiority of TAP infusions has been demonstrated, compared with continuous thoracic epidural infusions. The authors concluded that TAP blocks were easily performed, cost-effective, and an opioid-sparing adjunct for laparoscopic colorectal surgery, with minimal procedure-related morbidity. The evidence was in concordance with several of the goals of ERAS pathways. Moreover, this review did not mention the use of US-guidance for TAP block.

Doble et al (2018) stated that TAP blockade with long-acting anesthetic can be used during open ventral hernia repair (VHR) with posterior component separation (PCS). TAP block can be performed under US guidance (US-TAP) or under direct visualization (DV-TAP). These researchers hypothesized that US-TAP and DV-TAP provide equivalent post-operative analgesia following open VHR. They carried out a retrospective review of patients undergoing open VHR with PCS who received TAP blocks with 266-mg of liposomal bupivacaine. Data included demographics, co-morbidities, LOS, average post-operative day (POD) pain scores, and narcotic requirements (normalized to mg oral morphine). Statistical analysis utilized Student's t test and Fisher's exact test. A total of 39 patients were identified (22 DV-TAP). There were no differences between the groups with respect to demographics, co-morbidities, pre-operative pain medication usage (narcotic and non-narcotic) or herniorrhaphy-related data. The average POD0 pain score was lower for the DV-TAP group (2.35 versus 4.18; p = 0.019). Narcotic requirements on POD0 (48.0 versus 103.76 mg; p = 0.02), POD1 (128.45 versus 273.82 mg; p = 0.03), POD4 (54.29 versus 160.75 mg; p = 0.042), and during the complete hospitalization (408.52 versus 860.92 mg; p = 0.013) were lower in the DV-TAP group. There were no differences between initiation of diet or LOS. During the study, no changes were made to the VHR enhanced recovery pathway. The authors concluded that DV-TAP blocks appeared to provide superior analgesia in the immediate post-operative period. To achieve similar post-operative pain scores, patients in the US-TAP group required significantly more narcotic administration during their hospitalization. The study highlighted DV-TAP as a valuable addition to VHR recovery pathways.

Kakade and Wagh (2019) noted that TAP block is a fascial plane block providing post-operative analgesia after lower abdominal surgeries including Cesarean section. Conventionally, it is administered under US guidance or by blind technique. These researchers examined a novel trans-peritoneal surgical TAP block for providing safe and effective analgesia after Cesarean section through transverse incision. A total of 100 patients who fulfilled the inclusion criteria were included in the study after obtaining informed written consent. They were randomized in 2 groups: Group A with surgical TAP block and Group B without TAP block as control. Surgical TAP block was administered by trans-peritoneal route before the closure of peritoneum with 0.25 % bupivacaine (dose adjusted with weight of the patient), and VAS was assessed by a blind assessor. Time for rescue analgesia was noted and analyzed with the "2 independent sample t-test". The duration of post-operative analgesia in hours was significantly longer in the TAP block group compared with the control group (5.14 ± 1.63 versus 2.61 ± 0.89, p < 0.001). There was no reported complication of the surgical technique or any adverse effect of the used drug. The authors concluded that surgical TAP block via the trans-peritoneal route is a safe, easy and effective mode of providing post-operative analgesia after Cesarean section. This technique did not need any costly specialist equipment, overcame the technical limitations of US-guided TAP block and could be used in obese patients also. It had almost no side effects, and the technique could be easily mastered.

Vonu et al (2020) stated that there are a variety of regional nerve blocks that have been utilized in abdominoplasty procedures including transversus abdominis plane (TAP), intercostal, rectus sheath (RS), pararectus + II/IH, quadratus lumborum, and paravertebral blocks. No consensus exists regarding the most effective nerve block modality in optimizing post-procedural comfort levels. In a systematic review, these researchers examined the efficacy of the various abdominal nerve blocks used in abdominoplasty surgery, and drew attention to any modality that may be superior in regards to effectiveness and/or administration. Using PRISMA guidelines, a systematic review was performed to identify studies that have used regional nerve blocks in abdominoplasty procedures. Opioid consumption, pain scores, time to ambulation, time in the recovery room, and time to first analgesia request were extracted when available. A total of 191 articles were reviewed of which 8 met inclusion criteria. The nerve blocks represented included TAP, RS, pararectus + II/IH, intercostal, and quadratus lumborum. All modalities were effective in reducing opioid consumption except quadratus lumborum. The authors concluded that TAP, RS, pararectus + II/IH, and intercostal regional nerve blocks have been shown to optimize post-operative pain management in abdominoplasty procedures. When studied against one another, the existing literature suggested that TAP is more effective than RS and pararectus + II/IH. These researchers noted that when US guidance is unavailable, consideration should be given to TAP using the direct visualization approach.

Wong et al (2020) noted that TAP block is an important non-narcotic adjunct for post-operative pain control in abdominal surgery. Surgeons can use LTAP, however, direct comparisons to conventional UTAPs have been lacking. In a prospective, randomized, patient- and observer-blinded, parallel-arm, non-inferiority trial, these researchers examined if surgeon-placed LTAPs were non-inferior to anesthesia-placed UTAPs for post-operative pain control in laparoscopic colorectal surgery. This study was performed at a single tertiary academic center between 2016 and 2018 on adult patients undergoing laparoscopic colorectal surgery. Narcotic consumption and pain scores were compared for LTAP versus UTAP for 48 hours post-operatively. A total of 60 patients completed the trial (31 UTAP, 29 LTAP) of which 25 patients were women (15 UTAP, 10 LTAP) and the mean ages (SD) were 60.0 (13.6) and 61.5 (14.3) in the UTAP and LTAP groups, respectively. There was no significant difference in post-operative narcotic consumption between UTAP and LTAP at the time of PACU discharge (median inter-quartile range [IQR] milligrams of morphine, 1.8 [0 to 4.5] UTAP versus 0 [0 to 8.7] LTAP; p = 0.32), 6 hours post-operatively (5.4 [1.8 to 17.1] UTAP versus 3.6 [0 to 12.6] LTAP; p = 0.28), at 12 hours post-operatively (9.0 [3.6 to 29.4] UTAP versus 7.2 [0.9 to 22.5] LTAP; p = 0.51), at 24 hours post-operatively (9.0 [3.6 to 29.4] UTAP versus 7.2 [0.9 to 22.5] LTAP; p = 0.63), and 48 hours post-operatively (39.9 [7.5 to 70.2] UTAP versus 22.2 [7.5 to 63.8] LTAP; p = 0.41). Patient-reported pain scores as well as pre-, intra-, and post-operative course were similar between groups. Non-inferiority criteria were met at all post-operative time-points up to and including 24 hours but not at 48 hours. The authors concluded that surgeon-delivered LTAPs were safe, effective, and non-inferior to anesthesia-administered UTAPs in the immediate post-operative period. These investigators stated that this method (surgeon-placed LTAPs) should be considered in all patients undergoing laparoscopic colorectal surgery where an US-guided TAP block is planned.

Furthermore, an UpToDate review on "Abdominal nerve block techniques" (Rosenblatt and Lai, 2020a) states that "We perform TAP blocks with ultrasound guidance, though TAP block was first described using anatomic landmarks. TAP blocks can also be placed under direct vision by the surgeon during laparoscopy or laparotomy … We suggest using ultrasound guidance rather than anatomic landmarks to perform abdominal blocks (Grade 2C) to increase the success rate and reduce complications ".

Ultrasound Guidance: Experimental and Investigational Indications

Adductor Longus Tendon Injection

In a pilot study, Dallaudiere et al (2014) examined the potential therapeutic effect of intra-tendinous injection of platelet-rich plasma (PRP) under ultrasound (US) guidance to treat tendon tears and tendinosis with long-term follow-up. The study included 408 consecutive patients referred for treatment by PRP injection of tendinopathy in the upper (medial and lateral epicondylar tendons) and the lower (patellar, Achilles, hamstring and adductor longus, and peroneal tendons) limb who received a single intra-tendinous injection of PRP under US guidance. Clinical and US data were retrospectively collected for each anatomic compartment for upper and lower limbs before treatment (baseline) and 6 weeks after treatment. Late clinical data without US were collected until 32 months after the procedure (mean of 20.2 months). The McNemar test and regression model were used to compare clinical and US data. QuickDASH score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and residual US size of lesions were significantly lower after intra-tendinous injection of PRP under US guidance at 6 weeks and during long-term follow-up compared with baseline (p < 0.001 in upper and lower limb) independent of age, gender, and type of tendinopathy (p > 0.29). No clinical complication was reported during follow-up. The authors concluded that intra-tendinous injection of PRP under US guidance appeared to allow rapid tendon healing and was well-tolerated. Note: Per CPB 0784 - Blood and Adipose Product Injections for Selected Indications, we do not cover PRP injection for any indication.

Bisciotti et al (2021) stated that chronic adductor-related groin pain syndrome is a widely common problem for athletes in many sports activities that often drastically reduces player activity and performance. The 1st-line of treatment is conservative therapy. These investigators provided a systematic review regarding conservative treatment for chronic adductor-related groin pain syndrome present in literature today. Furthermore, they rendered a critical vision of the current state of the art of the considered topic. After screening 234 articles, a total of 19 studies following the inclusion criteria were included and summarized in this current systematic review and 7 different types of therapeutic interventions were described. Compression clothing therapy, manual therapy together with strengthening exercise and prolotherapy were the therapeutic interventions that showed both the greatest level of strength of evidence (Moderate) and grade of recommendation (D). The remaining 4 types of therapeutic interventions i.e., corticoid injection, PRP therapy, intra-tissue percutaneous electrolysis and pulse-dose radiofrequency, showed both lower levels of strength of evidence (conflicting) and grade of recommendation (C). The authors concluded that the literature available on the conservative treatment for chronic adductor-related groin pain syndrome was limited and characterized by a low-level of evidence; thus, their recommendation was to refer only to the few studies with higher level of evidence and at the same time to encourage further research in this area. The intervention showing the greater level of strength of evidence, and the greater grade of recommendation are compression clothing therapy, manual therapy and strengthening exercise, and prolotherapy. Other therapeutic interventions such as intra-tissue percutaneous electrolysis and pulse-dose radiofrequency appeared promising but require further studies to confirm their efficacy. This review did not mention US guidance for injections.

Furthermore, an UpToDate review on “Adductor muscle and tendon injury” (Patricios, 2021) does not mention ultrasound guidance as a management tool.

Ankle Bursa Injection

An UpToDate review on “Bursitis: An overview of clinical manifestations, diagnosis, and management” (Todd, 2021) states that “Imaging studies are typically not necessary, particularly in the case of superficial bursa where the signs of inflammation are demonstrated on the physical examination … Limited data suggest that ultrasound-guided injections of the subacromial bursa may be more effective than a "blind" injection; however, this was not validated in a large systematic review. As ultrasound guidance is not available in real time in many practices, we do not advocate that the use of ultrasound-guided injections is essential”.

Botulinum Toxin Injection for the Treatment of Cervical Dystonia

Hong et al (2012) noted that dysphagia is a common side effect after botulinum toxin (BTX) injections for cervical dystonia (CD), with an incidence of 10 to 40 %, depending upon the study and dose used. This study consisted of 5 pre-selected women who met criteria for CD and subsequent dysphagia after electromyography (EMG)-guided injections. Injections were performed with US imaging, and the effects on swallowing were examined. Separately, sternocleidomastoid (SCM) thickness in healthy controls and treated patients was measured. There were 34 episodes of dysphagia over 98 injection sessions using EMG guidance for a cumulative rate of 34.7 %. Using US plus EMG guidance, there was 0 % dysphagia across 27 injection sessions; SCM thickness was less than 1.1 cm. The authors concluded that US combined with EMG guidance eliminated recurrent dysphagia after BTX treatment, possibly by keeping the injectate within the SCM.

Huang et al (2015) examined the efficacy of US-guided local injection of BTX type A (BTX-A) treatment with orthopedic joint brace in patients with CD. A total of 105 patients with CD were selected and randomly divided into medication treatment group (A group), BTX treatment group under US guidance (B group) and BTX under US guidance combined with orthopedic joint brace treatment group (C group). Tsui scale and Spitzer quality of life (QOL) index was used to evaluate the spasm and QOL. The scores of Tsui scale and Spitzer QOL index were compared after US-guided local treatment for 1 month, 3 months and 6 months. The difference in Tsui and Spitzer scores before and after the treatment of oral medications were not statistically significant (p > 0.05). Whereas, the differences in Tsui and Spitzer scores before and after the treatment between local injection of BTX-A treatment group and orthopedic joint brace combined with BTX-A injection group were statistically significant (p < 0.05). Furthermore, the difference in Tsui and Spitzer scores of orthopedic joint brace combined with BTX-A injection group at 3 months, and 6 months were statistically significant compared to local injection of BTX-A treatment group (p < 0.05). The authors concluded that US-guided local injection of BTX-A combined with orthopedic brace could significantly reduce muscle tension and improve QOL. Moreover, US-guidance helped reduce BTX injection amount without affecting the efficacy and ensured that the medicine accurately reached to the site of action with a lower occurrence rate of adverse reactions.

In a systematic review, Grigoriu et al (2015) examined the impact of different injection-guiding techniques on the effectiveness of BTX-A for the treatment of focal spasticity and dystonia. Data sources included Medline via PubMed, Academic Search Premier, PASCAL, the Cochrane Library, Scopus, SpringerLink, Web of Science, EM Premium, and PsycINFO; 2 reviewers independently selected studies based on pre-determined inclusion criteria. Data relating to the aim were extracted. Methodological quality was graded independently by 2 reviewers using the Physiotherapy Evidence Database assessment scale for randomized controlled trials (RCTs) and the Downs and Black evaluation tool for non-RCTs. Level of evidence was determined using the modified Sackett scale. A total of 10 studies were included; 7 were randomized. There was strong evidence (level 1) that instrumented guiding (US, electrical stimulation [ES], EMG) was more effective than manual needle placement for the treatment of spasmodic torticollis, upper limb spasticity, and spastic equinus in patients with stroke, and spastic equinus in children with cerebral palsy (CP); 3 studies provided strong evidence (level 1) of similar effectiveness of US and ES for upper and lower limb spasticity in patients with stroke, and spastic equinus in children with CP, but there was poor evidence or no available evidence for EMG or other instrumented techniques. The authors concluded that these findings strongly recommended instrumented guidance of BTX-A injection for the treatment of spasticity in adults and children (ES or US), and of focal dystonia such as spasmodic torticollis (EMG). No specific recommendations can be made regarding the choice of instrumented guiding technique, except that US appeared to be more effective than ES for spastic equinus in adults with stroke.

Allison and Odderson (2016) reported a case of a young man with idiopathic CD who developed anterocollis (forward flexion of the neck) not responsive to prior scalene and SCM injections. To safely access the deeper cervical musculature, US was used in conjunction with EMG, to inject the longus colli muscles bilaterally. The patient responded well and had no complications. The longus colli has been reported to be injected using EMG, fluoroscopy, computed tomography (CT), and, less frequently, US. The authors proposed that US guidance is an excellent technique for BTX injection, especially for deep cervical muscles such as the longus colli.

Kutschenko et al (2020) examined the correlations of BTX therapy with dysphagia. These researchers studied a group of CD patients with optimized BTX therapy during a prolonged period of time to record their dysphagia frequency, severity and duration; they also assessed potential risk factors and attempted to avoid it by using US guidance for BTX applications. BTX therapy of 75 CD patients (23 men, 52 women, age of 60 ± 12 years, BTX total dose of 303.5 ± 101.5 uMU) was retrospectively analyzed for 1 year. BTX therapy was optimized before the observation period. Dysphagia was noticed by 1/5 of the patients. In those patients, it only occurred in about 1/3 of the injection series. It was never associated with a functional deficit and lasted several days to 2 weeks. It was not related to patient age or gender, BTX total dose, BTX dose in the SCM, BTX dose in the SCM and scalenii muscles, by BX therapy with bilateral SCM injections or BTX therapy with abobotulinumtoxinA. The authors concluded that US guidance was not able to prevent it. These researchers stated that further prospective studies are needed to examine the underlying dystonia associated swallowing abnormalities as a potentially predisposing factor.

Kim et al (2021) stated that US guidance may improve the accuracy of BTX injection, but studies of its potential for CD treatment are lacking. In an observational study, these researchers determined the accuracy of US-guided injection in the SCM; a total of 18 embalmed cadavers were used in this study. In total, 36 SCMs from 18 embalmed cadavers were examined. One physician performed US scans to divide each SCM into quarters and evaluated its cross-sectional area (CSA) and thickness at each of 3 meeting points between adjacent quarters. Under US guidance, another experienced physician injected methylene blue solution at 1 of the 3 points, using the in-plane technique (12 specimens/point; right SCM 3 ml, left SCM 5 ml). One anatomist dissected all cadavers and measured the distance of dye dispersion along the longitudinal axis of each muscle. Dispersion ratio was calculated as longitudinal dye dispersion divided by SCM length. Main outcome measures were SCM thickness and CSA; dye dispersion patterns (dispersion distance and dispersion ratio). SCM thickness and CSA were greatest at the middle injection point (mean ± SD 6.6 ± 2.0 mm and 1.4 ± 0.6 cm2 , respectively). All injections were successful, except in 1 case where the SCM was thin and the dye reached the omohyoid muscle. Mean longitudinal dye dispersion and dispersion ratio were significantly greater when the volume was 5 ml. There were no statistically significant differences in dispersion patterns among the 3 injection points. The authors concluded that US-guided intra-muscular injection could be performed with good accuracy in the SCM, as US could be used to evaluate SCM thickness and CSA. Moreover, these researchers stated that higher volumes of injection solution appeared to diffuse better, but further clinical studies are needed to determine optimal injection volume.

Furthermore, an UpToDate review on "Treatment of dystonia" (Comella, 2020) states that "there is no consensus regarding standard practices for BoNT injections, including dilution ratios for the different BoNT products, the dose per injection, the total dose per muscle, the number of injections at each site, or the methods of targeting injections (e.g., whether guided by vision, electromyography, or ultrasound). All of these parameters vary among practitioners and centers".

Botulinum Toxin Injection for the Treatment of Limb and Paraspinal Spasticity

In a prospective study, Py et al (2009) examined the effectiveness of injecting botulinum toxin A (BTX-A) into the lower limbs of children with CP, according to age, dose, dilution, injection site and needle placement technique (manual or US guidance). Any child with CP examined between May 2005 and May 2006 who needed BTX-A injections in the adductor, hamstring, gastrocnemius and/or soleus muscles could be included. A total of 54 children participated in the study, 30 of whom were injected under US guidance. The pre- and post-toxin evaluations were carried out through analytical clinical examination and the Gross Motor Function Measure (GMFM-88). These researchers found an overall clinical effectiveness for 51 % of the children. This effectiveness was significantly higher for children under 6 years old or over 12, especially when the doses were greater than 0.8 UI/kg per muscle of BTX, when the injected muscles were hamstrings or gastrocnemius, and when the injections were guided by US. Dilution had no effect on clinical effectiveness. Function after 1 month was better for 24 % of the children. This functional improvement was significantly better for children under 6 years old with the injections under US control. The authors concluded that the findings of this study confirmed that the effectiveness of BTX injections was higher in younger children, with injected doses higher than 0.8 UI/kg per muscle of BTX injections guided by US. These preliminary findings need to be validated by well-designed studies.

The authors stated that the main drawback of this study was that it was not a double-blind trial, which made interpreting the results less reliable. Also, the post-toxin evaluation took place before 1 month had passed also probably limited the significance of the results, as did the injection of low doses of the BTX per muscle for multi-site injections, in order to respect the cumulative dose of 6 UI/kg of Botox. Because both a radiologist and a re-education specialist need to be available at the same time, the muscle groups that would benefit the most from this technique (e.g., deep muscles? thin muscles?) need to be defined in order to use these specialists’ time more efficiently. This research should be continued with more sensitive methods for evaluating effectiveness and higher doses of BTX.

Rha et al (2014) stated that although the tibialis posterior is a potentially difficult muscle to locate for BTX injection because of its deep location, needle insertion is usually carried out using anatomic landmarks for guidance. Accordingly, the ultrasonographic anatomy of the lower leg was examined in hemiplegic children with spastic CP to improve the safety and the accuracy of needle placement into the tibialis posterior. A total of 25 subjects (2 years 2 months to 5 years 11 months; 12 boys, 13 girls; Gross Motor Function Classification System levels I to II) were recruited. B-mode, real-time US was carried out using a 5- to 12-MHz linear array transducer. During anterior and posterior approaches, safety window width (tibia to the neurovascular bundle) and depth (skin to the mid-point of the tibialis posterior) were measured at the upper third and at the mid-point of the tibia. For the anterior approach, the safety window width at the upper third of the tibia (mean [SD] of 0.63 [0.12] cm, range of 0.44 to 0.93 cm) was significantly larger than that at the mid-point (0.38 [0.09] cm, range from 0.22 to 0.59 cm, p < 0.05) of the affected leg. However, for the posterior approach, the safety window width at the mid-point (0.74 [0.23] cm, range from 0.21 to 1.18 cm) was significantly larger than that at the upper third of the tibia (0.48 [0.23] cm, range from 0.10 to 0.97 cm, p < 0.05) on the affected leg. The authors concluded that US guidance was a useful, safe, and accurate tool for needle insertion into the tibialis posterior. These investigators noted that considering the safety window width, the findings of this study suggested needle placement at the upper third point of the tibia for the anterior approach and at the mid-point for the posterior approach.

Wong et al (2015) noted that injections with BTX have been used off-label in treating cerebral palsy scoliosis (CPS). In a prospective, randomized, triple-blinded, cross-over study, these researchers reported both radiological and clinical improvement, whereas showing no side effects or complications in patients treated with either BTX-A or saline (NaCl). Subjects (brace-treated CPS between 2 and 18 years of age) were injected using US-guidance with either NaCl or BTX in selected spine muscles with 6 months intervals (block randomization, sealed envelope). Radiographs of the spine and clinical follow-up were captured before and 6 weeks after each injection. Primary outcome parameter was radiological change in Cobb angle, where a 7° change was regarded as an effect (1 SD). Radiological parameters were measured before and 6 weeks after treatment by 3 experienced doctors separately. Moreover, clinical results were evaluated by the pediatric quality of life score and systematic open questioning of the parents about the child's wellbeing. Subjects, researchers, and monitors were blinded during the trial. A total of 16 CP patients (GFMCS III-V) with CPS were consecutively included, whereas 6 patients were excluded. There were no drop-outs to follow-up, but 1 possible serious AE of pneumonia resulting in death was recorded and the study was terminated. No significant radiological or clinical changes were detected when compared with NaCl injections using Wilcoxon matched pair signed-rank test. The authors concluded that no positive radiological or clinical effects were demonstrated by this treatment, except for the parent's initial subjective but positive appraisal of the effect; however, the study was terminated due to 1 possible severe AE and scheduled numbers needed to treat (hence power) were not reached.

Schwabe (2016) stated that botulinum neurotoxin (BoNT) is one of the mainstays in the treatment of pediatric spasticity and dystonia. When considering initiation of BoNT treatment for spasticity, treatment goals and responses to prior conservative measures such as passive ROM exercises, splinting, and other medication trials should be reviewed. As a general rule, children should be engaged in therapy services around the time of the injections and have a robust home program in place. When managing spasticity in children with BoNT injections, the practitioner should be well versed in functional anatomy with specialized training in injection techniques. Localization techniques in addition to anatomical landmarks are recommended for improved efficacy and include limited EMG, electrical stimulation (ES), and/or US guidance. A follow-up visit for the purpose of re-assessment during the peak effect of the drug is advised. It is known that BoNT is effective at reducing spasticity and improving ROM, but it remains to be determined to what degree this translated into improved function, activity, and participation.

Calcaneal / Retrocalcaneal Bursa Injection

Brophy et al (1995) described the use of ultrasound (US) guidance for local steroid injection of the retrocalcaneal bursa and the tibialis posterior tendon sheath in patients with chronic inflammatory arthropathy. The authors concluded that US guidance may be the injection technique of choice but is especially indicated for patients with lesions unresponsive to injections guided by palpation.

Boesen et al (2006) described a case report of a 62-year old man with a 20-year history of tendon problems, who presented with a swollen and tender left Achilles tendon; US revealed a 2 x 1 x 0.9 cm intra-tendinous substance with acoustic shadowing. On a radiogram, ossification was found. Color Doppler activity was present in both the bursa and the tendon. A US-guided injection of 40-mg Depomedrol was applied into the retrocalcaneal bursa. On follow-up 2 months later, the patient had no symptoms and US showed total regression of Doppler activity. The ossification was unchanged. The authors concluded that US color Doppler may be recommended for guidance and monitoring of treatment.

Goldberg-Stein et al (2016) described a lateral fluoroscopically-guided retrocalcaneal bursa injection technique, reported patient outcomes at 1 to 4 weeks after steroid/anesthetic retrocalcaneal bursal therapeutic injection, and correlated pre-injection diagnostic heel US variables with improvement in patient pain scores. After internal review board (IRB) approval, fluoroscopically guided therapeutic retrocalcaneal bursa injections performed using a lateral approach were retrospectively reviewed. Pre-injection heel US results and pre- and post-injection patient visual analog scale (VAS) pain scores (scale 0 to 10) were recorded. The Wilcox matched-pair test compared pain scores, and Spearman's rho assessed for correlation between pain score changes and heel US results. A total of 32 injections were performed in 30 patients (25 females, 5 males; mean of 56.5 ± 9.3 years, range of 39 to 75 years; 21 left heels, 11 right heels) with technical success in 32 of 32 cases (100 %). Insertional Achilles tendon pathology and retrocalcaneal bursitis were present in 31 of 32 cases (97 %) and 16 of 32 cases (50 %), respectively. Median pre- and post-procedure pain scores were 8 (IQR 7, 10) and 1.75 (IQR 0, 6). A statistically significant decrease in pain score was observed following injection, with a median change of 4.75 (inter-quartile range [IQR] 3, 8; p < 0.001). Clinically significant response (greater than 50 % reduction in pain score) was present in 69 % (95 % confidence interval [CI]: 0.52 to 0.86; p < 0.001). No significant correlation was identified between a decrease in pain score and a sonographically abnormal Achilles tendon or retrocalcaneal bursa. The authors concluded that fluoroscopically-guided retrocalcaneal bursal steroid/anesthetic using a lateral approach was an effective technique. This technique yielded 100 % technical success and a clinically significant decrease in patient pain scores (p < 0.001).

An UpToDate review on “Bursitis: An overview of clinical manifestations, diagnosis, and management” (Todd, 2021) states that “Among patients with bursitis, obvious signs of swelling and inflammation may be evident upon physical exam only in superficial processes, such as olecranon, prepatellar, infrapatellar, or retrocalcaneal bursitis … we do not recommend the use of intralesional glucocorticoids in the treatment of the superficial forms of bursitis (olecranon, prepatellar, and retrocalcaneal) due to the risk of infectious complications, local tendon injury, draining sinus tract, or overlying skin atrophy … ”.

Furthermore, an UpToDate review on “Plantar fasciitis” (Buchbinder, 2021) states that “Overall, the diagnostic utility of ultrasound for plantar fasciitis is unproven as it may not add value over a clinical diagnosis and is not recommended for routine use … There is moderate-quality evidence that use of ultrasound to guide placement of the injection does not improve pain more than palpation-guided injections”.

Clavi-Pectoral Fascial Plane Block

Kukreja et al (2020) noted that the clavipectoral fascial plane block (CPB) is a novel regional anesthesia technique that has been used for clavicular fracture surgery. While the cutaneous innervation of the skin above the clavicle is well-known to be supplied by the supra-clavicular nerve of the superficial cervical plexus (SCP), the sensory innervation of the clavicle itself is somewhat controversial. Despite this controversy, it has been hypothesized that the CPB is an effective regional anesthesia technique for peri-operative analgesia since the terminal branches of many of the sensory nerves like suprascapular, subclavian, lateral pectoral, and long thoracic nerves pass through the plane between the clavipectoral fascia and the clavicle itself. These researchers presented the findings of 3 patients on the safety and effectiveness of CPB . Moreover, they noted that the decision to use the CPB alone or in addition to other techniques (SCP or interscalene block) may depend on the site of clavicle injury or variations in clavicular innervation. These investigators stated that larger, prospective studies are needed to further clarify the distribution of sensory blockade and the efficacy and safety of the CPB. Furthermore, they stated that until the controversy regarding sensory innervation of the clavicle is addressed or randomized controlled trials comparing SCP and brachial plexus blocks in clavicle surgery are carried out, a consensus on the regional anesthetic technique to be used for these surgeries may not be reached.

Costochondral Injection

Cho and Park (2019) stated that Tietze`s syndrome is an uncommon disease of unknown etiology that manifests as pain and tenderness of the para-sternal joints. To-date, however, there has been no report on US findings concerning swelling of the costochondral joint in Tietze`s syndrome. Moreover, there has been no research investigating images of US-guided corticosteroid injection, although corticosteroid injection is one of the most important treatments for Tietze`s syndrome. These investigators reported a case of Tietze`s syndrome where US images were used in the diagnostic and therapeutic process. A 70-year old man was examined for left chest pain that had lasted for several weeks. Physical examination at the authors’ clinic revealed a focal tenderness of the left third costochondral joint, and ultrasonography showed a swelling of the left third costochondral joint. Considering both the clinical and radiological examinations, the patient received a diagnosis of Tietze`s syndrome with costochondral joint swelling. Then, the patient agreed to an US-guided left third costochondral corticosteroid injection after receiving a detailed explanation of the disease and treatment. After receiving 3 US-guided corticosteroid injections, his chest pain subsided, and the swelling and tenderness also disappeared completely. The authors concluded that the findings of this case suggested that US was important in the diagnosis and treatment of Tietze`s syndrome.

Dorsal Scapular Nerve Block

Harmon and Hearty (2007) described a case report of using real-time, high-resolution ultrasound (US) guidance to facilitate blockade of the suprascapular nerve (SSN). They described a case report and technique for using a portable US scanner (38 mm broadband (13-6 MHz) linear array transducer (SonoSite Micromaxx SonoSite, Inc.) to guide SSN block. The subject was a 44-year old man who presented with severe, painful osteoarthritis with adhesive capsulitis of his right shoulder. The US transducer in a transverse orientation was placed over the scapular spine. Moving the transducer cephalad the suprascapular fossa was identified. While imaging the supraspinatus muscle and the bony fossa underneath, the US transducer was moved laterally (maintaining a transverse transducer orientation) to locate the suprascapular notch. The SSN was seen as a round hyperechoic structure at 4-cm depth beneath the transverse scapular ligament in the scapular notch. The nerve had an approximate diameter of 200 mm. Real-time imaging was used to direct injection in the scapular notch; US scanning confirmed local anesthetic spread. The patient's pain intensity decreased; shoulder movement and function improved. These improvements were maintained at 12 weeks. The authors concluded that US guidance did not expose patients and personnel to radiation. It was also less expensive than other imaging modalities. This technique has applications in both acute and chronic pain management.

Borglum et al (2011) presented a case with an US-guided (USG) placement of a perineural catheter beneath the transverse scapular ligament in the scapular notch to provide a continuous block of the SSN. The patient suffered from a severe and very painful adhesive capsulitis of the left shoulder secondary to an operation in the same shoulder conducted 20 weeks previously for impingement syndrome and a superior labral anterior-posterior tear. Following a new operation with capsular release, the placement of a continuous nerve block catheter subsequently allowed for nearly pain-free low impact passive and guided active mobilization by the performing physiotherapist for 3 consecutive weeks. This case and a short topical review on the use of SSN block in painful shoulder conditions highlighted the possibility of a USG continuous nerve block of the SSN as sufficient pain management in the immediate post-operative period following capsular release of the shoulder. Findings in other painful shoulder conditions and suggestions for future studies were discussed in the text.

Laumonerie et al (2019a) noted that a bone landmark-based approach (LBA) to the distal SSN (dSSN) block is an attractive "low-tech" method available to physicians with no advanced training in regional anesthesia or US guidance. The primary aim of this study was to validate the feasibility of an LBA to blockade of the dSSN by orthopedic surgeons using anatomic analysis. The secondary aim was to describe the anatomic features of the sensory branches of the dSSN. An LBA was performed in 15 cadaver shoulders by an orthopedic resident. Then, 10 ml of methylene blue-infused 0.75 % ropivacaine was injected around the dSSN; 2.5ml of red latex solution was also injected to identify the position of the needle tip. The division and distribution of the sensory branches that originate from the SSN were described. The median distance between the dSSN and the site of injection was 1.5 cm (0 to 4.5 cm). The most common injection site was at the proximal third of the scapular neck (n = 8); 15 dSSNs were stained proximal to the origin of the most proximal sensory branch. All 15 dSSNs gave off 3 sensory branches that innervated the posterior glenohumeral capsule, the subacromial bursa, and the coraco-clavicular and acromio-clavicular ligaments. The authors concluded that an LBA for anesthetic blockade of the dSSN by an orthopedic surgeon was a simple, reliable, and accurate method. Injection close to the suprascapular notch was recommended to involve the dSSN proximally and its 3 sensory branches.

Laumonerie et al (2019b) compared the accuracy of dSSN blockade performed with the use of US-guided regional anesthesia (USRA) versus with a LBA. A secondary aim was to describe the anatomic features of the sensory branches of the dSSN. USRA and LBA were performed in 15 shoulders each from 15 cadavers (total of 30 shoulders). Then, 10-ml of methylene blue-infused ropivacaine 0.75 % was injected into the dSSN. Simultaneously, 2.5-ml red latex solution was injected to identify the position of the needle tip. The division and distribution of the sensory branches originating from the SSN were described. The tip of the needle was identified at 1.3 cm (range of 0 to 5.2 cm) and 1.5 cm (range of 0 to 4.5 cm) with USRA and the LBA, respectively (p = 0.90). Staining diffused past the origin of the most proximal sensory branch in 27 cases. The most proximal sensory branch arose 2.5 cm from the suprascapular notch. Among the 3 failures that occurred in the USRA group, the sensory branches also failed to be marked. All 30 dSSNs gave off 3 sensory branches, which innervated the posterior glenohumeral capsule, the subacromial bursa, and the coraco-clavicular and acromio-clavicular ligaments. An LBA was as reliable and accurate as USG for anesthetic blockade of the dSSN. Marking of the SSN must be proximal to the suprascapular notch to involve the 3 sensory branches in the anesthetic blockade. The authors concluded that the present study demonstrated that a LBA to anesthetic blockade of the dSSN was accurate and can be performed by orthopedic surgeons lacking experience in USG anesthetic techniques.

Foot/Heel Injection for Adventitious Bursitis/Capsulitis

Srivastava and Aggarwal (2016) noted that ultrasound (US)-guided corticosteroid injection has been shown to be safe and effective for varied causes of plantar fasciitis; however, its use for Achilles tendinitis is controversial. These researchers examined the efficacy and changes in US findings at Achilles enthesitis after corticosteroid injection in patients with spondyloarthropathy (SpA). Patients with SpA with symptomatic Achilles enthesitis, refractory to 6 weeks of full-dose non-steroidal anti-inflammatory drugs (NSAIDs), were offered US-guided local corticosteroid injection. Injected entheses were examined by US (both B mode and power Doppler) at baseline and 6 weeks after injection. Standard OMERACT definitions were used to define enthesitis. Achilles tendon thickness of greater than 5.29 mm, 2 cm proximal to insertion in long axis, was considered thickened. A total of 27 symptomatic Achilles tendons (in 18 patients) were injected with 20-mg methylprednisolone under US guidance baseline, and 6-week follow-up US features were compared. All patients reported improvement in pain (VAS) in the affected tendon after injection (p < 0.0001). Simultaneously, improvement in local inflammatory changes were noted, in the form of significant reduction in tendon thickness (p < 0.0001), vascularity (p < 0.0001), peritendinous edema (p = 0.001), bursitis and bursal vascularity (p < 0.001 and < 0.0001, respectively). There was no change in bone erosions and enthesophyte. None of the patients had tendon rupture or other injection-related complications at 6 weeks of follow-up. The authors concluded that US-guided local corticosteroid injection was a safe and effective modality for refractory Achilles enthesitis in patients with SpA and led to reversion of acute changes at entheseal site. This was a small (n = 18 patients) study without a control group and addressed the use of US-guided injection for the treatment of Achilles tendinitis.

Wang et al (2019) stated that posterior heel pain is a common complaint that is often caused by overuse injuries. In such cases, the retrocalcaneal bursa is compressed and chafed repeatedly, leading to local inflammation. Sonography is a popular imaging tool used to study the pathology of soft tissues, and it can be used to assist in diagnosing bursitis because of its accuracy. These investigators reported an innovative method to treat retrocalcaneal bursitis under US guidance. A total of 10 patients with posterior heel pain for greater than 6 months who failed conservative treatment received this US-guided minimally invasive surgery. An endoscopic puncher and burr were inserted under US guidance via a stabbing wound, and the swollen retrocalcaneal bursa and bony prominence were resected. The patients were able to ambulate and undergo a rehabilitation program 2 weeks post-operatively. In the patients who underwent this US-guided minimally invasive surgery, both the average surgical time and average hospital stay were shorter than in those (n = 12) who underwent open surgery. In outcome rating assessment, the American Orthopedic Foot & Ankle Society (AOFAS) pain score and total AOFAS ankle-hindfoot score were improved in the US-guided minimally invasive surgery group compared to the open surgery group at 2 months post-operatively. Other advantages included lesser wound pain, shorter hospital stay, faster recovery time, and minimal blood loss. The authors concluded that US-guided surgery appeared to be a good option for the treatment of retrocalcaneal bursitis. This was a small (n = 10 patients) study without a control group and addressed the use of US-guided minimally invasive surgery for the treatment of retrocalcaneal bursitis.

Ganglion Cyst Injection of the Wrist / Wrist Injection

Breidahl and Adler (1996) demonstrated the use of ultrasound (US) guidance in confirming intralesional injection of corticosteroids and local anesthetic into symptomatic ganglia; and proposed potential advantages of this technique. A total of 10 patients (5 men, 5 women) underwent US-guided injection of a ganglion; 7 ganglia were near the wrist, 1 was adjacent to a finger interphalangeal joint and 2 were adjacent to the talus. All were injected with a 1:1 mixture of long-acting corticosteroid and local anesthetic, the actual volume being dependent on the size of the ganglion; 3 patients had a 2nd injection 9 to 18 months following the initial injection. In 4 patients the ganglia resolved completely. In 5 patients there was significant improvement, with a reduction in size of the ganglion and symptomatic relief. The authors concluded that US-guided injection insured intralesional deposition of corticosteroids and may provide an alternative to surgery in the management of ganglia.

Sofka et al (2001) examined the use of US guidance for intervention in the musculoskeletal system. All interventional musculoskeletal procedures using US guidance performed at the authors’ institution from July 1998 through November 1999 were reviewed. Examinations were performed using either a linear or curved phased array transducer, based on depth and local geometry. The choice of needle was likewise optimized for specific anatomic conditions. A total of 195 procedures were performed on 167 patients from July 1998 through November 1999; 31 procedures had magnetic resonance (MR) correlation within 6 months beforehand. Excluding large-joint aspirations and injections, these researchers found that 180 of the procedures were more readily performed using US than any other imaging modality. These included therapeutic injections into tendon sheaths (biceps, flexor digitorum longus, posterior tibial, and iliopsoas), Morton's neuromas, plantar fascia, wrist ganglia, and tarsal tunnel cysts; peritendinous hamstring injections; and synovial cyst and muscle biopsies. In all cases, the target of interest was identified easily with US, and needle position was documented readily. Also in all cases, aspiration or medication delivery to the site of interest was observed during real time and was documented on post-procedure images of the area. No significant complications (e.g., bleeding, infection, and neurovascular compromise) were encountered during or immediately after any procedure. The authors concluded that US is a readily available imaging modality useful for guiding interventional procedures in the musculoskeletal system. The ability to document exact needle placement in real time confirmed accurate placement of therapeutic injections, fluid aspiration, and soft tissue biopsies. Moreover, these researchers stated that although a formal clinical outcome study has yet to be performed, verbal communication with referring clinicians and patients has indicated an overall positive response.

In a retrospective study, Chen et al (2011) described the results of US examination in a series of patients with chronic wrist pain and defined the proportion of occult carpal ganglion in these patients. This trial included 57 patients with wrist pain consecutively referred for sonographic examination. The inclusion criteria for this study were a history of wrist pain longer than 3 months with no wrist trauma, and no palpable mass at the wrist. Ultrasound examination with a 10-MHz linear transducer was used to detect wrist pathology. A well-demarcated anechoic mass with posterior enhancement and without vascularity within the mass on sonography was defined as a ganglion cyst. A total of 33 of the 57 patients (58 %) were diagnosed by sonographic examination as having a ganglion in the wrist joint. The size of the ganglion demonstrated on sonographic imaging ranged from 2 x 5 mm to 10 x 9 mm on a longitudinal scan of the wrist (with a mean of 4 x 7 mm.). Surgical excision was performed in 12 patients who had ganglions diagnosed by sonographic examination; in all cases, the mucin content of the specimen was demonstrated; 8 patients underwent local aspiration followed by steroid injection under US guidance. The aspirated content was a jelly-like substance. In these 20 treated patients, symptoms of wrist pain improved after intervention. The authors concluded that the prevalence of occult carpal ganglion is common in chronic wrist pain patients; and high-resolution US examination facilitates early detection of occult carpal ganglion.

Smith et al (2011a) compared the accuracies of US-guided and palpation-guided scapho-trapezio-trapezoid (STT) joint injections in a cadaveric model. A clinician with 6 years of experience performing US-guided procedures injected 1.0 ml of a diluted latex solution into the STT joints of 20 un-embalmed cadaveric wrist specimens using a palmar approach. At a minimum of 24 hours after injection, an experienced clinician specializing in hand care completed palpation-guided injections in the same specimens using a dorsal approach and 1 ml of a different-colored latex. A fellowship-trained hand surgeon blinded to the injection technique then dissected each specimen to examine injection accuracy. Injections were graded as accurate if the colored latex was found in the STT joint, whereas inaccurate injections resulted in no latex being found in the joint. All US-guided injections were accurate (100 %; 95 % confidence interval [CI]: 81 % to 100 %), whereas only 80 % of palpation-guided injections were accurate (95 % CI: 61 % to 99 %); US-guided injections were significantly more accurate than palpation-guided injections, as determined by the ability to deliver latex into the joint (p < 0.05). The authors concluded that US guidance can be used to inject the STT joint with a high degree of accuracy and was more accurate than palpation guidance within the limits of this study design. Clinicians should consider using US guidance to carry out STT joint injections when precise intra-articular placement is needed. Moreover, these researchers stated that further clinical investigation examining the role of US-guided STT joint injections in the treatment of patients with radial wrist pain syndromes is needed.

Smith et al (2011b) stated that distal radioulnar joint (DRUJ) disorders are uncommon but important causes of ulnar-sided wrist pain and disability. Fluoroscopically-guided injections may be performed to diagnose or treat DRUJ-related pain or as part of a diagnostic arthrogram. Sonographic guidance may provide a favorable alternative to fluoroscopic guidance for distal DRUJ injections. These investigators described and validated a US-guided technique for DRUJ injections in an un-embalmed cadaveric model. An experienced clinician used US guidance to inject diluted colored latex into the DRUJs of 10 un-embalmed cadaveric specimens. Subsequent dissection by a fellowship-trained hand surgeon confirmed accurate injections in all 10 specimens; 2 cases of ulnocarpal flow, indicative of triangular fibrocartilage injury, were noted during injection and subsequently confirmed during dissection. The authors concluded that clinicians should consider using US guidance to perform DRUJ injections when clinically indicated. Moreover, these researchers stated that further research should examine the efficacy of US-guided DRUJ injections to treat patients with painful DRUJ syndromes or to evaluate the triangular fibrocartilage complex in patients with ulnar wrist pain syndromes.

Laurell et al (2012) noted that the wrist region is one of the most complex joints of the human body. It is prone to deformity and functional impairment in juvenile idiopathic arthritis (JIA), and is difficult to examine clinically. These researchers evaluated the role of Doppler US in diagnosis of synovitis, guidance of steroid injections, and follow-up examinations of the wrist in JIA. A total of 11 patients (median age of 12.5 years, range of 2 to 16), 15 wrists with clinically active arthritis were assessed clinically by US and color Doppler prior to and 1 and 4 weeks after US-guided steroid injection. US detected synovitis in the radio-carpal joints, the mid-carpal joints, and the tendon sheaths in 87 %, 53 % and 33 % of the wrists, respectively. Multiple compartments were involved in 67 %. US-guidance allowed accurate placement of steroid in all 21 injected compartments, with a low rate of subcutaneous atrophy. Synovial hypertrophy was normalized in 86 % of the wrists, hyperemia in 91 %, and clinically active arthritis in 80 %. The authors concluded that US enabled detection of synovial inflammation in compartments that were difficult to evaluate clinically and exact guidance of injections, and it was valuable for follow-up examinations. Normalization of synovitis was achieved in most cases, which supported the notion that US was an important tool in management of wrist involvement in JIA.

The authors stated that a drawback of this study was that the US assessments, were evaluated for accuracy by only 1 experienced musculoskeletal radiologist. In addition, the US examination protocol did not include the radio-ulnar joint, and hence these investigators could not rule out any synovitis in this compartment. Accordingly, in the future these researchers would use a revised and more appropriate scanning protocol for JIA that includes the radio-ulnar joint.

Leversedge et al (2016) stated that confirmation of pertinent anatomy and accurate needle placement for De Quervain injection may improve outcomes and limit complications. These researchers examined the accuracy of the 1st extensor compartment in regard to the following: (i) anatomic assessment, (ii) needle placement without imaging guidance, and (iii) US-guided injection with priority for the extensor pollicis brevis sub-compartment. Anatomic assessment and US-guided first extensor compartment injection was completed in 50 cadaver specimens. Initial needle placement was carried out without the guidance of US; its final position was evaluated with US. Then, using US, 1-ml of India ink was injected into the extensor pollicis brevis compartment. Open evaluation confirmed pertinent anatomy and injection accuracy. A sub-compartment of the 1st extensor compartment was identified in 27 of 50 wrists; 18 of 27 compartments were complete and 9 of 27 were incomplete, with US evaluation having an accuracy rate of 94 %. Accurate needle placement occurred in 26 of 50 wrists (52 %) when US was not used, but only 2 of 27 needles (7 %) were located within the extensor pollicis brevis sub-compartment. US-guided injection was 100 % accurate (50 out of 50) and extensor pollicis brevis injection was 96 % accurate (26 of 27) when 2 compartments were present. Minimal extravasation was identified in 6 of 50 wrists (12 %). The authors concluded that US-guided de Quervain injection improved injection accuracy through the visualization of compartmental anatomy and needle placement and may improve clinical outcomes by minimizing complications associated with extra-compartmental injection.

Milani and Lin (2018) noted that de Quervain tenosynovitis is a stenosing tenosynovitis of the 1st dorsal compartment of the wrist that could lead to painful functional impairment of the upper limb. This case presentation described a rare adverse effect of corticosteroid injection (CSI) involving local skin atrophy and hypo-pigmentation with proximal linear extension. In this case, hypo-pigmentation developed from the wrist to beyond the elbow after CSI with US guidance and targeted placement of the injectate in the extensor tendon sheath of the 1st dorsal compartment. Dermal complications of CSI were rare but notable and potentially disfiguring events that should be discussed with every patient during the informed consent process before soft tissue CSIs.

Kurkis et al (2019) stated that ganglion cysts are the most frequent soft tissue tumor encountered in the upper extremity (UE) and are commonly treated by aspiration or by surgical excision; and US is a promising addition to traditional aspiration, as it allows for visualization of the needle within the ganglion before aspiration. These researchers examined if ganglion cysts of the wrist were less likely to reoccur if they were aspirated under US guidance versus "blind" aspiration without the use of US guidance. They also studied if patient functionality change based on whether or not the cyst recurred? A total of 52 patients were successfully contacted and recurrence rates were compared between those whose cyst was treated with US-guided (n = 13) with those whose cyst was treated with blind aspiration (n = 39). Mean follow-up time was 2.9 years. Recurrence rates were 69 % (n = 9) and 74 % (n = 29) for the US-guided and blind aspiration groups, respectively (p-value: 0.73), showing no significant difference in recurrences of wrist ganglion between the 2 groups. A metric of functionality (Quick-DASH [Disabilities of the Arm, Shoulder, and Hand]) revealed worse outcomes in patients who experienced return of ganglion cyst after aspiration versus those who did not. The authors concluded that additional studies with improved sample sizes are needed to demonstrate the superiority of US-guided aspiration versus blind aspiration. Due to a high recurrence rate following aspiration (both US-guided and blinded), a lower threshold for surgical intervention is likely reasonable.

These researchers stated that future studies should look toward a randomized, prospective controlled trial to examine the possible benefit of US-guided aspiration of ganglion cysts of the wrist. Furthermore, this study could be expanded to examine the role of US in the management of ganglion cysts in other anatomical locations beyond the wrist. More research would also be useful in evaluating any morbidity associated with US-guided aspiration. Although it can be assumed that procedure-related morbidity and complications would likely be less with aspiration in comparison with open resection, it would be useful to examine if US guidance led to an improvement in treatment-associated morbidity compared with morbidity and complications associated with blind aspiration.

Furthermore, an UpToDate review on “Ganglion cysts of the wrist and hand” (De Geyser, 2021) states that “If available, ultrasonography is useful in the diagnosis of ganglia. Most ganglia have well-defined margins, thick walls, and acoustic enhancement. A solid-appearing ganglion, although unusual, may mimic a benign neoplasm”.

Gluteal Nerve Injection

In a cadaveric study, Finnoff et al (2008) compared the accuracy of ultrasound (US)-guided piriformis injections with fluoroscopically-guided contrast-controlled piriformis injections. A total of 20 piriformis muscles in 10 un-embalmed cadavers were injected with liquid latex using both fluoroscopically-guided contrast-controlled and US-guided injection techniques. All injections were performed by the same experienced individual. Two different colors of liquid latex were used to differentiate injection placement for each procedure, and the injection order was randomized. The gluteal regions were subsequently dissected by an individual blinded to the injection technique. Colored latex observed within the piriformis muscle, sheath, or both was considered an accurate injection; 19 of 20 US-guided injections (95 %) correctly placed the liquid latex within the piriformis muscle, whereas only 6 of the 20 fluoroscopically-guided contrast-controlled injections (30 %) were accurate (p = 0.001). The liquid latex in 13 of the 14 missed fluoroscopically-guided contrast-controlled piriformis injections and the single missed US-guided injection was found within the gluteus maximus muscle. In the single remaining missed fluoroscopically-guided contrast-controlled piriformis injection, the liquid latex was found within the sciatic nerve. The authors concluded that in this cadaveric model, US-guided piriformis injections were significantly more accurate than fluoroscopically-guided contrast-controlled injections. Despite the use of bony landmarks and contrast, most of the fluoroscopically attempted piriformis injections were placed superficially within the gluteus maximus. Clinicians performing piriformis injections should be aware of the potential pitfalls of fluoroscopically-guided contrast-controlled piriformis injections and consider using US guidance to ensure correct needle placement.

Smith et al (2012) described and validated US-guided techniques for injecting the obturator internus (OI) muscle or bursa using a cadaveric model. A single experienced operator completed 10 US-guided OI injections in 5 un-embalmed cadaveric pelvis specimens (4 female and 1 male, aged 71 to 89 years with body mass indices (BMI) of 15.5 to 24.2 kg/m2); 4 different techniques were used:

OI tendon sheath (4 injections),
OI intra-muscular (2 injections),
OI bursa trans-tendinous (2 injections), and
OI bursa short-axis (2 injections).

In each case, the operator injected 1.5-ml of diluted yellow latex using direct US guidance and a 22-G, 87.5-mm (3.5-in) needle; 72 hours later, study co-investigators dissected each specimen to examine injectate placement. All 10 OI region injections accurately placed latex into the primary target site; 2 of the 4 OI tendon sheath injections produced overflow into the underlying OI bursa. Both OI intra-muscular injections delivered 100 % of the latex within the OI. All 4 OI bursa injections (2 trans-tendinous and 2 short-axis) delivered 100 % of the latex into the OI bursa, with the exception that 1 OI bursa trans-tendinous injection produced minimal overflow into the OI itself. No injection resulted in injury to the sciatic nerve or gluteal arteries, and no injectate overflow occurred outside the confines of the OI or its bursa. The authors concluded that the results of this study showed that US-guided injections into the OI or its bursa were feasible and, thus, may play a role in the diagnosis and management of patients presenting with gluteal and "retro-trochanteric" pain syndromes.

Dillow et al (2013) stated that the para-sacral (PS) approach to sciatic nerve blockade has the potential for safe and effective use in children, but has never been studied in this population. Its potential advantages include increased posterior cutaneous nerve block reliability, potential for hip joint analgesia, and decreased nerve depth, making US guidance easier. These researchers examined the efficacy of an US-guided PS sciatic nerve block in children. A total of 19 patients, aged 1 to 16 years, scheduled for lower limb surgery with peripheral nerve blockade (PNB) were prospectively enrolled. A PS sciatic block was performed using both US guidance and nerve stimulation, and 0.5 ml/kg ropivacaine 0.2 % (maximum 20 ml) was administered. Patient demographics, the time to perform the block, the lowest intensity of nerve stimulation, evoked response, identification of gluteal arteries, and amount of narcotic given were recorded. Post-operatively, pain scores, block success or failure, block duration, and complications were recorded. The block was performed using the PS approach in 95 % of the cases. The success rate was 100 % in the PS sciatic blocks performed. The pain scores for all patients in the first post-surgical hour were 0, except 1 patient that had a pain score of 3 of 10 at 30 mins; his pain improved to 0 of 10 after administration of 1 dose of fentanyl and distraction techniques. The blocks lasted 17.3 ± 5.4 hours. No complications were identified. The authors concluded that the PS approach was an effective option for sciatic nerve blockade to provide post-operative pain relief in children having lower extremity surgery.

Gluteal Tendon Sheath Injections for Hip and/or Low Back Pain

In a single-case report, Chen et al (2017) described what these investigators believed was the 1st case of a patient with obturator internus tendinitis and bursitis successfully treated with a corticosteroid injection using a trans-tendinous lateral to medial approach. The patient presented with right gluteal pain not relieved by physical therapy or right hip and ischial bursa corticosteroid injections. Pelvic and lumbar spine MRIs and EMG/NCS findings were unremarkable. Physical examination demonstrated tenderness to palpation at the right middle lower gluteal region. Ultrasound (US) imaging with sono-palpation identified the maximal local tender point as the right obturator internus muscle and/or its underlying bursa. A 22-G 3.5-inch needle was inserted in-plane to the transducer and longitudinal to the obturator internus from a lateral to medial direction, an approach previously described in cadavers. The obturator internus tendon sheath and bursa were injected with 2.5-ml of 0.5 % lidocaine combined with 10-mg of triamcinolone. The patient reported immediate complete relief of pain with continued relief at 2 and 6 months post-injection. The authors concluded that this case report demonstrated an injection of the obturator internus tendon sheath and bursa using a trans-tendinous approach, which may be successful for treatment of patients presenting with persistent gluteal pain from obturator internus tendinitis and bursitis.

UpToDate reviews on “Treatment of acute low back pain” (Knight et al, 2021), and “Approach to the adult with unspecified hip pain” (Paoloni, 2021) do not mention gluteal tendon sheath injections as a management / therapeutic option.

Iliopsoas Bursa Injection

Blaichman et al (2020) noted that hip pain is a commonly reported primary symptom with many potential causes. The causal entity can remain elusive, even after clinical history review, physical examination, and diagnostic imaging. Although there are many options for definitive treatment, many of these procedures are invasive, are associated with risk of morbidity, and can be unsuccessful, with lengthy revision surgery required. Percutaneous musculoskeletal intervention is an attractive alternative to more invasive procedures and an indispensable tool for evaluating and managing hip pain. Ultrasonography (US) is an ideal modality for imaging guidance owing to its low cost, portability, lack of ionizing radiation, and capability for real-time visualization of soft-tissue and bone structures during intervention. These investigators evaluated both common and advanced US-guided procedures involving the pelvis and hip, including anesthetic and corticosteroid injections, percutaneous viscosupplementation, platelet-rich plasma (PRP) injection to promote tendon healing, and micro-wave ablation (MWA) for neurolysis. In addition, specific anatomic structures implicated in hip pain were discussed and included the hip joint, iliopsoas bursa, ilio-inguinal nerve, lateral femoral cutaneous nerve, greater trochanteric bursa, ilio-tibial band, ischio-gluteal bursa, hamstring tendon origin, piriformis muscle, and quadratus femoris muscle. The relevant US-depicted anatomy and principles underlying technically successful interventions also were discussed. Familiarity with these techniques could aid radiologists in assuming an important role in the care of patients with hip pain.

Furthermore, an UpToDate review on "Musculoskeletal ultrasonography: Guided injection and aspiration of joints and related structures" (Bruyn, 2020) does not mention iliopsoas bursa injection as an indication of US guidance.

Iliopsoas Tendon Injection

Sofka et al (2001) examined the use of ultrasonographic (US) guidance for intervention in the musculoskeletal system. All interventional musculoskeletal procedures using US guidance performed at the authors’ institution from July 1998 through November 1999 were reviewed. Examinations were performed using either a linear or curved phased array transducer, based on depth and local geometry. The choice of needle was likewise optimized for specific anatomic conditions. A total of 195 procedures were performed on 167 patients from July 1998 through November 1999; 31 procedures had magnetic resonance (MR) correlation within 6 months beforehand. Excluding large-joint aspirations and injections, these investigators found that 180 of the procedures were more readily performed using US than any other imaging modality. These included therapeutic injections into tendon sheaths (biceps, flexor digitorum longus, posterior tibial, and iliopsoas [peritendinous injection; n = 7]), Morton's neuromas, plantar fascia, wrist ganglia, and tarsal tunnel cysts; peritendinous hamstring injections; and synovial cyst and muscle biopsies. In all cases, the target of interest was identified easily with US, and needle position was documented readily. Also, in all cases, aspiration or medication delivery to the site of interest was observed during real-time and was documented on post-procedure images of the area. No significant complications (e.g., bleeding, infection, and neurovascular compromise) were encountered during or immediately after any procedure. The authors concluded that US is a readily available imaging modality useful for guiding interventional procedures in the musculoskeletal system. The ability to document exact needle placement in real-time confirmed accurate placement of therapeutic injections, fluid aspiration, and soft tissue biopsies.

Blaichman et al (2020) noted that hip pain is a commonly reported primary symptom with many potential causes. The causal entity can remain elusive, even after clinical history review, physical examination, and diagnostic imaging. Although there are many options for definitive treatment, many of these procedures are invasive, are associated with risk of morbidity, and can be unsuccessful, with lengthy revision surgery required. Percutaneous musculoskeletal intervention is an attractive alternative to more invasive procedures and an indispensable tool for evaluating and managing hip pain. Ultrasonography is an ideal modality for imaging guidance owing to its low cost, portability, lack of ionizing radiation, and capability for real-time visualization of soft-tissue and bone structures during intervention. These investigators reviewed both common and advanced US-guided procedures involving the pelvis and hip, including anesthetic and corticosteroid injections, percutaneous viscosupplementation, platelet-rich plasma (PRP) injection to promote tendon healing, and microwave ablation for neurolysis. In addition, specific anatomic structures implicated in hip pain were discussed and included the hip joint, iliopsoas bursa, ilio-inguinal nerve, lateral femoral cutaneous nerve, greater trochanteric bursa, iliotibial band, ischio-gluteal bursa, hamstring tendon origin, piriformis muscle, and quadratus femoris muscle. The relevant US-depicted anatomy and principles underlying technically successful interventions also were discussed. Familiarity with these techniques could aid radiologists in assuming an important role in the care of patients with hip pain.

Infiltration between the Popliteal Artery and Capsule of the Knee (IPACK) Block for Pain Control Following Anterior Cruciate Ligament (ACL) Repair

Thobhani et al (2017) stated that novel regional techniques, including the adductor canal block (ACB) and the local anesthetic infiltration between the popliteal artery and capsule of the knee (IPACK) block, provide an alternative approach for controlling pain following total knee arthroplasty (TKA). This study compared 3 regional techniques (femoral nerve catheter [FNC] block alone, FNC block with IPACK, and ACB with IPACK) on pain scores, opioid consumption, performance during physical therapy, and hospital length of stay (LOS) in patients undergoing TKA. All patients had a continuous peri-neural infusion, either FNC block or ACB. Patients in the IPACK block groups also received a single injection 30-ml IPACK block of 0.25 % ropivacaine. Pain scores and opioid consumption were recorded at post-anesthesia care unit (PACU) discharge and again at 8-hour intervals for 48 hours. Physical therapy performance was measured on post-operative days (POD) 1 and 2, and hospital LOS was recorded. These researchers found no significant differences in the 3 groups with regard to baseline patient demographics. Although these investigators observed no differences in pain scores between the 3 groups, opioid consumption was significantly reduced in the FNC with IPACK group. Physical therapy performance was significantly better on POD 1 in the ACB with IPACK group compared to the other 2 groups. Hospital LOS was significantly shorter in the ACB with IPACK group. The authors concluded that the findings of this study demonstrated that an IPACK block reduced opioid consumption by providing effective supplemental analgesia following TKA compared to the FNC-only technique; ACB with IPACK provided equivalent analgesia and improved physical therapy performance, allowing earlier hospital discharge.

The authors stated that this study had several drawbacks. Because these investigators identified no patients who would fit the criteria to receive ACB only during the study period, this study lacked a group that received ACB only, which would allow better analysis of the contribution of the IPACK block to an ACB. Because the ACB has gained attention by providing adequate analgesia to the anterior knee while minimizing motor impairment, addition of the IPACK block could improve posterior knee analgesia without sacrificing distal motor and sensory impairment. Comparing ACB only to ACB with IPACK block should be a goal for future research. Nevertheless, no prior publications had described the effects of the IPACK block for addressing posterior knee pain following TKA, and thus the opioid-sparing effect of the IPACK block when combined with the FNC block is a novel finding. Retrospective studies may suffer from assignment bias, possibly resulting in baseline differences between groups. However, the consecutive enrollment of patients in this study may have limited selection bias. In addition, this trial was a descriptive study of the benefits of a novel approach to regional analgesia for a common surgical procedure. An investigator needs to know a clinical delta, the difference in expectation that one regional technique provides compared to another technique, to calculate sample size. Because of the novel approach of this study, such information was not available, so this study could suffer from assignment bias. However, a strength of this study was that it allowed other investigator groups to validate these findings, and when needed, to use these findings to calculate a clinical delta for the appropriate sample size needed for a prospective RCT.

Sankineani et al (2018) noted that ACB is a peripheral nerve blockade technique that provides good pain control in patients undergoing TKA, which however does not relieve posterior knee pain. The recent technique of an US-guided IPACK has shown promising results in providing significant posterior knee analgesia without affecting the motor nerves. These researchers carried out a prospective study in 120 patients undergoing unilateral TKA. The initial 60 consecutive patients received ACB + IPACK (Group 1, n = 60), and the subsequent 60 patients received ACB alone (Group 2, n = 60). All patients were evaluated with visual analog scale (VAS) score for pain recorded at 8 hours, POD 1 and POD 2 after the surgery. The secondary outcome measures were range of movement (ROM) and ambulation distance. VAS score showed significantly (p < 0.005) better values in ACB + IPACK group compared to the ACB group. The mean ROM of knee and ambulation distance also showed significantly better values in ACB + IPACK group compared to the ACB group. The authors concluded that ACB + IPACK is a promising technique that offered improved pain management in the immediate post-operative period without affecting the motor function around the knee joint resulting in better ROM and ambulation compared to ACB alone. This was a relatively small study (n = 60 in the ACB + IPACK group); and its findings were confounded by the combined use of ACB and IPACK.

Kim et al (2019) stated that peri-articular injections (PAIs) are becoming a staple component of multi-modal joint pathways. Motor-sparing peripheral nerve blocks, such as the IPACK block and the ACB, may augment PAI in multi-modal analgesic pathways for TKA, but supporting literature remains rare. These researchers hypothesized that the addition of ACB and IPACK block to PAI would lower pain on ambulation on POD 1 compared to PAI alone. This triple-blinded, RCT included 86 patients undergoing unilateral TKA. Patients either received a PAI (control group, n = 43), or an IPACK block with an ACB and modified PAI (intervention group, n = 43). The primary outcome was pain on ambulation on POD 1; secondary outcomes included NRS pain scores, patient satisfaction, and opioid consumption. The intervention group reported significantly lower NRS pain scores on ambulation than the control group on POD 1 (difference in means [95 % CI]: -3.3 [-4.0 to -2.7]; p < 0.001). In addition, NRS pain scores on ambulation on POD 0 (-3.5 [-4.3 to -2.7]; p < 0.001) and POD 2 (-1.0 [-1.9 to -0.1]; p = 0.033) were significantly lower. Patients in the intervention group were more satisfied, had less opioid consumption (p = 0.005, PACU, p = 0.028, POD 0), less intravenous opioids (p < 0.001), and reduced need for intravenous PCA (p = 0.037). The authors concluded that the addition of IPACK block and ACB to PAI significantly improved analgesia and reduced opioid consumption after TKA compared to PAI alone. They stated that this study strongly supported IPACK block and ACB use within a multi-modal analgesic pathway. This was a relatively small study (n = 43 in the ACB + IPACK block + PAI group); and its findings were confounded by the combined use of ACB, IPACK and PAT.

Injection for Low Back Pain

In a systematic review, Hofmeister and colleagues (2019) evaluated the literature comparing US-guided injections to fluoroscopy-guided injections for the management of low back pain (LBP). Medline, Cochrane CENTRAL Register of Controlled Trials, Embase, and NHSEED were searched from 2007 to September 26, 2017. Inclusion criteria included: RCT design, compared US-guided and fluoroscopy-guided injections for LBP; dose and volume of medications injected were identical between trial arms, and reported original data. A total of 101 unique records were identified, and 21 studies were considered for full-text inclusion; 9 studies formed the final data set. Studies comparing US- and fluoroscopy-guided injections for LBP management reported no difference in pain relief, procedure time, number of needle passes, changes in disability indices, complications or AEs, post-procedure opioid consumption, or patient satisfaction. The authors concluded that fluoroscopic guidance of injections for the management of LBP was similar in efficacy to US guidance. These researchers stated that further study is needed to understand the exact role of US in image-guided injections.

Injection for Plantar Fasciitis

Li and co-workers (2014) noted that it is controversial whether US-guided injection of corticosteroid is superior to palpation-guided injection for plantar fasciitis (PF). In a meta-analysis, these investigators compared the effectiveness of US-guided and palpation-guided injection of corticosteroid for the treatment of PF. Databases (Medline, Cochrane library and Embase) and reference lists were searched from their establishment to August 30, 2013 for RCTs comparing US-guided with palpation-guided injection for PF. The Cochrane risk of bias (ROB) tool was used to assess the methodological quality. Outcome measurements were VAS, tenderness threshold (TT), heel tenderness index (HTI), response rate, plantar fascia thickness (PFT), hypo-echogenicity and heel pad thickness (HPT). The statistical analysis was performed with software RevMan 5.2 and Stata 12.0. When I2 was less than 50 %, the fixed-effects model was adopted. Otherwise the randomized-effects model was adopted. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was used to assess the quality of evidence. A total of 5 RCTs with 149 patients were identified and analyzed. Compared with palpation-guided injection, US-guided injection was superior with regard to VAS, TT, response rate, PFT and hypo-echogenicity. However, there was no statistical significance between the 2 groups for HPT and HTI. The authors concluded that US-guided injection of corticosteroid appeared to be more effective than palpation-guided injection; however, these findings need to be confirmed by further research with well-designed and large studies.

David and associates (2017) stated that plantar heel pain, commonly resulting from plantar fasciitis, often results in significant morbidity. Therapeutic options include non-steroidal anti-inflammatory drugs (NSAIDs), orthoses, physical therapy, physical agents (e.g., extracorporeal shock wave therapy (ESWT), laser) and invasive procedures including steroid injections. In a Cochrane review, these researchers examined the effects (benefits and harms) of injected corticosteroids for treating plantar heel pain in adults. They searched the Cochrane Bone, Joint and Muscle Trauma Group Specialized Register, the Cochrane Central Register of Controlled Trials (the Cochrane Library), Medline, Embase, CINAHL, clinical trials registries and conference proceedings; latest search was March 27, 2017; RCTs and quasi-RCTs of corticosteroid injections in the treatment of plantar heel pain in adults were eligible for inclusion. At least 2 review authors independently selected studies, assessed risk of bias and extracted data. These investigators calculated RRs for dichotomous outcomes and mean differences (MDs) for continuous outcome measures. They used a fixed-effect model unless heterogeneity was significant, when a random-effects model was considered. They assessed the overall quality of evidence for individual outcomes using the GRADE approach. These researchers included a total of 39 studies (36 RCTs and 3 quasi-RCTs) that involved a total of 2,492 adults. Most studies were small (median = 59 subjects). Subjects' mean ages ranged from 34 years to 59 years. When reported, most subjects had heel pain for several months. The trials were usually conducted in out-patient specialty clinics of tertiary care hospitals in 17 countries. Steroid injection was given with a local anesthetic agent in 34 trials. Follow-up was from 1 month to over 2 years. With one exception, trials were assessed at high risk of bias in 1or more domains, mostly relating to lack of blinding, including lack of confirmation of allocation concealment. With 2 exceptions, these researchers rated the available evidence as very low quality, implying in each case that they were "very uncertain about the estimate". The 39 trials covered 18 comparisons, with 6 of the 7 trials with 3 or 4 groups providing evidence towards 2 comparisons; 8 trials (724 subjects) compared steroid injection versus placebo or no treatment. Steroid injection may lead to lower heel pain VAS (0 to 100; higher scores = worse pain) in the short-term (less than 1 month) (MD -6.38, 9 5% CI: -11.13 to -1.64; 350 subjects; 5 studies; I² = 65 %; low quality evidence). Based on a minimal clinically significant difference (MCID) of 8 for average heel pain, the 95 % CI included a marginal clinical benefit. This potential benefit was diminished when data were restricted to 3 placebo-controlled trials. Steroid injection made no difference to average heel pain in the medium-term (1 to 6 months follow-up) (MD -3.47, 95 % CI: -8.43 to 1.48; 382 subjects; 6 studies; I² = 40 %; low quality evidence). There was very low quality evidence for no effect on function in the medium-term and for an absence of serious AES (219 subjects, 4 studies). No studies reported on other AEs, such as post-injection pain, and on return to previous activity. There was very low quality evidence for fewer treatment failures (defined variously as persistent heel pain at 8 weeks, steroid injection at 12 weeks, and unrelieved pain at 6 months) after steroid injection. The available evidence for other comparisons was rated as very low quality. These researchers were therefore very uncertain of the estimates for the relative effects on people with heel pain of steroids compared with other interventions in: Tibial nerve block with anesthetics (2 trials); orthoses (4 trials); oral NSAIDs (2 trials); and intensive physiotherapy (1 trial). Physical modalities: ESWT (5 trials); laser (2 trials); and radiation therapy (1 trial). Other invasive procedures: locally injectable NSAID (1 trial); platelet-rich plasma injections (PRP; 5 trials); autologous blood injections (2 trials); botulinum toxin injections (2 trials); cryo-preserved human amniotic membrane injection (1 trial); localized peppering with a needle (1 trial); dry needling (1 trial); and mini-scalpel needle release (1 trial). These investigators were also uncertain about the estimates from trials testing different techniques of local steroid injection: US-guided versus palpation-guided (5 trials); and scintigraphy-guided versus palpation-guided (1 trial). An exploratory analysis involving pooling data from 21 trials reporting on AEs revealed 2 ruptures of plantar fascia (reported in 1 trial) and 3 injection site infections (reported in 2 trials) in 699 participants allocated to steroid injection study arms; 5 trials reported a total of 27 subjects with less serious short-term AEs in the 699 subjects allocated steroid injection study arms. Reported treatments were analgesia, ice or both. Given the high risk of selective reporting for these outcomes and imprecision, this evidence was rated at very low quality. The authors found low quality evidence that local steroid injections compared with placebo or no treatment may slightly reduce heel pain up to 1month but not subsequently. The available evidence for other outcomes of this comparison was very low quality. Where available, the evidence from comparisons of steroid injections with other interventions used to treat heel pain and of different methods of guiding the injection was also very low quality. Although serious AES relating to steroid injection were rare, these were under-reported and a higher risk cannot be ruled out. The authors concluded that further research should focus on establishing the effects (benefits and harms) of injected steroids compared with placebo in typical clinical settings, subsequent to a course of unsuccessful conservative therapy. Ideally, this should be preceded by research, including patient involvement, aimed to obtain consensus on the priority questions for treating plantar heel pain.

Li and colleagues (2018) noted that the argument on whether ESWT and US-guided corticosteroid injections (CSIs) exert an equivalent pain control or which is the better treatment for PF in adults remains to be resolved. These researchers performed a meta-analysis to make a relatively more credible and overall assessment about which treatment method performs better pain control in treatment of PF in adults. From the inception to July 2018, the Embase, PubMed, Web of Science, and Cochrane Library electronic databases were searched for all relevant studies. Only RCTs focusing on comparing ESWT and CSI therapies in PF cases in adults were included. The primary outcome measure was VAS reduction, whereas the secondary outcomes included treatment success rate, recurrence rate, function scores, and AEs. A total of 9 RCTs involving 658 cases were included in this meta-analysis. The findings of this meta-analysis showed that high-intensity ESWT had superior pain relief and success rates relative to the CSI group within 3 months, but the ESWT with low intensity was slightly inferior to CSI for efficacy within 3 months. In addition, patients with CSI may tend to increase the need for the analgesic and more AES may be associated with the ESWT. However, the ESWT and CSI presented similar recurrent rate and functional outcomes. The authors concluded that this analysis showed that the pain relief and success rates were related to energy intensity levels, with the high-intensity ESWT had the highest probability of being the best treatment within 3 months, followed by US-guided CSI, and low-intensity ESWT. These researchers stated that more high-quality RCTs with long-term follow-up duration are needed to further compare the differences of US-guided CSI and ESWT for adults with PF.

Furthermore, an UpToDate review on "Plantar fasciitis" (Buchbinder, 2019) states that "There is moderate-quality evidence that use of ultrasound to guide placement of the injection does not improve pain more than palpation-guided injections".

Injection for Shoulder Pain

Rutten and colleagues (2007) stated that blind injection of the subacromial-subdeltoid bursa (SSB) for diagnostic purposes (Neer test) or therapeutic purposes (corticosteroid therapy) is frequently used. Poor response to previous blind injection or side effects may be due to a misplaced injection. It is assumed that US-guided injections are more accurate than blind injections. In a randomized study, these investigators compared the accuracy of blind injection to that of US-guided injection into the SSB. A total of 20 consecutive patients with impingement syndrome of the shoulder were randomized for blind or US-guided injection in the SSB. Injection was performed either by an experienced orthopedic surgeon or by an experienced musculoskeletal radiologist. A mixture of 1-ml methylprednisolone acetate, 4-ml prilocaine hydrochloride and 0.02-ml (0.01 mmol) gadolinium DTPA was injected. Immediately after injection, a 3D-gradient T1-weighted magnetic resonance imaging (MRI) of the shoulder was performed. The location of the injected fluid was independently assessed by 2 radiologists who were blinded as to the injection technique used. The accuracy of blind and US-guided injection was the same. The fluid was injected into the bursa in all cases. The authors concluded that blind injection into the SSB was as reliable as US-guided injection and could therefore be used in daily routine. These researchers noted that US-guided injections may offer a useful alternative in difficult cases, such as with changed anatomy post-operatively or when there is no effective clinical outcome.

In a prospective, randomized, double-blind study, Dogu and co-workers (2012) compared the accuracy of blind versus US-guided corticosteroid injections in subacromial impingement syndrome and examined the correlation between accuracy of the injection location and clinical outcome. A total of 46 patients with subacromial impingement syndrome were randomized for US-guided (group 1, n = 23) and blind corticosteroid injections (group 2, n = 23); MRI analysis was performed immediately after the injection. Changes in shoulder ROM, pain, and shoulder function were recorded. All patients were assessed before the injection and 6 weeks following the injection. Accurate injections were performed in 15 (65 %) group 1 patients and in 16 (70 %) group 2 patients. There was no statistically significant difference in the injection location accuracy between the 2 groups (p > 0.05). At the end of the sixth week, regardless of whether the injected mixture was found in the subacromial region or not, all of the patients showed improvements in all of the parameters evaluated (p < 0.05). The authors concluded that blind injections performed in the subacromial region by experienced individuals were reliably accurate and could therefore be given in daily routines. Corticosteroid injections in the subacromial region were very effective in improving the pain and functional status of patients with subacromial impingement syndrome during the short-term follow-up.

In a systematic review and meta-analysis, Wu and colleagues (2015) examined the effectiveness of US-guided (USG) versus blind (landmark-guided, LMG) corticosteroid SSB injection in adults with shoulder pain. Searches were performed on PubMed, Ovid Medline, Ovid Embase, Ovid Cochrane CENTRAL, Web of Science, Google Scholar, and Scopus from database inception through March 27, 2015. Studies included trials comparing USG versus LSG injections for the treatment of adults with SSB. Two reviewers independently performed data extraction and appraisal of the studies. The outcome measures collected were decreased VAS and Strengths and Difficulties Questionnaire (SDQ) scores, increased shoulder function scores and shoulder abduction ROM, and the effective rate at 6 weeks after injection. A total of 7 papers including 445 patients were reviewed; 224 received LMG injections and 221 received USG injections. There was a statistically significant difference in favor of USG for pain score [mean difference [MD] = 1.19, 95 % CI: 0.39 to 1.98, p = 0.003] and SDQ score [MD = 5.01, 95 % CI: 1.82, 8.19, p = 0.02] at 6 weeks after injection. Furthermore, there was a statistically significant difference between the groups, with greater improvement reported of shoulder function scores [SMD = 0.89, 95 % CI: 0.56 to 1.23, p < 0.001] and shoulder abduction ROM [MD 32.69, 95 % CI: 14.82 to 50.56, p < 0.001] in the USG group. More effective rate was also reported with USG group and the difference was statistically significant [risk ratio (RR) = 1.6, 95 % CI: 1.02 to 2.50, p = 0.04]. The authors concluded that US-guided corticosteroid injections potentially offered a significantly greater clinical improvement over blind SSB injections in adults with shoulder pain.

In a RCT, Cole and associates (2016) examined the clinical outcome of US-guided subacromial injections compared with blind subacromial injections for subacromial impingement syndrome. A total of 56 shoulders with subacromial impingement syndrome were randomized into 2 groups: 28 shoulders received a subacromial corticosteroid injection with US guidance (US group), and 28 shoulders received a subacromial corticosteroid injection without US guidance (blind group). The VAS for pain with overhead activities and the American Shoulder and Elbow Surgeons (ASES) score were obtained before the injection and at 6 weeks after the injection. The VAS score for pain with overhead activities decreased from 59 ± 5 mm (mean ± SEM) before the injection to 33 ± 6 mm at 6 weeks after the injection in the US group (p < 0.001) and from 63 ± 4 mm to 39 ± 6 mm, respectively, in the blind group (p < 0.001). The decrease in the VAS score was not significantly different between the groups (p > 0.999). The ASES score increased from 57 ± 2 before the injection to 68 ± 3 at 6 weeks after the injection in the US group (p < 0.01) and from 54 ± 3 before the injection to 65 ± 4 after the injection in the blind group (p < 0.01), with no significant difference between the groups (p = 0.7); 4 shoulders (14 %) in the US group and 6 shoulders (21 %) in the blind group eventually needed surgery (p = 0.7). The authors concluded that no significant differences were found in the clinical outcome when comparing US-guided subacromial injections to blind subacromial injections for subacromial impingement syndrome.

Intercostal Nerve Block

Shankar and Eastwood (2010) noted that steroid injection around the intercostal nerves (ICN) is one of the therapeutic options for intercostal neuralgia. The technique may be performed blindly, under fluoroscopic guidance (FSG) or with the use of USG. This study was a retrospective comparison of image guidance for intercostal steroid injections. After Institutional Review Board (IRB) approval, a retrospective review of all patient charts who received intercostal steroid injections from 2005 to 2009 was performed. A total of 39 blocks were performed in that period; 12 were USG blocks and 27 FSG blocks. The pre-procedure VAS and post-procedure VAS and the duration of pain relief were compared between the 2 techniques. The median change in the VAS for FSG and USG were -5.000 and -4.000, respectively, and duration of pain relief with a MD of 2 weeks (95 % CI: -4 to 7). There were 2 occasions of intravascular spread noticed with the FSG although this should not affect the study result as the needle was re-positioned and steroid injected only after contrast dye confirmation. The authors concluded that with similar change in VAS scores and duration of pain relief between the 2 guidance methods based on this retrospective study, both image guidance techniques may offer similar pain relief. The main drawbacks of this study were its retrospective design, small sample size (n = 12 for US guidance group), and the lack of a comparison group of "blind" injections by means of anatomic landmarks.

Bhatia et al (2013) stated that ICN injections are routinely performed under anatomic landmark or FSG for acute and chronic pain indications; US is being used increasingly to perform ICN injections, but there is lack of evidence to support the benefits of US over conventional techniques. These researchers compared guidance with US versus anatomic landmarks for accuracy and safety of ICN injections in cadavers in a 2-phase study that included evaluation of deposition of injected dye by dissection and spread of contrast on fluoroscopy. A cadaver experiment was performed to validate US as an imaging modality for ICN blocks. In the first phase of the study, 12 ICN injections with 2 different volumes of dye were performed in 1 cadaver using anatomic landmarks on one side and US-guidance on the other (6 injections on each side). The cadaver was then dissected to evaluate spread of the dye. The second phase of the study consisted of 74 ICN injections (37 US-guided and 37 using anatomic landmarks) of contrast dye in 6 non-embalmed cadavers followed by fluoroscopy to evaluate spread of the contrast dye. In the first phase of the study, the intercostal space was identified with US at all levels. Injection of 2-ml of dye was sufficient to ensure complete staining of the ICN for 5 of 6 US-guided injections; but anatomic landmark guidance resulted in correct injection at only 2 of 6 intercostal spaces. No intravascular injection was found on dissection with either of the guidance techniques. In the second phase of the study, US-guidance was associated with a higher rate of intercostal spread of 1 ml of contrast dye on fluoroscopy compared with anatomic landmarks guidance (97 % versus 70 %; p = 0.017). The authors concluded that US conferred higher accuracy and allowed use of lower volumes of injectate compared with anatomic landmarks as a guidance method for ICN injections in cadavers. They stated that US may be a viable alternative to anatomic landmarks as a guidance method for ICN injections. This was a cadaveric study.

Thallaj et al (2015) tested the hypothesis that identification and blockade of the inter-costo-brachial nerve (ICBN) can be achieved under US guidance using a small volume of local anesthetic. A total of 28 adult male volunteers were examined; ICBN blockade was performed using 1-ml of 2 % lidocaine under US guidance. A sensory map of the blocked area was developed relative to the medial aspect of the humeral head. The ICBN appeared as a hyper-echoic structure. The nerve diameter was 2.3 ± 0.28 mm, and the depth was 9 ± 0.28 mm. The measurements of the sensory-blocked area relative to the medial aspect of the humeral head were as follows: 6.3 ± 1.6 cm anteriorly; 6.2 ± 2.9 cm posteriorly; 9.4 ± 2.9 cm proximally; and 9.2 ± 4.4 cm distally; ICBN blockade using 1-ml of local anesthetic was successful in all cases. The authors concluded that the present study described the sonographic anatomical details of the ICBN and its sensory distribution to successfully perform selective US-guided ICBN blockade. These investigators stated that the volunteers in this study were all men and had a normal or low BMI; therefore, the observation might not be accurate for patients with a higher BMI or who are female. They recommended further studies to support and apply these findings to improve patient care.

In a pilot study, Wijayasinghe et al (2016) examined the feasibility of ICBN blockade and evaluated its effects on pain and sensory function in patients with persistent pain after breast cancer surgery (PPBCS). This prospective pilot study was performed in 2 parts: Part 1 determined the sono-anatomy of the ICBN; and part 2 examined effects of the US-guided ICBN blockade in patients with PPBCS. Part 1: 16 un-operated, pain-free BC patients underwent systematic US to establish the sono-anatomy of the ICBN. Part 2: 6 patients with PPBCS who had pain in the axilla and upper arm were recruited for the study. Summed pain intensity (SPI) scores and sensory function were measured before and 30 mins after the block was administered; SPI is a combined pain score of NRS at rest, movement, and 100 kPa pressure applied to the maximum point of pain using pressure algometry (max = 30). Sensory function was measured using quantitative sensory testing, which consisted of sensory mapping, thermal thresholds, supra-threshold heat pain perception as well as heat and pressure pain thresholds. The ICBN block was performed under US guidance and 10-ml 0.5 % bupivacaine was injected. Outcome measures were the ability to perform the ICBN block and its analgesic and sensory effects. Only the second intercostal space could be seen on US, which was adequate to perform the ICBN block. The mean difference in SPI was -9 NRS points (95 % CI: -14.1 to -3.9, p = 0.006). All patients had pre-existing areas of hypoesthesia that decreased in size in 4/6 patients after the block. The authors concluded that they had successfully managed to block the ICBN using US guidance and demonstrated an analgesic effect in patients in PPBCS. The authors stated that the main drawback of this pilot study was its small sample size (n= 6), but despite this, a statistically significant effect was observed. They suggested that a RCT is needed to ascertain the role of ICBN blockade in PPBCS.

Intra-Articular Steroid Injection for the Knee

An UpToDate review on "Intraarticular and soft tissue injections: What agent(s) to inject and how frequently?" (Roberts, 2019) does not mention the utility of imaging guidance (i.e., arthrogram/fluoroscopic/ultrasound).

Lateral Pericapsular Nerve Group (PENG) Nerve Block During Total Hip Arthroplasty

Jadon et al (2020) noted that pericapsular nerve group (PENG) block is a new ultrasound (US)-guided nerve block. It was used primarily to relieve pain in hip fracture; now, many new indications have been added. However, dependency on US guidance for this block limits its use where US facility is poor or unavailable. These researchers have suggested a landmark-based technique to increase the benefit of this novel nerve block. They carried out a feasibility study to examine the successful placement of block needle, clinical efficacy of the block and block-related complications. A total 10 patients (4 males and 6 females) with fracture hip and scheduled for hip surgery under spinal anesthesia were selected for the study. In 4 patients, US-guided PENG block using out-of-plane approach and in 6 patients landmark- based nerve stimulator guided block was given with 20 ml 0.25 % bupivacaine and 8 mg dexamethasone. Pain relief before and after 30 mins of block was evaluated by numeric rating scale (NRS) and comfort during spinal position was assessed by ease of spinal position score (EOSP). All 10 patients had successful block; NRS at rest was 6 (6 to 9) versus 2 (0 to 2) and on 15 degrees limb elevation was 8 (8 to 10) versus 3 (2 to 4). All patients could sit comfortably during spinal anesthesia and median (range) EOSP sore was 3 (2 to 3). No complication was observed. The authors concluded that landmark-based technique for PENG block is a feasible option and can be used safely where US facility is not available. Nerve stimulator guidance is essential to avoid inadvertent femoral nerve injury.

Morrison et al (2021) noted that the PENG block is a novel regional analgesia technique to reduce pain after hip surgery and hip fractures. These researchers examined current literature on the PENG block. They performed a scoping review using the Joanna Briggs Institute framework. All articles describing the use of PENG block as a regional analgesia and/or anesthesia technique for hip pain were considered eligible for inclusion. Ovid Medline, Embase, CINAHL, PubMed and Google Scholar were searched. Adult and pediatric studies were included. Excluded were articles not available in English language, not available in full-text, related to non-orthopedic indications such as soft tissue surgery, and pelvic or femoral shaft fractures. Database searches identified 345 articles, 20 of which could be included in the current review, with a combined patient number of 74. Included articles comprised case reports and case series only, describing 1 to 10 patients. In all studies, PENG block was described to provide adequate analgesia or anesthesia. Transient motor side effects occurred only when the local anesthetic was deposited in an unintended location (n = 2). The authors concluded that current evidence of using PENG block for hip surgery or hip pain is limited to case reports and case series only. They stated that the PENG block is a promising regional analgesia technique as an alternative to other regional nerve blocks such as femoral nerve block or iliac fascia nerve block. Moreover, these researchers stated that observational and experimental studies are needed to determine the safety and effectiveness of the PENG block.

Del Buono et al (2021) stated that the PENG block is a recently described US-guided technique for the blockade of the sensory nerve branches to the anterior hip joint capsule. It was described as an analgesic block for the acute pain management after hip fracture, while subsequent studies expanded the original indication. These investigators summarized the existing knowledge regarding the PENG block from the anatomical bases and provided an up-to-date description of the technique, applications and effects. They reviewed the following medical literature databases for publications on PENG block: PubMed, Google Scholar, Embase, and Web of science until August 31, 2020. Data regarding anatomy, indications, drugs and technique were also collected, reported and discussed. These researchers selected 57 relevant publications. Among them, 36 were case reports or case series and 12 publication were letters or correspondence; no randomized controlled trial (RCT) was identified. The main indication is the hip-related analgesia. The most commonly injected drug is a 20-ml long-acting local anesthetic. There are some cases of femoral and obturator nerve block, but no major complication such as hematoma/bleeding or needle-related organ injury has been reported yet. The authors concluded that the PENG block is a promising technique; RCTs of high methodological quality are needed to further elaborate the role of this block.

Lavage of the Shoulder Joint

Del Cura et al (2010) noted that ultrasonography (US) is the most appropriate tool for interventional procedures in the musculoskeletal system when the lesion is visible on US. Procedures performed under US guidance include: taking biopsies; draining abscesses; bursitis; hematomas or muscle tears; treating cystic lesions; diagnostic or therapeutic arthrocentesis; injecting substances into joints or lesions; aspirating calcium deposits and extracting foreign bodies. Although some of these procedures are often carried out without imaging guidance, US guidance improves their efficacy. Drainage can be performed with catheters or needles and makes it possible to avoid more aggressive treatments in most cases. Urokinase is useful for draining hematomas or fibrinous collections. Injecting corticoids is useful in the treatment of synovial cysts, Baker's cyst, tendinitis, and non-infective arthritis. Calcifying tendinitis of the shoulder can be treated effectively with percutaneous calcium lavage.

Sammour et al (2016) stated that musculo-skeletal US has evolved throughout the past 10 years. This procedure allows accurate corticosteroid injections guidance. Precision is much higher than the infiltration performed blindly or under fluoroscopy. These researchers described their technique in US-guided infiltration of the shoulder with an overview of the results. A total of 123 cases of US-guided infiltration of the shoulder were selected in the authors’ institution from July 2011 to June 2012. They were divided into sub-acromial sub-deltoid bursitis, biceps tenosynovitis, acromioclavicular osteoarthritis (OA), adhesive capsulitis and calcific tendinosis lavage and aspiration. The infiltration technique and the sonographic appearance in each condition were described. The rate of improvement was estimated between 70 % and 80 %. The authors concluded that US-guided infiltration provided an accurate and minimally invasive therapeutic option before any surgery. Recovery and socio-professional integration prove to be optimal and fast.

Furthermore, an UpToDate review on "Musculoskeletal ultrasound of the shoulder" (Finnoff, 2020) states that "Calcific tendinopathy appears as hyperechoic foci within the tendon. During the calcific phase, the calcification has significant posterior acoustic shadowing. The posterior acoustic shadowing becomes less prominent as the calcification progresses into the resorptive phase. Occasionally, hyperemia can be seen within the calcification or surrounding tendon tissue during the resorptive phase. During the resorptive phase, the calcification may be amenable to treatment via US-guided lavage and aspiration of the calcific material".

Lumbar Plexus Block with Hydrodissection

Lam et al (2017) stated that deep nerve hydrodissection uses fluid injection under pressure to separate nerves from areas of suspected fascial compression, which are increasingly viewed as potential perpetuating factors in recalcitrant neuropathic pain/complex regional pain. The usage of 5 % dextrose water (D5W) as a primary injectate for hydrodissection, with or without low-dose anesthetic, could limit anesthetic-related toxicity. An analgesic effect of D5W upon perineural injection in patients with chronic neuropathic pain has recently been described. These researchers described US-guided methods for hydrodissection of deep nerve structures in the upper torso, including the stellate ganglion, brachial plexus, cervical nerve roots, and paravertebral spaces. They retrospectively reviewed the outcomes of 100 hydrodissection treatments in 26 consecutive cases with a neuropathic pain duration of 16 ± 12.2 months and the mean Numeric Pain Rating Scale (NPRS; 0 to 10 pain level) of 8.3 ± 1.3. The mean percentage of analgesia during each treatment session involving D5W injection without anesthetic was 88.1 % ± 9.8 %. The pre-treatment NPRS score of 8.3 ± 1.3 improved to 1.9 ± 0.9 at 2 months after the last treatment. Patients received 3.8 ± 2.6 treatments over 9.7 ± 7.8 months from the first treatment to the 2-month post-treatment follow-up. Pain improvement exceeded 50 % in all cases and 75 % in half. The authors concluded that these findings confirmed the analgesic effect of D5W injection and suggested that hydrodissection using D5W provided cumulative pain reduction. These preliminary findings need to be validated by well-designed studies.

Median Nerve Block

Lewis et al (2015) noted that peripheral nerve blocks can be performed using US guidance. It is unclear if this method of nerve location has benefits over other existing methods. This review was originally published in 2009 and was updated in 2014. The objective of this Cochrane review was to examine if the use of US to guide peripheral nerve blockade has any advantages over other methods of peripheral nerve location. Specifically, these researchers examined if the use of US guidance improved success rates and effectiveness of regional anesthetic blocks, by increasing the number of blocks that were assessed as adequate, and reduced the complications, such as cardio-respiratory arrest, pneumothorax or vascular puncture, associated with the performance of regional anesthetic blocks. The authors concluded that there was evidence that peripheral nerve blocks performed by US guidance alone, or in combination with PNS, were superior in terms of improved sensory and motor block, reduced need for supplementation and fewer minor complications reported. Using US alone shortened performance time when compared with nerve stimulation, but when used in combination with PNS it increased performance time. The authors were unable to determine whether these findings reflect the use of US in experienced hands and it was beyond the scope of this review to consider the learning curve associated with peripheral nerve blocks by US technique compared with other methods.

In a Cochrane review, Walker et al (2019) examined if the use of US to guide peripheral nerve blockade has any advantages over other methods of peripheral nerve location. The authors concluded that in experienced hands, US provided at least as good success rates as other methods of peripheral nerve location. Individual studies have demonstrated that US may reduce complication rates and improve quality, performance time, and time to onset of blocks. Due to wide variations in study outcomes these researchers chose not to combine the studies in their analysis.

In a Cochrane review, Guay et al (2019) examined if US guidance offers any clinical advantage when neuraxial and peripheral nerve blocks are performed in children in terms of decreasing failure rate or the rate of complications. The authors concluded that US guidance for regional blockade in children probably decreased the risk of failed block. It increased the duration of the block and probably decreased pain scores at 1 hour after surgery; there may be little or no difference in the risks of some minor complications. These investigators stated that the 5 ongoing studies may alter the conclusions of the review once published and assessed.

Metatarsophalangeal and/or Metatarsal Cuneiform Joint Injection for the Treatment of Plantar Fibromatosis

Young et al (2018) noted that plantar fibromatosis (Ledderhose disease) is a rare, benign, hyper-proliferative fibrous tissue disorder resulting in the formation of nodules along the plantar fascia. This condition could be locally aggressive, and often results in pain, functional disability, and decreased QOL. Diagnosis is primarily clinical, but MRI and US are useful confirmatory adjuncts. Given the benign nature of this condition, treatment has historically involved symptomatic management. A multitude of conservative treatment strategies supported by varying levels of evidence have been described mostly in small-scale trials. These therapies include steroid injections, verapamil, radiation therapy, ESWT, tamoxifen, and collagenase. When conservative measures fail, surgical removal of fibromas and adjacent plantar fascia is often carried out, although recurrence is common. The authors concluded that given the benign nature of this condition, conservative therapies continue to be 1st-line options for symptomatic management; however, convincing, long-term research regarding their use does not yet exist. These investigators stated that further research is needed to determine an optimal treatment algorithm.

Jha et al (2020) stated that intra-articular injections have diagnostic and therapeutic roles in foot and ankle pathologies due to complex anatomy, small size, diverse bones, and joints with proximity in this region. Conventionally, these injections are performed using anatomical landmark technique and/or fluoroscopic guidance. The small joint space and needle size make the injection challenging. Fluoroscopy is not readily available in the clinical setting; thus, ultrasound (US)-guidance for injections is increasingly being used. These researchers compared the accuracy of intra-articular talo-navicular injections using the anatomical landmark technique versus the US-guided method. US guidance yielded superior results in intra-articular injections of the talo-navicular joint compared to injections using palpatory method guided by anatomical landmarks. The feet of 10 cadaveric specimens were held in neutral position by an assistant while a fellowship-trained foot-ankle orthopedic surgeon injected 2-cc of radiopaque dye using anatomical landmarks and palpation method in 5 specimens and under US guidance in the remaining 5. The needles were left in-situ in all specimens and their placement was confirmed fluoroscopically. In all 5 specimens injected under US guidance, the needle was found to be in the joint, whereas all 5 injected by palpation only were out of the joint, with 1 in the naviculo-cuneiform joint, showing US guidance to significantly increase the accuracy of intra-articular injections in the talo-navicular joint than palpatory method alone. The authors concluded that US-guided injections not only confirmed correct needle placement, but also delineated any tendon and/or joint pathology simultaneously. This was a small (n = 5 in the US-guided group) cadaveric study; these preliminary findings need to be validated in well-designed human studies.

Occipital Nerve Block

In a prospective, randomized, placebo-controlled, double-blind pilot trial, Palamar et al (2015) compared the effectiveness of US-guided greater occipital nerve block (GONB) using bupivacaine 0.5 % and placebo on clinical improvement in 23 patients with refractory migraine without aura (MWOA). Patients were randomly assigned to receive either GONB with local anesthetic (bupivacaine 0.5 % 1.5 ml) or GON injection with normal saline (0.9 % 1.5 ml). Ultrasound-guided GONB was carried out to more accurately locate the nerve. All procedures were performed using a 7- to 13-MHz high-resolution linear US transducer. The treatment group was comprised of 11 patients and the placebo group was comprised of 12 patients. The primary outcome measure was the change in the headache severity score during the 1-month post-intervention period. Headache severity was assessed with a VAS from 0 (no pain) to 10 (intense pain). In both groups, a decrease in headache intensity on the injection side was observed during the first post-injection week and continued until the second week. After the second week, the improvement continued in the treatment group, and the VAS score reached 0.97 at the end of the fourth week. In the placebo group after the second week, the VAS values increased again and nearly reached the pre-injection levels. The decrease in the monthly average pain intensity score on the injected side was statistically significant in the treatment group (p = 0.003), but not in the placebo group (p = 0.110). No statistically significant difference in the monthly average pain intensity score was observed on the un-injected side in either group (treatment group, p = 0.994; placebo group, p = 0.987). No serious side effect was observed after the treatment in either group. The authors concluded that US-guided GONB with bupivacaine for the treatment of migraine patients was a safe, simple, and effective technique without severe adverse effects. To increase the effectiveness of the injection, and to implement the isolated GONB, ultrasonography guidance could be suggested. The drawbacks of this pilot study include small sample size (n = 11 in the US-guided group) and short follow-up duration (1 month).

In a prospective open-label stud, Pingree et al (2017) examined the analgesic effects of an US-guided GONB at the level of C2, as the nerve courses superficially to the obliquus capitis inferior muscle. A total of 14 injections with US-guided GONBs at the level of C2 were performed on patients with a diagnosis of occipital neuralgia or cervicogenic headache; NRS pain scores were recorded pre-injection and at 30 mins, 2 weeks, and 4 weeks after injection. Anesthesia in the GON distribution was achieved for 86 % of patients at 30 mins post-injection. Compared with baseline, NRS scores decreased by a mean of 3.78 at 30 mins (p < 0.001), 2.64 at 2 weeks (p = 0.006), and 2.21 at 4 weeks (p = 0.01). There were no significant AEs reported during the study period. The authors concluded that their study demonstrated successful blockade of the GON at the level of C2 using a novel US-guided technique, and that significant reductions in pain scores were observed over the 4-week study period without AEs. The observations from this study provided preliminary data for future randomized trials involving patients with occipital neuralgia and cervicogenic headache.

Percutaneous Tenotomy of the Gluteus Medius Tendon for the Treatment of Hip Tendinopathy

Jacobson et al (2015) noted that percutaneous US-guided needle fenestration has been used to treat tendinopathy of the elbow, knee, and ankle with promising results. These researchers examined the clinical outcome of US-guided fenestration of tendons about the hip and pelvis. After Institutional Review Board (IRB) approval, a retrospective search of imaging reports from January 1, 2005, to June 30, 2011, was completed to identify patients treated with US-guided tendon fenestration about the hip or pelvis. Subsequent clinic notes were retrospectively reviewed to examine if the patient showed marked improvement, some improvement, no change, or worsening symptoms. The study group consisted of 22 tendons in 21 patients with an average age of 55.8 years (range of 26.7 to 77.0 years). The treated tendons included 11 gluteus medius (9 tendinosis and 2 partial tears), 2 gluteus minimus (both tendinosis), 8 hamstring (6 tendinosis and 2 partial tears), and 1 tensor fascia latae (tendinosis). The average interval to clinical follow-up was 70 days (range of 7 to 813 days). There was marked improvement in 45.5 % (10 of 22), some improvement in 36.4 % (8 of 22), no change in symptoms in 9.1 % (2 of 22), and worsening symptoms in 9.1 % (2 of 22). There were no patient variables (age, chronicity of symptoms, sex, tendon, tendinosis versus tear, prior physical therapy, and prior corticosteroid injection) that were significantly different between patients who improved and those who did not. There were no cases of a subsequent tendon tear or infection. The authors concluded that clinical follow-up following US-guided fenestration of the gluteus medius, gluteus minimus, proximal hamstring, and tensor fascia latae tendons showed that 82 % of patients had improvement in their symptoms. These researchers stated that further studies are needed to determine the long‐term effects of US‐guided tendon fenestration and to compare fenestration to other percutaneous tendon treatments.

The authors stated that this study had several drawbacks. Given the retrospective nature, they had to rely on dictated follow‐up visit notes from the referring clinicians to determine whether symptoms had improved. A prospective trial would allow more specific and objective assessment of patient symptoms at uniform intervals. In addition, imaging follow‐up was not obtained, so it was unclear whether changes on US imaging occurred after the tendon fenestration and whether such changes correlated with patient outcomes. Last, these investigators did not compare tendon fenestration to other treatments; a blinded randomized controlled trial (RCT) would be important to provide such information.

Jacobson et al (2016) compared US-guided percutaneous tendon fenestration to platelet-rich plasma (PRP) injection for treatment of greater trochanteric pain syndrome. After IRB approval was obtained, patients with symptoms of greater trochanteric pain syndrome and US findings of gluteal tendinosis or a partial tear (less than 50 % depth) were blinded and treated with US-guided fenestration or autologous PRP injection of the abnormal tendon. Pain scores were recorded at baseline, week 1, and week 2 after treatment. Retrospective clinic record review assessed patient symptoms. The study group consisted of 30 patients (24 female), of whom 50 % were treated with fenestration and 50 % were treated with PRP. The gluteus medius was treated in 73 % and 67 % in the fenestration and PRP groups, respectively. Tendinosis was present in all patients. In the fenestration group, mean pain scores were 32.4 at baseline, 16.8 at time point 1, and 15.2 at time point 2. In the PRP group, mean pain scores were 31.4 at baseline, 25.5 at time point 1, and 19.4 at time point 2. Retrospective follow-up showed significant pain score improvement from baseline to time points 1 and 2 (p < 0.0001); but no difference between treatment groups (p = 0.1623). There was 71 % and 79 % improvement at 92 days (mean) in the fenestration and PRP groups, respectively, with no significant difference between the treatments (p > 0.99). The authors concluded that the findings of this study showed that both US-guided tendon fenestration and PRP injection were effective for treatment of gluteal tendinosis, showing symptom improvement in both treatment groups. These researchers stated that future prospective RCTs with more long‐term and objective clinical assessment are needed to determine the clinical value of US-guided percutaneous tendon fenestration for the treatment of greater trochanteric pain syndrome.

The authors stated that this study had several drawbacks. First, long‐term symptom improvement was limited by retrospective assessment, with a somewhat short interval and a wide range of follow‐up durations. The sample size was limited (n = 15 for the US-guided percutaneous tendon fenestration group) because of budgetary constraints, and it remained possible that the effect size was not large enough to detect a difference between the treatment groups. Nonetheless, the results showed symptom improvement in the short-term and months after treatment. The limited retrospective follow‐up could be interpreted as a potential positive outcome if asymptomatic patients did not seek further treatment for their greater trochanter symptoms. Another drawback was that the PRP samples were not individually assessed for platelet count; however, the PRP preparation kit used was commercially available and was reported to concentrate platelets to 4 to 6 times that in whole blood. An additional drawback was that all patients had tendinosis, so it was unclear whether patients with tendon tears would respond in a different manner. One last limitation was that patient care after treatment was not controlled, which may affect longer‐term clinical outcomes.

Peritendon Injection for the Treatment of Achilles Tendinopathy

Chimenti et al (2020) stated that peripherally directed treatments (targeted exercise, surgery) can reduce, but not fully eliminate, pain for up to 40 % of patients with Achilles tendinopathy. In a mechanistic clinical trial, these researchers identified indicators of altered central processing in patients with Achilles tendinopathy compared to controls; and determined which indicators of altered central processing would persist after a local anesthetic injection in patients with Achilles tendinopathy. A total of 46 adults (23 with chronic Achilles tendinopathy, 23 matched controls) repeated a movement-evoked pain rating, motor performance assessment, pain psychology questionnaires, and quantitative sensory testing (QST). Participants with Achilles tendinopathy received a local anesthetic injection before repeat testing and controls did not. Mixed-effects analyses of variance examined the effects of group, time, and group by time. The Achilles tendinopathy group had movement-evoked pain, motor dysfunction, and higher pain psychological factors (pain catastrophizing, kinesiophobia) compared to controls (p < 0.05). The Achilles tendinopathy group did not have indicators of nociplastic pain with QST (p > 0.05). In those with Achilles tendinopathy, local anesthetic injection eliminated pain and normalized the observed deficits in heel-raise performance and pain catastrophizing (group-by-time effect, p < 0.01), but not in kinesiophobia (p = 0.45). Injection did not affect measures of nociplastic pain (p > 0.05). The authors concluded that individuals with Achilles tendinopathy had elevated pain psychological factors and motor dysfunction but no signs of nociplastic pain with QST. Removal of nociceptive input normalized movement-evoked pain and some indicators of altered central processing (motor dysfunction, pain catastrophizing), but not kinesiophobia. This was a relatively small (n = 23 in the Achilles tendinopathy group) study, and it did not address the use of ultrasound guidance for anesthetic injections.

An UpToDate review on “Overview of the management of overuse (persistent) tendinopathy” (Scott and Purdam, 2021) does not mention local anesthetics injection as a management / therapeutic option.

Furthermore, an UpToDate review on “Achilles tendinopathy and tendon rupture” (Maughan and Boggess, 2021) states that “High-volume injection -- This intervention (sometimes referred to as the Brisement procedure) involves injecting a high volume of fluid (typically consisting of isotonic saline, glucocorticoid, and local anesthetic), under ultrasound guidance, into the paratenon with the intent of reducing pain by disrupting abnormal blood vessels and peripheral nerves. Preliminary studies suggest possible benefit in patients with Achilles tendinopathy, including earlier return to sport, but further study is needed”.

Peroneal Tendon Sheath Injection

Muir e al (2011) described an ultrasound (US)-guided peroneal tendon sheath (PTS) injection technique and compared the accuracy of US-guided versus palpation-guided PTS injections in a cadaveric model. A total of 20 cadaveric lower limbs were injected with and without US guidance, using a different color of liquid latex for each injection technique. The injections were carried out by a single investigator in a randomized order. Cadaveric specimens were dissected 1 week later by a “blinded” investigator who graded injection accuracy on a 3-point scale (1 = accurate; 2 = partially accurate; and 3 = inaccurate); US-guided injections were 100 % (20 of 20) accurate whereas palpation-guided injections were 60 % (12 of 20) accurate (p = 0.008); 6 palpation-guided injections were partially accurate, and 2 were inaccurate; 2 of the partially accurate and both of the inaccurate injections were intra-tendinous. The authors concluded that in a cadaveric model, US-guided PTS injections were significantly more accurate than palpation-guided injections. When performing PTS injections, clinicians should consider US guidance to improve injection accuracy and minimize potential complications such as intra-tendinous injection. This was a small, cadaveric study; its findings need to be validated in well-designed human studies using human subjects

Platelet-Rich Plasma Injections in the Treatment of Hip Osteoarthritis

Ali and colleagues (2018) examined if US-guided platelet-rich plasma (PRP) injection has any role in improving clinical outcomes in patients with hip osteoarthritis (OA). These investigators carried out a search of the National Institute for Health and Care Excellence database using the Healthcare Databases Advanced Search tool. The PubMed database was also utilized to search the Medical Literature Analysis and Retrieval System Online, Excerpta Medica database, Cumulative Index of Nursing and Allied Health and Allied and Complimentary Medicine databases. The Preferred Reporting Items for Systematic Review and Meta-Analysis methodology guidance was employed and a quality assessment was performed using the Jadad score. A total of 3 randomized clinical trials met the inclusion criteria and were included for analysis. All 3 studies were of good quality based on the Jadad score. A total of 115 patients out of 254 received PRP injections under US guidance. The PRP recipient group included 61 men and 54 women aged 53 to 71 years. Outcome scores showed an improvement of symptoms and function maintained up to 12 months following PRP injection. The authors concluded that available evidence indicated that intra-articular PRP injections of the hip, performed under US guidance to treat hip OA, were well-tolerated and potentially effective in delivering long-term and clinically significant pain reduction and functional improvement in patients with hip OA. Moreover, these researchers stated that larger future trials including a placebo group are needed to further evaluate these promising findings.

Posterior Tibial Nerve Block for Plantar Fasciitis

Redborg et al (2009) noted that the tibial nerve provides the majority of sensation to the foot. Although multiple techniques have been described, there exists little evidence-based medicine evaluating different techniques for blocking the tibial nerve at the ankle. These researchers hypothesized that an ultrasound (US)-guided tibial nerve block at the ankle would prove more successful than a conventional approach based on surface landmarks. A total of 18 healthy volunteers were prospectively randomized into this controlled and blinded study. Each subject was placed prone, and 1 ankle was randomly assigned to receive either an US-guided tibial nerve block (group US) or a traditional landmark-based tibial nerve block (group LM). The subject's other ankle then received the alternate approach. All blocks were performed with 5-ml 3 % chloroprocaine. These investigators evaluated sensory and motor blocks. A successful block was defined as complete loss of sensation to both ice and pin-prick at 5 cutaneous sites. Secondary outcome variables included performance times, number of needle passes, participant satisfaction, and presence of any complications. At 30 mins, the block was complete in 72 % of participants in the US group as compared with 22 % in the LM group. At all times, the proportion of complete blocks was higher in the US group. Ultrasound-guided blocks took longer on average to perform than traditional blocks (159 versus 79 secs; p < 0.001). There were more needle re-directs in the US group, with 8 subjects requiring 3 or more re-directs versus 0 in the LM group. Subjects preferred the US block 78 % of the time (95 % confidence interval [CI]: 52 % to 95 %). The authors concluded that in healthy subjects, US guidance resulted in a more successful tibial nerve block at the ankle than did a traditional approach using surface landmarks. This was a small study (n = 18) carried out on healthy volunteers.

Shah et al (2020) stated that the use of US for peripheral nerve blocks has proven extremely useful for improving the accuracy and efficacy of many regional anesthetic techniques. There remain a few nerve blocks that have lagged behind in employing the assistance of US consistently, one of which is the ankle block. This block is commonly utilized for either surgical anesthesia or post-operative analgesia for a variety of foot and ankle procedures. These researchers compared the accuracy of traditional anatomical landmark-guided technique with an US-guided approach for ankle block by assessing the spread of injectate along the posterior tibial nerve (PTN) in cadaver models. A total of 10 below-knee cadaver specimens were used for this study; 5 were randomly chosen to undergo anatomical landmark-guided PTN blocks, and 5 were selected for US-guided PTN blocks. The anatomical landmark technique was performed by identifying the medial malleolus and Achilles tendon and inserting the needle (4 cm long, 21-G Braun Stimuplex) at the mid-point of the 2 structures, aiming toward the medial malleolus and advancing until bone was contacted. The US technique was performed with a linear probe identifying the medial malleolus and the PTN, with the needle subsequently advanced in-plane with a posterior to anterior trajectory until the tip was adjacent to the nerve. Each specimen was injected with 2-ml of acrylic dye. All the specimens were dissected following injection to determine which nerves had been successfully coated with dye. The PTN was successfully coated with dye in all 5 (100 %) US-guided blocks. In the anatomical landmark group, 2 (40 %) PTN were successfully coated with dye. Of the 3 unsuccessful attempts, 2 specimens were noted to have dye injected posterior to the PTN; dye was injected into the flexor digitorum longus tendon in 1. The authors concluded that the base of evidence has dramatically increased in recent years in support of the use of US in regional anesthesia. This study substantiated the superiority of US guidance for ankle block by demonstrating a 100 % success rate of delivering a simulated nerve block to the correct anatomic location.

Furthermore, an UpToDate on “Plantar fasciitis” (Buchbinder, 2021) does not mention the use of tibial nerve block as a therapeutic option for plantar fasciitis.

Subacromial Bursitis Injection

Lee et al (2011) noted that subacromial steroid injections are used as a treatment for subacromial bursitis (SB) or shoulder impingement syndrome (SIS). However, the steroid effect is relatively restricted to the short-term and repeated injections are frequently required, which contributes to unwanted side effects. As an alternative, botulinum toxin (BT) has recently been used for pain relief. These investigators examined the clinical effectiveness of BT type B and compared this with the effectiveness of steroids. A total of 61 patients diagnosed with SB or SIS were divided into 2 groups and treated with BT type B (BT group) and triamcinolone injection (TA group) under ultrasound (US) guidance, respectively. Numeric rating scale (NRS), active shoulder abduction angle, and the Korean version of the score on the Disability of Arm, Shoulder, and Hand (DASH) were measured before the treatment, and at 1 and 3 months after the treatment. Both groups obtained a significant improvement of NRS, DASH, and active shoulder abduction at 1- and 3-month follow-ups. BT group showed significantly better outcomes in terms of reduction of NRS and DASH at 3 months than TA group. BT group showed strong trend toward the larger degree of active shoulder abduction than the TA group at 3-month follow-up, as well. Whereas, no significant difference was found in NRS, DASH, and active shoulder abduction between the 2 groups at 1-month follow-up. The authors concluded that BT type B can be a useful strategy and has great potential for replacing steroids as a treatment for SB or SIS.

Molini et al (2012) noted that local injection of cortisone derivatives, sometimes combined with local anesthetics, is frequently administered in rheumatology as the treatment of choice in para-articular diseases or as an adjuvant to systemic therapy in the treatment of arthritis. One of the most frequent local corticosteroid injections administered in daily clinical practice by rheumatologists, orthopedic surgeons, physiatrists, sports medicine doctors and general practitioners is injection into the subacromial subdeltoid bursa in the treatment of bursitis and SIS. Before local corticosteroid injection is administered, it is important to identify possible contraindications and to examine the documentation provided by the patient. Absolute contraindications or those related to the procedure should be evaluated by the prescribing physician but also the physician performing the corticosteroid injection should evaluate possible contraindications to make sure that corticosteroid injection is feasible. These investigators described the US-guided local corticosteroid injection procedure with particular attention to the equipment required, the position of the patient and the examiner as well as the approach. The main advantage of US guidance during corticosteroid injection is the possibility to identify vascular structures, nerves and tendons situated in the needle path in order to avoid these structures and be sure to inject the drug into the appropriate location. When all rules were complied with and the corticosteroid injection was performed by an experienced physician, it was virtually painless and was carried out in just a few mins. This was a technical note; it did not compare US-guided injections with landmark-guided (blind) injections.

Hsieh et al (2013) stated that although US-guided subacromial injection has shown increased accuracy in needle placement, whether US-guided injection produces better clinical outcome is still controversial. These researchers compared the efficacy of subacromial corticosteroid injection under US guidance with palpation-guided subacromial injection in patients with chronic subacromial bursitis. Patients with chronic subacromial bursitis were randomized to a US-guided injection group and a palpation-guided injection group. Participants in each group were injected with a mixture of 0.5-ml dexamethasone suspension and 3-ml lidocaine into the subacromial bursa. The primary outcome measures were the visual analog scale (VAS) for pain and active and passive ranges of motion (ROM) of the affected shoulder. Secondary outcome measures were the Shoulder Pain and Disability Index (SPADI), the Shoulder Disability Questionnaire (SDQ), and the 36-item Short-Form Health Survey (SF-36). The primary outcome measures were evaluated before, immediately, 1 week, and 1 month after the injection; the secondary outcome measures were evaluated before, 1 week, and 1 month after the injection. Of the 145 subjects screened, 46 in each group completed the study. Significantly greater improvement in passive shoulder abduction and in physical functioning and vitality scores on the SF-36 were observed in the US-guided group. The pre- and post-injection within-group comparison revealed significant improvement in the VAS for pain and ROM, as well as in SPADI, SDQ, and SF-36 scores, in both groups. The authors concluded that the findings of this study demonstrated that subacromial corticosteroid injection, either with the palpation-guided method or under US guidance, was effective in reducing pain, increasing ROM, and improving SDQ, SPADI, and SF-36 scores in patients with chronic SAB. Furthermore, US-guided injection technique yielded significant improvement in shoulder passive abduction and some items of the SF-36 compared with the blind injection technique. In a clinic without a US machine, these investigators suggested palpation-guided injection of corticosteroid into the subacromial bursa for patients with chronic SAB; however, if palpation-guided injection failed, or a US machine is available, injection under US guidance is recommended.

The authors stated that this study had several drawbacks. First, they only performed follow-up assessments 1 month after the treatment; thus, the long-term effects of the treatments were unknown. Second, these researchers did not include an untreated control group for ethical and practical reasons. However, because most of the subjects had experienced shoulder pain for longer than 3 months without signs of spontaneous improvement, these investigators believed spontaneous recovery in a short period was unlikely. Third, these researchers did not use MRI to screen the patients; therefore, some labral lesions may have been missed in the sonography and plain x-ray of the shoulder. Fourth, even diagnostic block with local anesthetics for confirmation of SAB was not 100 % accurate, the spread of local anesthetics to other tissues (e.g., rotator cuff or ligaments), could not be excluded (but rotator cuff lesion could have been excluded during physical examination or ultrasonography).

Xiao et al (2017) stated that adhesive capsulitis (AC) is a self-limiting condition in a majority of patients and is often treated non-operatively. However, symptoms may take 2 to 3 years to resolve fully. A small, but significant, portion of patients require surgical intervention. In a systematic review, these investigators examined the efficacy of corticosteroid injections for the treatment of AC. They carried out a review of articles indexed by the U.S. National Library of Medicine (NLM) by querying the PubMed data-base for studies involving patients with AC, frozen shoulder, stiff shoulder, or painful shoulder. Articles that included corticosteroids, glucocorticoids, steroids, and injections were included. Corticosteroid injections provide significant symptom relief for 2 to 24 weeks. Injections can be performed intra-articularly or into the subacromial space. Evidence suggested that a 20-mg dose of triamcinolone may be as effective as a 40-mg injection; however, it remained unclear whether image-guided injections produced a clinically significant difference in outcomes when compared with landmark-guided (blind) injections. Corticosteroids may be less beneficial for diabetic patients. Patients using protease inhibitors (anti-retroviral therapy) should not receive triamcinolone because the drug-drug interaction may result in iatrogenic Cushing syndrome. The authors concluded that corticosteroid injections for AC demonstrated short-term efficacy; however, it may not provide a long-term benefit. Moreover, these researchers stated that more high quality, prospective studies are needed to determine whether corticosteroid injections using US guidance significantly improve outcomes.

Furthermore, an UpToDate review on “Bursitis: An overview of clinical manifestations, diagnosis, and management” (Todd, 2021) states that “Limited data suggest that ultrasound-guided injections of the subacromial bursa may be more effective than a "blind" injection; however, this was not validated in a large systematic review. As ultrasound guidance is not available in real time in many practices, we do not advocate that the use of ultrasound-guided injections is essential”.

Subtalar Joint Injection

Reach et al (2009) stated that US is an emerging imaging modality that affords dynamic, real-time, cost-effective and surgeon controlled visualization of the foot and ankle. These researchers evaluated the accuracy of US-guided injections for common injection sites in the foot and ankle. In 10 fresh cadaver feet, US guidance was utilized to inject a methylene blue-saline mixture into the first metatarsophalangeal (MTP) joint, the second MTP joint, the tibio-talar joint, the Achilles peritendinous space, the flexor hallucis longus sheath, the posterior tibial tendon sheath, and the subtalar joint. Dissection was then undertaken to assess injection accuracy; US guidance allowed the avoidance of intervening neurovascular and tendinous structures; US-guided MTP, ankle, Achilles, PTT and FHL peritendinous injections were 100 % accurate; US-guided subtalar injection was 90 % accurate. The authors concluded that US appeared to be a highly accurate method of localizing injections into a variety of locations in the foot and ankle. These investigators stated that US’s ability to display soft-tissue structures may be an advantage over blind injection and fluoroscopic injection techniques. This was a cadaveric study.

Khosla et al (2009) noted that US has been increasingly utilized in procedures involving intra-articular injections. These researchers compared the accuracy of intra-articular injections of the foot and ankle using palpation versus dynamic US in a cadaver model. A total of 14 lightly embalmed cadaver specimens without notable OA were used. A 0.22-G needle was placed by a foot and ankle orthopedic surgeon into the first and second tarsometatarsal (TMT) joints, subtalar joint, and ankle joint. The needle was initially placed using palpation, evaluated with US by an experienced rheumatologist, and re-inserted if necessary. Needle placement was confirmed with injection of an Omnipaque/methylene blue solution and examined under fluoroscopy, followed by dissection. Palpation and US were 100 % accurate in subtalar and ankle joint injections. Using palpation, the needle was correctly placed into the first TMT joint in 3 of 14 cadavers, and in 4 of 14 cadavers for the second TMT joint. Using US, the needle was correctly placed into the first TMT joint in 10 of 14 cadavers, and into the second TMT joint in 8 of 14 cadavers. When grouped, US was significantly more accurate for intra-articular needle placement compared to palpation in the mid-foot (p = 0.003). On 3 specimens, dye extended beyond the second TMT joint. The authors concluded that intra-articular injections of the subtalar and ankle joints could be successfully performed utilizing palpation alone; US guidance significantly increased injection accuracy into the TMT joints compared to palpation alone and therefore US or fluoroscopy was performed when injecting these TMT joints. When using selective diagnostic injections into a TMT joint to assess for the symptomatic joint and potential need for arthrodesis, the injected anesthetic may not remain isolated within that joint. These isolated TMT injections should not be done to answer that question without fluoroscopy confirmation with radiopaque dye demonstrating the injected fluid remained within the one joint of interest.

Superior Cluneal Nerve Injection

Bodner et al (2016) stated that LBP is a disabling and common condition, whose etiology often remains unknown. A suggested, however rarely considered, cause is neuropathy of the medial branch of the superior cluneal nerves (mSCN) – either at the level of the originating roots or at the point where it crosses the iliac crest, where it is ensheathed by an osseo-ligamentous tunnel. Diagnosis and treatment have, to-date, been restricted to clinical assessment and blind infiltration with local anesthetics. In an interventional cadaver study and case-series study, these investigators examined if visualization and assessment of the mSCN with high-resolution US (HRUS) is feasible. Visualization of the mSCN was assessed in 7 anatomic specimens, and findings were confirmed by HRUS-guided ink marking of the nerve and consecutive dissection. In addition, a patient chart and image review was performed of patients assessed at the authors’ department with the diagnosis of mSCN neuropathy. The mSCN could be visualized in 12 of 14 cases in anatomical specimens, as confirmed by dissection; 9 patients were diagnosed with mSCN syndrome of idiopathic or traumatic origin. Diagnosis was confirmed in all of them, with complete resolution of symptoms after HRUS-guided selective nerve block. The authors concluded that it is possible to visualize the mSCN in the majority of anatomical specimens. The patients described may indicate a higher incidence of mSCN syndrome than has been recognized; and mSCN syndrome should be considered in patients with LBP of unknown origin, and HRUS may be able to facilitate nerve detection and US-guided nerve block. Moreover, these researchers stated that these findings were first results that need to be evaluated in a systematic, prospective and controlled manner.

Tarsal Tunnel Injection

Chon et al (2014) stated that tarsal tunnel syndrome (TTS) is a compression neuropathy that results from entrapment of the posterior tibial nerve or its branches. TTS may be treated either by conservative measures, including physical therapy, medications, and steroid injections, or by surgical decompression. Despite a variety of treatments, a few cases of TTS will relapse, and many cases of recurrent TTS will require re-operation. Pulsed radiofrequency (PRF) is known to have a number of advantages for pain management, particularly as this technique does not cause neural compromise such as motor weakness. These investigators reported a new application of US-guided PRF in 2 cases of intractable TTS. Both patients had a long duration of severe foot pain and had been treated with various therapeutic modalities without lasting relief. These researchers applied US-guided PRF to the affected posterior tibial nerve in each patient, and both had significantly reduced pain intensity scores and analgesic requirements without any complications. The authors concluded that US-guided PRF for intractable TTS relieved severe foot pain. It may supersede surgery as a reliable treatment for intractable TTS. This was a small (n = 2) case-series study on the use of US-guided PRF for the treatment of TTS.

Burke and Adler (2017) noted that US-guided tibial nerve block allows for rapid anesthetization of the heel and plantar regions of the foot. These investigators described a variant technique for tibial nerve regional anesthesia utilizing perineural injection of the medial plantar nerve proximal to the sustentaculum tali where the nerve is superficial and readily accessed, with resultant retrograde flow of local anesthetic proximally. Perineural injection of the medial plantar nerve at the infra-malleolar level provides a simple, safe, and effective alternative method to achieve tibial nerve block for regional anesthesia in a variety of procedures.

Yurgil et al (2020) noted that family physicians use anesthesia to provide diagnostic and procedural analgesia for conditions such as neuropathies, fracture reduction, foreign body removals, and complex wound management. Local infiltration of anesthetics is commonly used in this setting because of the ease of use, safety, and effectiveness of the procedure. Nerve blocks are a specific regional anesthesia technique that blocks nerve function distal to the injection site. An understanding of the sensory distribution of the peripheral nervous system is essential in determining the safest and most effective nerve block for the procedure. There are various nerve block techniques, including landmark-guided and US-guided. Ultrasound guidance increases the effectiveness of the nerve block while decreasing complications when compared with other techniques. Depending on the required area of anesthesia for the procedure, various points throughout the lower extremity can be used to block the lateral femoral cutaneous, common peroneal, saphenous, tibial, deep peroneal, superficial peroneal, and sural nerves.

Tendon Injection

Juel et al (2013) established a method for injecting corticosteroid into the rotator interval under US guidance and measured the effect on function, pain and ROM after 4 and 12 weeks. This study involved a multi-center cohort trial and was carried out at out-patient clinics of the physical medicine and rehabilitation departments in Norway. A total of 39 patients with adhesive capsulitis lasting between 3 and 12 months were included in this trial; US-guided corticosteroid and lidocaine injection into the rotator interval medial to the biceps tendon using 20-mg triamcinolone hexacetat and 3-ml 20 mg/ml xylocaine. Change in the shoulder pain and disability index score (SPADI) after 12 weeks was recorded. The change in SPADI was 42 points (95 % CI: 33 to 51). Changes in the secondary outcomes showed highly statistically significant increase in active and passive ROM. One US-guided corticosteroid injection into the rotator interval appeared to give significant improvement in SPADI and active ROM after 12 weeks. The authors concluded that this study was regarded as regular clinical procedure as injections with triamcinolone already is standard treatment. This was a small study (n = 39) with short-term follow-up (12 weeks).

Wheeler et al (2016) compared outcomes after 2 different high-volume image-guided injection (HVIGI) procedures performed under direct US guidance in patients with chronic non-insertional Achilles tendinopathy. In group A, HVIGI involved high-volume (10-ml of 1 % lidocaine combined with 40-ml of saline) and no dry needling. In group B, HVIGI involved a smaller volume (10-ml of 1 % lidocaine combined with 20-ml of saline) and dry needling of the Achilles tendon. A total of 34 patients were identified from the clinical records, with mean age of 50.6 (range of 26 to 83) years and mean follow-up duration of 277 (range of 49 to 596) days. The change between the pre-injection and post-injection Victorian Institute of Sports Assessment-Achilles scores of 33.4 ± 22.5 points in group A and 6.94 ± 22.2 points in group B, was statistically significant (p = 0.002). In group A, 3 patients (16.7 %) required surgical treatment compared with 6 patients (37.5 %) in group B requiring surgical treatment (p = 0.180). The authors concluded the findings of this study indicated that a higher volume without dry needling compared with a lower volume with dry needling resulted in greater improvement in non-insertional Achilles tendinopathy. However, confounding factors meant it was not possible to state that this difference was solely due to different injection techniques. This was a small study (n = 34); its findings need to be validated by well-designed studies.

Mardani-Kivi et al (2018) compared clinical results of US-guided corticosteroid injection, intra-sheath versus extra-sheath of the finger flexor tendon. A total of 166 patients with trigger finger were evaluated in a triple-blind, randomized clinical trial study. All the patients were injected with 1-ml of 40 mg/ml methyl prednisolone acetate, under US-guidance; 50 % the patients were injected extra-sheath, while the other 50 % were injected intra-sheath at the level of first annular pulley. The 2 groups were comparable in baseline characteristics (age, gender, dominant hand, involved hand and finger, and the symptoms duration). No significant difference was observed in the 2 groups with regards to Quinnell grading. In the final visit, 94 % of patients from each group were symptom-free. The authors concluded that results of corticosteroid injection intra-sheath or extra-sheath of the finger flexor tendon under US guidance in patients with trigger finger were comparably alike; extra-sheath injection at the level of A1 pulley was as effective as an intra-sheath administration. The main drawback of this trial was the lack of a non-US guidance comparison group.

Laurell et al (2011) noted that the ankle region is frequently involved in juvenile idiopathic arthritis (JIA) but difficult to examine clinically due to its anatomical complexity. These investigators examined the role of US of the ankle and mid-foot (ankle region) in JIA. Doppler-US detected synovial hypertrophy, effusion and hyperemia and US was used for guidance of steroid injection and assessment of treatment efficacy. A total of 40 swollen ankles regions were studied in 30 patients (median age of 6.5 years, range of 1 to 16) with JIA. All patients were assessed clinically, by US (synovial hypertrophy, effusion) and by color Doppler (synovial hyperemia) before and 4 weeks after US-guided steroid injection. US detected 121 compartments with active disease (joints, tendon sheaths and 1 ganglion cyst). Multiple compartments were involved in 80 % of the ankle regions. The talo-crural joint, posterior subtalar joint, mid-foot joints and tendon sheaths were affected in 78 %, 65 %, 30 % and 55 %, respectively; 50 active tendon sheaths were detected, and multiple tendons were involved in 12 of the ankles. US guidance allowed accurate placement of the corticosteroid in all 85 injected compartments, with a low rate of subcutaneous atrophy (4.7 %). Normalization or regression of synovial hypertrophy was obtained in 89 %, and normalization of synovial hyperemia in 89 %. Clinical resolution of active arthritis was noted in 72 % of the ankles. The authors concluded that US enabled exact guidance of steroid injections with a low rate of subcutaneous atrophy, and was well-suited for follow-up examinations. Normalization or regression of synovial hypertrophy and hyperemia was achieved in most cases, suggesting that US assessment prior to steroid injection, and US guidance of injections in this region would potentially improve treatment efficacy.

Young et al (2015) stated that the subtalar joint is commonly affected in children with JIA and is challenging to treat percutaneously. These researchers described the technique for treating the subtalar joint with US-guided corticosteroid injections in children and young adults with JIA and evaluated the safety of the treatment. They retrospectively analyzed 122 patients (aged 15 months to 29 years) with JIA who were referred by a pediatric rheumatologist for corticosteroid injection therapy for symptoms related to the hind-foot or ankle. In these patients the diseased subtalar joint was targeted for therapy, often in conjunction with adjacent affected joints or tendon sheaths of the ankle. They used a protocol based on age, weight and joint for triamcinolone hexacetonide or triamcinolone acetonide dose prescription. A total of 241 subtalar joint corticosteroid injections were performed under US guidance, including 68 repeat injections for recurrent symptoms in 26 of the 122 children and young adults. The average time interval between repeat injections was 24.8 months (range of 2.2 to 130.7, median of 14.2). Subcutaneous tissue atrophy and skin hypo-pigmentation were the primary complications, which occurred in 3.9 % of the injections. The authors concluded that with appropriate training and practice, the subtalar joint could be reliably and safely targeted with US-guided corticosteroid injection to treat symptoms related to JIA.

Tenotomy for the Treatment of Lateral Epicondylitis

Shergill and Choudur (2019) stated that lateral epicondylitis is a painful condition related to the myotendinous origin of the extensor muscles at the lateral epicondyle of the humerus. Primary treatment typically involves the use of rest, non-steroidal anti-inflammatory drugs (NSAIDs), and physiotherapy. However, in refractory cases where conventional therapy is ineffective, ultrasound (US)-guided injection therapies have become a growing form of treatment. These include needle tenotomy, autologous whole blood injection (AWB), platelet-rich plasma (PRP) injection and steroid injection. The consensus regarding the efficacy of individual approaches of US-guided treatment is unclear in the literature; and was explored further in this review. When evaluating these injection therapies individually, there are multiple case series describing the efficacy of each intervention in refractory lateral epicondylitis. A systematic review of needle tenotomy demonstrated an improvement in pain symptoms for patients with this condition, but all studies were poorly designed with no placebo or control group. For PRP therapy, a systematic review performed in 2013 demonstrated a statistically significant improvement in pain and functionality for refractory lateral epicondylitis; however, these studies were similarly associated with a high risk of bias. Autologous whole blood injection has been examined via well-designed studies to show statistically significant reductions in pain with this intervention. But very few studies in total have been completed using AWB for lateral epicondylitis; thus, no clear conclusions could be drawn at this time. Finally, corticosteroid use overall is unsupported in the evidence both in the short- and long-term, especially given that this condition is not an inflammatory pathology.

Furthermore, an UpToDate review on “Elbow tendinopathy (tennis and golf elbow)” (Jayanthi, 2021) lists “ultrasound-guided percutaneous needle tenotomy” as an investigational treatment of possible benefit.

Tibiofibular Joint Injection

In a cadaveric study, Smith et al (2010) described a technique for sonographically-guided proximal tibiofibular joint (PTFJ) injections and compared its accuracy with that of palpation-guided injections. A single experienced operator completed 12 sonographically-guided and 12 palpation-guided PTFJ injections in un-embalmed cadavers. The injection order was randomized, and all injections were completed with diluted colored latex. Co-investigators blinded to the injection technique dissected each specimen and graded the colored latex location as accurate (in the PTFJ), accurate with overflow (within the PTFJ but also in other regions), or inaccurate (no latex in the joint). For statistical analysis, all injections placing latex within the PTFJ were considered "accurate”, whereas "inaccurate" injections resulted in no PTFJ latex. All 12 sonographically-guided PTFJ injections accurately placed latex into the PTFJ (100 % accuracy), whereas only 7 of 12 palpation-guided injections (58 %) placed latex within the PTFJ (p = 0.01). All 5 inaccurate palpation-guided injections were superficial and inferior to the PTFJ; 4 of 12 accurate sonographically-guided PTFJ injections (33 %) showed some overflow into the adjacent anterior musculature, whereas 5 of the accurate palpation-guided injections (42 %) resulted in overflow into the anterior musculature (n = 1), knee joint (n = 2), or both (n = 2). The authors concluded that the findings of this cadaveric study suggested that sonographic guidance can be used to inject the PTFJ with a high degree of accuracy and should be considered superior to palpation guidance. Clinicians should consider using US guidance to inject the PTFJ for diagnostic or therapeutic purposes when clinically indicated. This was a cadaveric study.

Daniels et al (2018) noted that office-based US has become increasingly available in many settings, and its use to guide joint and soft tissue injections has increased. Many studies have been carried out to examine the use of US-guided injections over traditional landmark-guided injections, with a rapid growth in the literature over the past few years. These researchers performed a comprehensive review of the literature to demonstrate increased accuracy of US-guided injections regardless of anatomic location. In the upper extremity, US-guided injections have been shown to provide superior benefit to landmark-guided injections at the glenohumeral joint, the subacromial space, the biceps tendon sheath, and the joints of the hand and wrist; US-guided injections of the acromioclavicular and the elbow joints have not been shown to be more effective. In the lower extremity, US-guided injections at the knee, ankle, and foot have superior efficacy to landmark-guided injections. Conclusive evidence is not available regarding improved efficacy of US-guided injections of the hip, although landmark-guided injection was performed less commonly at the hip joint. Ultrasound-guided injections are overall more accurate than landmark-guided injections. The authors concluded that while current studies indicated that US guidance improved efficacy and cost-effectiveness of many injections, these studies were limited; and more research is needed. This review did not specifically address US-guided injections into the tibiofibular joint, but the study by Smith et al (2010) was cited in the “References”.

Trigger Finger Injection

Callegari et al (2011) noted that stenosing tenosynovitis (trigger finger) is one of the most common causes of pain and disability in the hand, which may often require treatment with anti-inflammatory drugs, corticosteroid injection, or open surgery. However, there is still room for improvement in the treatment of this condition by corticosteroid injection. The mechanical, viscoelastic, and anti-nociceptive properties of hyaluronic acid (HA) may potentially support the use of this molecule in association with corticosteroids for the treatment of trigger finger. In a single-center, open-label, randomized study, these researchers examined the feasibility and safety of ultrasound (US)-guided injection of a corticosteroid and HA compared, for the first time, with open surgery for the treatment of trigger finger. Consecutive patients aged between 35 and 70 years with US-confirmed diagnosis of trigger finger were included. Patients were randomly assigned to either US-guided injection of methylprednisolone acetate 40 mg/ml with 0.8 ml lidocaine into the flexor sheath plus injection of 1 ml HA 0.8 % 10 days later (n = 15; group A), or to open surgical release of the first annular pulley (n = 15; group B). Clinical assessment of the digital articular chain was conducted prior to treatment and after 6 weeks, and 3, 6, and 12 months. The duration of abstention from work and/or sports activity, and any treatment complications or additional treatment requirements (e.g., physiotherapy, compression, medication) were also recorded. A total of 14 patients (93.3 %) in group A had complete symptom resolution at 6 months, which persisted for 12 months in 11 patients (73.3% ), while 3 patients experienced recurrences and 1 experienced no symptom improvements. No patients in group A reported major or minor complications during or after corticosteroid injection, or required a compression bandage. All 15 patients in group B achieved complete resolution of articular impairment by 3 weeks after surgery, but 10 patients were assigned to physiotherapy and local and/or oral analgesics for complete resolution of symptoms, which was approximately 30 to 40 days post-surgery. The mean duration of abstention from work and/or sport was 2 to 3 days in group A and 26 days in group B. The authors concluded that although the limited sample size did not allow any statistical comparison between treatment groups, and therefore all the findings should be regarded as preliminary, the results of this explorative study suggested that US-guided injection of a corticosteroid and HA could be a safe and feasible approach for the treatment of trigger finger. It was also associated with a shorter recovery time than open surgery, which led to a reduced abstention from sports and, in particular, work activities, and thus may have some pharmaco-economic implications, which may be further examined. In light of the promising findings obtained in this investigation, further studies comparing US-guided injection of corticosteroid plus HA with corticosteroid alone are recommended in order to clarify the actual benefits attributable to HA.

The authors stated that this study had several drawbacks. A lack of a corticosteroid-only treatment arm meant that any benefits of adding HA to the regimen of injection compared with corticosteroid alone cannot be shown. In light of the promising results obtained in this investigation, further study comparing ultrasound-guided injection of corticosteroid plus HA with corticosteroid alone, or exploring other treatment strategies (e.g., no US-guided injection, corticosteroid only versus surgery) is recommended. Furthermore, due to small patient numbers in this study (a total of 30 subjects) , it was not possible to analyze for any trends in the duration of symptoms or number of injections and success rates. These researchers stated that further studies with a larger sample size are needed to provide new insights on the safety and effectiveness of US-guided injection of corticosteroid plus HA. It also must be acknowledged that, due to the explorative nature of this study and the low number of patients enrolled, neither a calculation of power nor a statistical comparison between groups were performed.

In a prospective, double-blinded, randomized controlled trial (RCT), Liu et al (2015) examined the effects of US-guided injections of HA versus steroid for trigger fingers in adults. Subjects with a diagnosis of trigger finger (n = 36; 39 affected digits) received treatment and were evaluated. Subjects were randomly assigned to HA and steroid injection groups. Both study medications were injected separately via US guidance with 1 injection. The classification of trigger grading, pain, functional disability, and patient satisfaction were evaluated before the injection and 3 weeks and 3 months after the injection. At 3 months, 12 patients (66.7 %) in the HA group and 17 patients (89.5 %) in the steroid group exhibited no triggering of the affected fingers (p = 0.124). The treatment results at 3 weeks and 3 months showed similar changes in the Quinnell scale (p = 0.057 and 0.931, respectively). A statistically significant interaction effect between group and time was found for visual analog scale (VAS) and Michigan Hand Outcome Questionnaire (MHQ) evaluation (p < 0.05). The steroid group had a lower VAS at 3 months after injection (steroid 0.5 ± 1.1 versus HA 2.7 ± 2.4; p < 0.001). The HA group demonstrated continuing significant improvement in MHQ at 3 months (change from 3 week: steroid -2.6 ± 14.1 versus HA 19.1 ± 37.0; p = 0.023; d = 0.78). The authors concluded that US-guided injection of HA demonstrated promising results for the treatment of trigger fingers. These researchers stated that the optimal frequency, dosage, and molecular weight of HA injections for trigger fingers deserve further investigation for future clinical applications.

Cecen et al (2015) noted that trigger digit is one of the most common causes of pain and disability in the hand. The mainstay of conservative treatment of this disease has been local steroid injection into the tendon sheath. In a prospective, randomized, case-control study, these investigators examined the clinical benefit of an US-guided corticosteroid injection compared to a blinded application. A total of 74 patients, who suffered from persistent or increasing symptoms of a single trigger digit, were enrolled in this trial. All patients were treated with an injection of 40 mg/1 ml methylprednisolone acetate into the flexor tendon sheath at the level of the A1 pulley; 50 % of the patients had their injections under US control (USG) and 50 % without (blinded injection group, BIG). Associated metabolic diseases were recorded. At the 6-week and 6-month follow-up examinations, the complication rate and the need for a second injection were assessed. The outcome was rated using the Quinnell grading. The pain level was assessed using the VAS. A total of 4 patients were excluded due to lack of follow-up. Both study groups were comparable in respect of age, hand dominance and associated diseases. There were significantly more female patients in the USG group (32 versus 23 %). After the corticosteroid injections, all patients improved significantly in terms of pain level and the Quinnell grading at 6 weeks and 6 months after the intervention in comparison to the pre-injection status. There were no significant differences between the groups; 9 patients (13 %) needed a second injection (6 of BIG, 3 of USG), all of whom had diabetes mellitus. No local complications were observed following the injections. The authors concluded that the use of US-guided injection of corticosteroid may be associated with extra time and effort, with no superior clinical benefits compared to the blinded technique. Level of Evidence = 1 (prospective randomized study).

Wang et al (2017) stated that US is a versatile imaging modality that can be used by upper extremity (UE) surgeons for diagnostic purposes and guided injections. The perceptions of US for diagnosis and treatment among UE surgeons and its barriers for adoption have not been formally surveyed. These researchers determined the current usage of musculoskeletal US for diagnostic purposes and guided injections by UE surgeons and their reasons for using it or not using it in practice. A 22-question survey was distributed to the American Society for Surgery of the Hand (ASSH). The survey questions consisted of respondent characteristic questions and questions pertaining to the use of US. Chi-square analysis was performed to assess for a difference in US usage across respondent characteristics. A total of 304 (43 %) answered that they have an US machine in their office; 51 % (362) of the respondents used US for diagnostic purposes; 55 (8 %) of the survey respondents used US to diagnose carpal tunnel syndrome; 168 (23.5 %) respondents reported that they used US for guided injections. There was a statistically significant difference between access to an US machine in the office by practice setting and use of US for diagnostic purposes by practice setting. The authors concluded that the use of US by UE surgeons is split for diagnostic purposes, with fewer surgeons using US to diagnose carpal tunnel syndrome and guided injections. These investigators stated that US machine availability and the use of US for diagnosis appear to be influenced by practice setting.

Hansen et al (2017) noted that trigger finger is a common condition with a lifetime prevalence of 2 %. Corticosteroid injection is often considered as a first-line intervention with reported cure rates between 60 % and 90 % in observational cohorts. However, open surgery remains the most effective treatment with reported cure rates near 100 %. Head-to-head trials on these treatments are limited. In a single-center RCT, these investigators examined the efficacy of open surgery compared with US-guided corticosteroid injections with a 1-year follow-up. A total of 165 patients received either open surgery (n = 81) or US-guided corticosteroid injection (n = 84). Follow-up was conducted at 3 and 12 months. If the finger had normal movement or normal movement with discomfort at latest follow-up, the outcome was considered a success. Secondary outcomes were post-procedural pain and complications. The groups were similar at baseline except for lower alcohol consumption in the open surgery group. At 3 months, 86 % and 99 % were successfully treated after corticosteroid injection and open surgery, respectively. At 12 months, 49 % and 99 % were considered successfully treated after corticosteroid injection and open surgery, respectively. The pain score at latest follow-up was significantly higher in the corticosteroid injection group. Complications after open surgery were more severe and included 3 superficial infections and 1 iatrogenic nerve lesion. After corticosteroid injection 11 patients experienced a steroid flare and 2 had fat necrosis at the site of injection. The authors concluded that open surgery was superior to US-guided corticosteroid injections; however, complications following open surgery were more severe.

Thread Trigger Finger Release With or Without Hydrodissection

Guo et al (2018) noted that after the thread transecting technique was successfully applied for the thread carpal tunnel release, these investigators researched using the same technique in the thread trigger finger release (TTFR). This study was designed to test the operational feasibility of the TTFR on cadavers and verify the limits of division on the first annular (A1) pulley to ensure a complete trigger finger release with minimal iatrogenic injuries. The procedure of TTFR was performed on 14 fingers and 4 thumbs of 4 un-embalmed cadaveric hands. After the procedures, all fingers and thumbs were dissected and visually assessed. All of the digits and thumbs demonstrated a complete A1 pulley release. There was no injury to the neurovascular bundle (radial digital nerve in case of thumb), flexor tendon, or A2 pulley for each case. The authors concluded that this cadaveric study showed that the technique of TTFR was safe and effective, and future clinical study is needed to verify the findings of this study.

Furthermore, an UpToDate review on "Trigger finger (stenosing flexor tenosynovitis)" (Blazar and Aggarwal, 2019) does not mention thread trigger finger release as a therapeutic option.

Paulius and Maguina (2009) stated that trigger fingers can be treated by open or percutaneous division of the A1 pulley. The open approach allows for visualization of the pulley, the tendon, and the adjacent neurovascular bundles. The percutaneous trigger finger release (PTFR) lacks an incision and is thought to lead to a quicker recovery, but the safety and efficacy of this blind procedure are often questioned. Ultrasound (US) imaging has recently been introduced as an adjunct for guiding the needle during PTFR. This study was designed to examine the safety and efficacy of needle trigger finger release with added US imaging. A total of 18 fresh cadaver A1 pulleys were divided percutaneously and then evaluated by converting to an open technique and examining the pulleys, the tendons, and the neurovascular bundles. This study's US images demonstrated repeated puncture of the tendon sheath and of the neurovascular bundle during PTFR. The subsequent dissection revealed 3 out of 18 tendons with visible lacerations and 15 out of 18 A1 pulleys with incomplete division. The authors concluded that US-guided PTFR can be complicated by flexor tendon lacerations, potential injury to neurovascular bundles, and incomplete division of the A1 pulleys. These researchers stated that while the clinical significance of these findings was unclear, it raised questions regarding the safety and efficacy of PTFR, even when adding US guidance.

Rajeswaran et al (2009) evaluated a new technique for US-guided percutaneous release of the annular pulley in trigger digit using a modified hypodermic needle. A total of 35 US-guided percutaneous releases were performed on 25 patients diagnosed and referred by hand surgeons in the authors’ institution over 16 months from October 2006. Inclusion criteria were as follows: adulthood, triggering present for at least 4 months, failure to respond to conservative management or steroid injections, no previous history of pulley release in the affected digit. Under US guidance, the affected pulley was released using a standard 19-G hypodermic needle bent at 2 points as the cutting device. Follow-up took place at 12 weeks and 6 months with improvement in triggering and clinically graded pain. At follow-up, no complications had occurred and all patients demonstrated improvement in their triggering, with complete resolution in 32 digits (91 %), good improvement in 2 digits (6 %) and some improvement in 1 digit (3 %). The authors concluded that this new technique used a widely available and safe cutting device and was safe and could be used to provide definitive management for trigger finger, allowing the procedure to be performed in a variety of clinical settings.

Rojo-Manaute et al (2010) defined in volunteers a safe area for performing a percutaneous intra-sheath first annular (A1) pulley release under US guidance in cadavers for the treatment of trigger fingers. First, in 100 fingers of 10 volunteers, these researchers used Doppler US to determine the limits of the sectors enclosing structures at risk (arteries and tendons). From the synovial sheath's most volar point, these investigators determined the relative position of the arterial walls and the distance to the flexor tendons. A scatter-plot overlay of the arterial positions was digitally analyzed for determining the limits of the safe area. Second, these researchers released the A1 pulley in 46 fingers from 5 cadavers, directing the edge of the cutting device toward the safe area from an intra-sheath instrument position. The precision, safety, and efficacy of the release were evaluated by surgical exposure of the A1 and A2 pulleys and the neurovascular bundles. In the volunteers, these investigators observed a volar safe area from +6.1° to +180°. Surgical precision was good in the cadavers, with no injuries to adjacent structures, a complete release in 44 fingers (95.7 %), and an incomplete release of less than 1.6 mm in 2 fingers. The authors concluded that the findings of this study determined a safe volar area for aiming surgical instruments from an intra-sheath position for percutaneous US-guided A1 pulley release. The technique can be performed safely in all fingers, but these researchers suggested being cautious in the thumb and converting the surgery to an open procedure if US visualization is not optimal.

Hoang et al (2016) noted that trigger finger is the most common entrapment tendinopathy, with a lifetime risk of 2 % to 3 %. Open surgical release of the flexor tendon sheath is a commonly performed procedure associated with a high rate of success. Despite reported success rates of over 94 %, PFTR remains a controversial procedure because of the risk of iatrogenic digital neurovascular injury. These researchers examined the safety and efficacy of traditional percutaneous and US-guided A1 pulley releases performed on a perfused cadaveric model. First annular pulley releases were performed percutaneously using an 18-G needle in 155 digits (124 fingers and 31 thumbs) of un-embalmed cadavers with restored perfusion. A total of 45 digits were completed with US guidance and 110 digits were completed without it. Each digit was dissected and assessed regarding the amount of release as well as neurovascular, flexor tendon, and A2 pulley injury. Overall, 114 A1 pulleys were completely released (74 %). There were 38 partial releases (24 %) and 3 complete misses (2 %). No significant flexor tendon injury was observed. Longitudinal scoring of the flexor tendon was found in 35 fingers (23 %). There were no lacerations to digital nerves and 1 ulnar digital artery was partially lacerated (1 %) in a middle finger with a partial flexion contracture that prevented appropriate hyper-extension. The US-assisted and blind PTFR techniques had similar complete pulley release and injury rates. The authors concluded that both traditional and US-assisted percutaneous release of the A1 pulley can be performed for all fingers. Perfusion of cadaver digits enhanced surgical simulation and evaluation of PTFR beyond those of previous cadaveric studies. The addition of vascular flow to the digits during percutaneous release allowed for Doppler flow assessment of the neurovascular bundle and evaluation of vascular injury.

Appendix

Note on Documentation Requirements: CPT guidelines state that "Ultrasound guidance procedures also require permanently recorded images of the site to be localized, as well as a documented description of the localization process, either separately or within the report of the procedure for which the guidance is utilized. Use of ultrasound, without thorough evaluation of organ(s), or anatomic region, image documentation, and final, written report, is not separately reportable".

Table: CPT Codes / HCPCS Codes / ICD-10 Codes
Code	Code Description
*Information in the [brackets] below has been added for clarification purposes. Codes requiring a 7th character are represented by "+"* :
*Ultrasonic guidance for needle placement*:
CPT codes covered if selection criteria are met:
76942	Ultrasonic guidance for needle placement (eg, biopsy, aspiration, injection, localization device), imaging supervision and interpretation
76998	Ultrasonic guidance, intraoperative
CPT codes for procedures where 76942 and 76998 are covered if selection criteria are met: (not all inclusive):
Piriformis muscle injection, Popliteal nerve block, Serratus plane block, Infraclavicular nerve block, IPACK nerve block, needle placement, lavage, and debridement of calcific tendinosis of the shoulder, Pectoral nerve block (PECS 1 and PECS 2) – no specific code
20526	Injection, therapeutic (eg, local anesthetic, corticosteroid), carpal tunnel
20606	Arthrocentesis, aspiration and/or injection, intermediate joint or bursa (eg, temporomandibular, acromioclavicular, wrist, elbow or ankle, olecranon bursa); with ultrasound guidance, with permanent recording and reporting [scapular thoracic bursitis injection] [not covered for Iliopsoas bursa injection] [Not covered for ankle bursa injection] [Not covered for calcaneal/retrocalcaneal bursa injection] [Not covered for foot/heel injection for adventitious bursitis/capsulitis] [Not covered for tibiofibular joint injection]
20611	Arthrocentesis, aspiration and/or injection, major joint or bursa (eg, shoulder, hip, knee, subacromial bursa); with ultrasound guidance, with permanent recording and reporting [scapular thoracic bursitis injection] [not covered for Iliopsoas bursa injection] [not covered for trochanteric bursa injection] [Not covered for intraarticular injection for the management of shoulder impingement/pain] [Not covered for subacromial bursitis injection] [long head of the biceps injection] [ischial bursa and gluteus medius injection]
25000	Incision, extensor tendon sheath, wrist (eg, deQuervains disease)
27345	Excision of synovial cyst of popliteal space (eg, Baker's cyst)
31717	Catheterization with bronchial brush biopsy
32096	Thoracotomy, with diagnostic biopsy(ies) of lung infiltrate(s) (eg, wedge, incisional), unilateral
32097	Thoracotomy, with diagnostic biopsy(ies) of lung nodule(s) or mass(es) (eg, wedge, incisional), unilateral
32098	Thoracotomy, with biopsy(ies) of pleura
32400	Biopsy, pleura, percutaneous needle
32408	Core needle biopsy, lung or mediastinum, percutaneous, including imaging guidance, when performed
32607	Thoracoscopy; with diagnostic biopsy(ies) of lung infiltrate(s) (eg, wedge, incisional), unilateral
32608	with diagnostic biopsy(ies) of lung nodule(s) or mass(es) (eg, wedge, incisional), unilateral
32609	with biopsy(ies) of pleura
47000	Biopsy of liver, needle; percutaneous
+47001	when done for indicated purpose at time of other major procedure (List separately in addition to code for primary procedure)
47100	Biopsy of liver, wedge
48100	Biopsy of pancreas, open (eg, fine needle aspiration, needle core biopsy, wedge biopsy)
48102	Biopsy of pancreas, percutaneous needle
49180	Biopsy, abdominal or retroperitoneal mass, percutaneous needle
49321	Laparoscopy, surgical; with biopsy (single or multiple)
50040 - 50081	Incision, renal
50220 - 50240	Excision, renal
50384 - 50386	Introduction, renal
50390 - 50431, 50433, 50435	Other Introduction, renal
50541, 50543 - 50549	Laparoscopy, renal
50590 - 50593	Lithotripsy
55700	Biopsy, prostate; needle or punch, single or multiple, any approach
55705	incisional, any approach
58974	Embryo transfer, intrauterine
58976	Gamete, zygote, or embryo intrafallopian transfer, any method
60100	Biopsy thyroid, percutaneous core needle
62270	Spinal puncture, lumbar, diagnostic
62272	Spinal puncture, therapeutic, for drainage of cerebrospinal fluid (by needle or catheter)
62329	Spinal puncture, therapeutic, for drainage of cerebrospinal fluid (by needle or catheter); with fluoroscopic or CT guidance
62350	Implantation, revision or repositioning of tunneled intrathecal or epidural catheter, for long-term medication administration via an external pump or implantable reservoir/infusion pump; without laminectomy
62351	with laminectomy
62360	Implantation or replacement of device for intrathecal or epidural drug infusion; subcutaneous reservoir
62361	nonprogrammable pump
62362	programmable pump, including preparation of pump, with or without programming
64413	Injection, anesthetic agent; cervical plexus [Interscalene nerve block] and [Supraclavicular nerve block for post-operative pain control]
64415	brachial plexus, single [Interscalene nerve block] and [Supraclavicular nerve block for post-operative pain control]
64416	brachial plexus, continuous infusion by catheter (including catheter placement [Interscalene nerve block] and [Supraclavicular nerve block for post-operative pain control]
64417	Injection(s), anesthetic agent(s) and/or steroid; axillary nerve [Axillary brachial plexus nerve block]
64420	Injection, anesthetic agent; intercostal nerve, single [subpectoral nerve block (parasternal T2 to T6 intercostal block)]
64421	intercostal nerves, multiple, regional block [subpectoral nerve block (parasternal T2 to T6 intercostal block)]
64425	Injection(s), anesthetic agent(s) and/or steroid; ilioinguinal, iliohypogastric nerves
64445	sciatic nerve, single
64446	sciatic nerve, continuous infusion by catheter (including catheter placement) [not covered for gluteal nerve injection]
64447	femoral nerve, single arterial line placement [Fascia iliaca block for post-operative pain following hip and knee surgeries] [Not covered for lateral pericapsular nerve group (PENG) nerve block during total hip arthroplasty]
64448	femoral nerve, continuous infusion by catheter (including catheter placement) [Fascia iliaca block for post-operative pain following hip and knee surgeries] [Not covered for lateral pericapsular nerve group (PENG) nerve block during total hip arthroplasty]
64450	other peripheral nerve or branch [femoral nerve block for post-operative knee pain] and [quadratus lumborum nerve block for post-operative pain control after abdominal surgery] [lateral femoral cutaneous nerve block for meralgia paresthetica] [Pectoralis nerve block for the management of post-operative pain following mastectomy]
64486	Transversus abdominis plane (TAP) block (abdominal plane block, rectus sheath block) unilateral; by injection(s) (includes imaging guidance, when performed) [post-operative pain following abdominal surgery]
64487	by continuous infusion(s) (includes imaging guidance, when performed) [post-operative pain following abdominal surgery]
64488	Transversus abdominis plane (TAP) block (abdominal plane block, rectus sheath block) bilateral; by injections (includes imaging guidance, when performed) [post-operative pain following abdominal surgery]
64489	by continuous infusions (includes imaging guidance, when performed) [post-operative pain following abdominal surgery]
92928	Percutaneous transcatheter placement of intracoronary stent(s), with coronary angioplasty when performed; single major coronary artery or branch
+92929	each additional branch of a major coronary artery (List separately in addition to code for primary procedure)
92933	Percutaneous transluminal coronary atherectomy, with intracoronary stent, with coronary angioplasty when performed; single major coronary artery or branch
+92934	each additional branch of a major coronary artery (List separately in addition to code for primary procedure)
92937	Percutaneous transluminal revascularization of or through coronary artery bypass graft (internal mammary, free arterial, venous), any combination of intracoronary stent, atherectomy and angioplasty, including distal protection when performed; single vessel
+92938	each additional branch subtended by the bypass graft (List separately in addition to code for primary procedure)
92941	Percutaneous transluminal revascularization of acute total/subtotal occlusion during acute myocardial infarction, coronary artery or coronary artery bypass graft, any combination of intracoronary stent, atherectomy and angioplasty, including aspiration thrombectomy when performed, single vessel
92943	Percutaneous transluminal revascularization of chronic total occlusion, coronary artery, coronary artery branch, or coronary artery bypass graft, any combination of intracoronary stent, atherectomy and angioplasty; single vessel
+92944	each additional coronary artery, coronary artery branch, or bypass graft (List separately in addition to code for primary procedure)
92974	Transcatheter placement of radiation delivery device for subsequent coronary intravascular brachytherapy (List separately in addition to code for primary procedure)
CPT codes for procedures where 76942 and 76998 are not covered for indications listed in the CPB:
Erector spinae plane (ESP) block, Gluteal nerve injection, Hydro dissection of infrapatellar saphenous nerve, Iliotibial band hydro dissection, Lavage of the shoulder joint, Median nerve block, Trigger finger injection/trigger finger release without hydro dissection, clavi-pectoral fascial plane block, iliotibial (IT) band injection, percutaneous bursectomy of the pretibial tubercle bursa, scar tissue injection – no specific code
0394T	High dose rate electronic brachytherapy, skin surface application, per fraction, includes basic dosimetry, when performed [superficial radiation treatment of skin cancer]
20550	Injection(s); single tendon sheath, or ligament, aponeurosis (eg, plantar "fascia") [iliopsoas tendon sheath] [medial calcaneal nerve sheath injection] [Adductor longus tendon injection] [Dorsal compartments of the wrist injection] [gluteal tendon sheath injections for hip and/or low back pain] [iliopsoas tendon injection] [nuchal ligament and supraspinous ligament injection] [peritendon injection for the treatment of Achilles tendinopathy] [peroneal tendon sheath injection]
20551	Injection(s); single tendon origin/insertion [psoas tendon injection] [Adductor longus tendon injection] [Dorsal compartments of the wrist injection] gluteal tendon sheath injections for hip and/or low back pain] [iliopsoas tendon injection] [nuchal ligament and supraspinous ligament injection] [peritendon injection for the treatment of Achilles tendinopathy] [peroneal tendon sheath injection]
20552	single or multiple trigger point(s), 1 or 2 muscle(s)
20553	single or multiple trigger point(s), 3 or more muscles
20604	Arthrocentesis, aspiration and/or injection, small joint or bursa (eg, fingers, toes); with ultrasound guidance, with permanent recording and reporting [metatarsophalangeal and/or metatarsal cuneiform joint injection]
20612	Aspiration and/or injection of ganglion cyst(s) any location
26055	Tendon sheath incision (eg, for trigger finger) [Trigger finger injection/trigger finger release without hydro dissection]
24357 – 24359	Tenotomy, elbow, lateral or medial
27000	Tenotomy, adductor of hip, percutaneous
36465	Injection of non-compounded foam sclerosant with ultrasound compression maneuvers to guide dispersion of the injectate, inclusive of all imaging guidance and monitoring; single incompetent extremity truncal vein (eg, great saphenous vein, accessory saphenous vein)
36466	multiple incompetent truncal veins (eg, great saphenous vein, accessory saphenous vein), same leg
36470	Injection of sclerosant; single incompetent vein (other than telangiectasia)
36471	multiple incompetent veins (other than telangiectasia), same leg
64405	Injection(s), anesthetic agent(s) and/or steroid; greater occipital nerve
64418	Injection(s), anesthetic agent(s) and/or steroid; suprascapular nerve [dorsal scapular nerve block]
64449	lumbar plexus, posterior approach, continuous infusion by catheter (including catheter placement)
64479	Injection(s), anesthetic agent and/or steroid, transforaminal epidural, with imaging guidance (fluoroscopy or CT); cervical or thoracic, single level
+64480	cervical or thoracic, each additional level (List separately in addition to code for primary procedure)
64483	lumbar or sacral, single level
+64484	lumbar or sacral, each additional level (List separately in addition to code for primary procedure)
64615	Chemodenervation of muscle(s); muscle(s) innervated by facial, trigeminal, cervical spinal and accessory nerves, bilateral (eg, for chronic migraine)
64616	Chemodenervation of muscle(s); neck muscle(s), excluding muscles of the larynx, unilateral (eg, for cervical dystonia, spasmodic torticollis)
77767	Remote afterloading high dose rate radionuclide skin surface brachytherapy, includes basic dosimetry, when performed; lesion diameter up to 2.0 cm or 1 channel [superficial radiation treatment of skin cancer]
77768	Remote afterloading high dose rate radionuclide skin surface brachytherapy, includes basic dosimetry, when performed; lesion diameter over 2.0 cm and 2 or more channels, or multiple lesions [superficial radiation treatment of skin cancer]
HCPCS codes for procedures where 76942 and 76998 are not covered for indications listed in the CPB:
J7318	Hyaluronan or derivative, durolane, for intra-articular injection, 1 mg
J7320	Hyaluronan or derivitive, genvisc 850, for intra-articular injection, 1 mg
J7321	Hyaluronan or derivative, Hyalgan, Supartz or Visco-3, for intra-articular injection, per dose
J7322	Hyaluronan or derivative, hymovis, for intra-articular injection, 1 mg
J7323	Hyaluronan or derivative, Euflexxa, for intra-articular injection, per dose
J7324	Hyaluronan or derivative, Orthovisc, for intra-articular injection, per dose
J7325	Hyaluronan or derivative, Synvisc, or Synvisc-One for intra-articular injection, 1 mg
J7326	Hyaluronan or derivative, Gel-One, for intra-articular injection, per dose
J7327	Hyaluronan or derivative, Monovisc, for intra-articular injection, per dose
J7328	Hyaluronan or derivative, for intra-articular injection, 0.1 mg [Gel-Syn]
*Ultrasound guidance for vascular access*:
CPT codes covered if selection criteria are met:
+76937	Ultrasound guidance for vascular access requiring ultrasound evaluation of potential access sites, documentation of selected vessel patency, concurrent realtime ultrasound visualization of vascular needle entry, with permanent recording and reporting (List separately in addition to code for primary procedure)
76998	Ultrasonic guidance, intraoperative
CPT codes for procedures where 76937 and 76998 are covered if selection criteria are met (not all inclusive):
36555	Insertion of non-tunneled centrally inserted central venous catheter; younger than 5 years of age
36556	age 5 years or older
36557	Insertion of tunneled centrally inserted central venous catheter, without subcutaneous port or pump; younger than 5 years of age
36558	age 5 years or older
36560	Insertion of tunneled centrally inserted central venous access device, with subcutaneous port; younger than 5 years of age
36561	age 5 years or older
36563	Insertion of tunneled centrally inserted central venous access device with subcutaneous pump
36565	Insertion of tunneled centrally inserted central venous access device, requiring 2 catheters via 2 separate venous access sites; without subcutaneous port or pump (eg, Tesio type catheter)
36566	with subcutaneous port(s)
36570	Insertion of peripherally inserted central venous access device, with subcutaneous port; younger than 5 years of age
36571	age 5 years or older
36575	Repair of tunneled or non-tunneled central venous access catheter, without subcutaneous port or pump, central or peripheral insertion site
36576	Repair of central venous access device, with subcutaneous port or pump, central or peripheral insertion site
36578	Replacement, catheter only, of central venous access device, with subcutaneous port or pump, central or peripheral insertion site
36580	Replacement, complete, of a non-tunneled centrally inserted central venous catheter, without subcutaneous port or pump, through same venous access
36581	Replacement, complete, of a tunneled centrally inserted central venous catheter, without subcutaneous port or pump, through same venous access
36582	Replacement, complete, of a tunneled centrally inserted central venous access device, with subcutaneous port, through same venous access
36583	Replacement, complete, of a tunneled centrally inserted central venous access device, with subcutaneous pump, through same venous access
36585	Replacement, complete, of a peripherally inserted central venous access device, with subcutaneous port, through same venous access
36589	Removal of tunneled central venous catheter, without subcutaneous port or pump
36590	Removal of tunneled central venous access device, with subcutaneous port or pump, central or peripheral insertion
50040 - 50081	Incision, renal
50220 - 50240	Excision, renal
50384 - 50386	Introduction, renal
50390 - 50431, 50433, 50435	Other Introduction, renal
50541, 50543 - 50549	Laparoscopy, renal
50590 - 50593	Lithotripsy

The above policy is based on the following references:

Ali M, Mohamed A, Ahmed HE, et al. The use of ultrasound-guided platelet-rich plasma injections in the treatment of hip osteoarthritis: A systematic review of the literature. J Ultrason. 2018;18(75):332-337.
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Last Review 12/22/2021

Effective: 08/01/2019

Next Review: 10/13/2022
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