1. Aetna considers spinal manipulation under anesthesia (MUA) experimental and investigational. This procedure has not been established as either safe or effective for the treatment of musculoskeletal disorders such as neck and back problems. Critical issues such as selection criteria, outcome assessments, and long-term benefits need to be addressed by well-designed studies before this procedure can be considered as an essential part of conservative therapy. In this regard, the Guidelines for Chiropractic Quality Assurance and Practice Parameters published from the proceedings of a consensus conference commissioned by the Congress of Chiropractic State Associations declared that chiropractic involvement in manipulation under anesthesia is a new area of special interest that needs further investigation.

2. Aetna considers MUA medically necessary for the following indications:

   1. Frozen shoulder (adhesive capsulitis); or

   2. Arthrofibrosis of knee following total knee arthroplasty , knee surgery, or fracture in persons having less than 90 degrees range of motion six or more weeks after surgery or trauma.

3. Aetna considers MUA for disorders of other body joints (e.g., pelvis and hip, ankle, elbow, wrist, and temporomandibular joint) experimental and investigational because there is insufficient evidence to support this approach.

Note: This policy is not intended to apply to examinations under anesthesia, or to setting fractures or complete joint dislocations under anesthesia.

Spinal manipulation under anesthesia (SMUA) has been used mostly by osteopaths and to a much lesser degree by orthopedists to treat spinal dysfunction. This procedure was typically performed in one single session. More recently, some chiropractors, with the assistance of anesthesiologists, have also employed this technique to alleviate acute and chronic neck and back pain.

The rationale for this approach is that fibrotic changes in the peri-articular and intra-articular soft tissues hinder movement, and sometimes it is necessary to anesthetize patients to reduce muscle tone and protective reflex mechanisms so that the spine can be manipulated effectively. This maneuver supposedly will break up adhesions within the surrounding spinal joints and stretch the restricting fibrotic tissue to a length compatible with motion, thereby, increasing joint function and reducing pain.

Within the realm of chiropractic, SMUA is generally performed daily for 1 to 5 consecutive days on an outpatient basis, and is followed by a post-SMUA rehabilitation regimen, which entails one week of daily manipulation to maintain joint mobility and avoid re-adhesion of fibrotic tissue. Anesthesia is usually induced by intravenous Pentothal (sodium thiopental), and manipulation of the affected joints takes about 7 to 10 minutes.

Although the risks associated with spinal manipulation and SMUA appear remote, serious complications following lumbar spinal manipulation, including massive cauda equina compression and vertebral pedicle fracture have been reported. For manipulation of the cervical spine, there is an increased chance of basivertebral and/or vertebral artery injury. Additionally, general anesthesia carries a small but clinically significant risk of anaphylaxis or malignant hyperpyrexia.

A recent assessment on SMUA (Kohlbeck and Haldeman, 2002) concluded that medicine assisted spinal manipulation therapies have a relatively long history of clinical use and have been reported in the literature for over 70 years. However, evidence for the effectiveness of these protocols remains largely anecdotal, based on case series mimicking many other surgical and conservative approaches for the treatment of chronic pain syndromes of musculoskeletal origin. There is, however, sufficient theoretical basis and positive results from case series to warrant further controlled trials on these techniques.

In a prospective cohort study of 68 chronic low-back pain (LBP) patients. Kohlbeck et al (2005) measured changes in pain and disability for LBP patients receiving treatment with medication-assisted manipulation (MAM) and compared these to changes in a group only receiving spinal manipulation therapy (SMT). Outcomes were measured using the 1998 Version 2.0 American Association of Orthopaedic Surgeons/Council of Musculoskeletal Specialty Societies/Council of Spine Societies Outcomes Data Collection Instruments. The primary outcome variable was change in pain and disability. All patients received an initial 4- to 6-week trial of SMT, after which 42 patients received supplemental intervention with MAM and the remaining 26 patients continued with SMT. Low back pain and disability measures favored the MAM group over the SMT-only group at 3 months. This difference attenuated at 1 year. These investigators concluded that medication-assisted manipulation appears to offer some patients increased improvement in LBP and disability, and stated that further investigation of these apparent benefits in a randomized clinical trial is warranted.

Manipulation under anesthesia (MUA) has been used for refractory cases of frozen shoulder (adhesive capsulitis) (Dias, et al., 2005). A systematic review in BMJ Clinical Evidence (Speed, 2006) found that MUA plus intraarticular injection is "likely to be beneficial" for persons with frozen shoulder. The conclusions were based upon the results of two randomized controlled clinical trials. One randomized controlled clinical trial (n = 30) found that, in people with adhesive capsulitis, manipulation under anesthesia plus intra-articular hydrocortisone injection increased recovery rates compared with intra-articular hydrocortisone injection alone at 3 months (Thomas, et al., 1980). Another, weaker randomized controlled clinical trial (n = 98) found limited evidence that more people having manipulation under anesthesia plus intra-articular saline injection than having manipulation alone or manipulation plus intra-articular injection of methylprednisolone had improvements in range of movement, pain relief, and return to normal activities (Hamdan & Al Essa, 2003). The review noted that potential adverse effects of manipulation under anesthesia of the shoulder include intra-articular lesions within the glenohumeral joint (Speed, 2006).

In a Cochrane review, Green et al (2000) examined the effectiveness of common interventions for shoulder pain.  Intervention of interest included non-steroidal anti-inflammatory drugs, intra-articular or subacromial glucocorticosteroid injection, oral glucocorticosteroid treatment, physiotherapy, MUA, hydrodilatation, or surgery.  The authors concluded that there is little evidence to support or refute the effectiveness of common interventions for shoulder pain.  They stated that there is a need for further well-designed clinical trials to establish a uniform method of defining shoulder disorders and developing outcome measures which are valid, reliable and responsive in these study populations.

Quraishi et al (2007) assessed the outcome of MUA and hydrodilatation as treatments for adhesive capsulitis.  A total of 36 patients (38 shoulders) were randomized to receive either method, with all patients being treated in stage II of the disease process.  The mean age of the patients was 55.2 years (44 to 70) and the mean duration of symptoms was 33.7 weeks (12 to 76).  A total of 18 shoulders (17 patients) received MUA  and 20 (19 patients) received hydrodilatation.  There were 3 insulin-dependent diabetics in each group.  The mean visual analog score (VAS) in the MUA group was 5.7 (3 to 8.5; n = 18) before treatment, 4.7 (0 to 8.5; n = 16) at 2 months (paired t-test p = 0.02), and 2.7 (0 to 9; n = 16) at 6 months (paired t-test, p = 0.0006).  The mean score in the hydrodilatation group was 6.1 (4 to 10; n = 20) before treatment, 2.4 (0 to 8; n = 18) at 2 months (paired t-test, p = 0.001), and 1.7 (0 to 7; n = 18) at 6 months (paired t-test, p = 0.0006).  The VAS in the hydrodilatation group were significantly better than those in the MUA group over the 6-month follow-up period (p < 0.0001).  The mean Constant score in those manipulated was 36 (26 to 66) before treatment, 58.5 (24 to 90) at 2 months (paired t-test, p = 0.001) and 59.5 (23 to 85) at 6 months (paired t-test, p = 0.0006).  In the hydrodilatation group it was 28.8 (18 to 55) before treatment, 57.4 (17 to 80) at 2 months (paired t-test, p = 0.0004) and 65.9 (28 to 92) at 6 months (paired t-test, p = 0.0005).  The Constant scores in the hydrodilatation group were significantly better than those in the MUA group over the 6-month period of follow-up (p = 0.02).  The range of motion improved in all patients over the 6 months, but was not significantly different between the groups.  At the final follow-up, 94 % of patients (17 of 18) were satisfied or very satisfied after hydrodilatation compared with 81 % (13 of 16) of those who received MUA.  Most patients were treated successfully, but those undergoing hydrodilatation did better than those who underwent MUA.

Kivimäki and colleagues (2007) examined the effect of MUA in patients with frozen shoulder.  A blinded randomized trial with a 1-year follow-up was performed at 3 referral hospitals.  A total of 125 patients with clinically verified frozen shoulder were randomly assigned to the manipulation group (n = 65) or control group (n = 60).  Both the intervention group and the control group were instructed in specific therapeutic exercises by physiotherapists.  Clinical data were gathered at baseline and at 6 weeks and 3, 6, and 12 months after randomization.  The 2 groups did not differ at any time of the follow-up in terms of shoulder pain or working ability.  Small differences in the range of motiont were detected favoring the manipulation group.  Perceived shoulder pain decreased during follow-up equally in the 2 groups, and at 1 year after randomization, only slight pain remained.  Manipulation under anesthesia does not add effectiveness to an exercise program performed by patients.

Flannery et al (2007) examined the influence of timing of MUA for adhesive capsulitis of the shoulder on the long-term outcome.  A total of 180 consecutive patients with a diagnosis of adhesive capsulitis according to Codman's criteria were selected from a shoulder surgery database; 145 were available for follow-up after a mean period of 62 months (range of 12 to 125).  All patients underwent MUA with intra-articular steroid injection.  A statistically significant improvement in range of movement, function (Oxford Shoulder Score) (OSS) and VAS was obtained following manipulation.  Ninety percent of the 145 patients who successfully completed the study were satisfied with the procedure; 89 % indicated that they would choose the same procedure again if the same problem arose in the opposite shoulder.  Eighty-three percent of the patients had MUA performed less than 9 months from onset of symptoms (early MUA).  The remainder had MUA performed after 9 to 40 months (late MUA).  Patients who had early intervention had a significantly better Oxford Shoulder Score at final follow-up; mobility and pain were also letter than in the late MUA group, but not significantly.

Manipulation under anesthesia has also been used to treat fibroarthrosis following total knee replacement.  Following total knee arthroplasty, some patients who fail to achieve greater than 90 degrees of flexion in the early perioperative period may be considered candidates for MUA of the knee.  Manipulation under anesthesia is indicated in total knee arthroplasty having less than 90 degrees range of motion after six weeks, with no progression or regression in range of motion (Pariente, et al., 2006).

Keating, et al. (2007) assessed the outcomes of manipulation following total knee arthroplasty. One hundred and thirteen knees in ninety patients underwent manipulation for postoperative flexion of greater than or equal to 90 degrees at a mean of ten weeks after surgery. Eighty-one (90 %) of the ninety patients achieved improvement of ultimate knee flexion following manipulation. The average flexion was 102 degrees prior to total knee arthroplasty, 111 degrees following skin closure, and 70 degrees before manipulation. The average improvement in flexion from the measurement made before manipulation to that recorded at the 5-year follow-up was 35 degrees (p < 0.0001). The investigators reported that there was no significant difference in the mean improvement in flexion when patients who had manipulation within 12 weeks postoperatively were compared with those who had manipulation more than 12 weeks postoperatively. Patients who eventually underwent manipulation had significantly lower preoperative Knee Society pain scores (more pain) than those who had not had manipulation (p = 0.0027). The investigators concluded that manipulation generally increases ultimate flexion following total knee arthroplasty. They noted that patients with severe preoperative pain are more likely to require manipulation.

Available evidence for manipulation under anesthesia for temporomandibular joint syndrome is limited to small, uncontrolled studies with limited follow-up. Foster, et al. (2000) conducted an uncontrolled prospective study of manipulation of the temporomandibular joint under anesthesia. The investigators reported that, of the 55 patients invited to participate in this study, 15 improved, 15 did not, 6 showed partial improvement, and 19 were not treated. The median pre-treatment opening was 20mm (range 13-27). Among those who improved after manipulation, the median opening after treatment was 38mm (range 35-56). The investigators reported that some of those who improved experienced a return of TMJ clicking but not of joint or muscle tenderness.

There is a paucity of evidence supporting the use of MUA for the treatment of disorders of other body joints such as the hip, ankle, knee, and wrist.