Aetna considers extracorporeal shock-wave therapy (ESWT) experimental and investigational for the following indications (not an all inclusive list) because there is insufficient evidence of effectiveness of ESWT for these indications in the medical literature:

• Achilles tendonitis
• Delayed unions
• Erectile dysfunction
• Lateral epicondylitis (tennis elbow)
• Low back pain
• Non-unions
• Osteonecrosis of the femoral head
• Peyronie's disease
• Rotator cuff tendonitis (shoulder pain)
• Stress fractures
• Wound healing (including burn wounds)
• Other musculoskeletal indications.

See also CPB 0235 - Plantar Fasciitis Treatments.

Lateral elbow pain (tennis elbow, lateral epicondylitis, rowing elbow) is one of the most commonly encountered repetitive motion injuries; the prevalence of lateral elbow pain in the population has been estimated to be 1 to 3 %.  Symptoms often persist for 18 months to 2 years and a small proportion of patients eventually undergo surgery.

This overuse syndrome is caused by continued stress on the grasping muscles (extensor carpi radialis brevis and longus) and supination muscles (supinator longus and brevis) of the forearm, which originate on the lateral epicondyle of the elbow.

Conservative treatment involves rest, ice, stretching, strengthening, and lower intensity to allow for maladaptive change.  Any activity that hurts on extending or pronating the wrist should be avoided.  With healing, exercises to strengthen the wrist extensors can be started.  Generally, exercises to strengthen the wrist flexor pronators are also recommended.

The mechanism of action of extracorporeal shock wave therapy in the treatment of lateral elbow pain is not well understood.  Techniques for using extracorporeal shock wave therapy for musculoskeletal problems have not yet been standardized and the precise dosages and the optimal frequency of application have not been studied extensively.  There is still no consensus on when to differentiate between low- and high-energy shock wave applications.  Other outstanding issues include whether the shock waves should be directed to the target area by radiological or ultrasound imaging, and whether local anesthetic injections should be used in the target area prior to treatment to reduce painful reactions.

A systematic review of ESWT for lateral epicondylitis has been published by Buchbinder et al (2005).  The investigators identified 9 randomized controlled clinical trials trials of ESWT versus placebo for lateral epicondylitis.  Five of the studies showed that pain, function and grip strength was the same or slightly more improved with shock wave therapy than with placebo.  Four studies demonstrated more improvement with shock wave therapy than placebo therapy.  When Buchbinder et al (2005) pooled the data from the 9 trials, they found no statistically significant benefit of ESWT for lateral epicondylitis.  The investigators concluded that "[b]ased upon systematic review of nine placebo-controlled trials involving 1006 participants, there is 'Platinum' level evidence that shock wave therapy provides little or no benefit in terms of pain and function in lateral elbow pain."

In a randomized controlled study (n = 60), Chung and Wiley (2004) concluded that despite improvement in pain scores and pain-free maximum grip strength within groups, there does not appear to be a meaningful difference between treating lateral epicondylitis with ESWT combined with forearm-stretching program and treating with forearm-stretching program alone, with respect to resolving pain within an 8-week period of commencing treatment.  Stasinopoulos and Johnson (2005) stated that more research with well-designed randomized control studies is needed to establish the absolute and relative effectiveness of ESWT for tennis elbow.  Furthermore, in a systematic review and meta-analysis of clinical trials on physical interventions for lateral epicondylalgia, Bisset et al (2005) stated that ESWT is not beneficial in the treatment of tennis elbow.

An assessment from the BlueCross BlueShield Association Technology Evaluation Center (2005) concluded that ESWT for lateral epicondylitis does not meet the TEC criteria.  The assessment explained that "[o]verall, the available data does not provide strong and consistent evidence that ESWT improves outcomes of chronic lateral epicondylitis." 

Medial epicondylitis (golfers elbow) is an overuse injury affecting the flexor-pronator muscle origin at the anterior medial epicondyle of the humerus.  Medial epicondylitis is similar to the more common lateral epicondylitis in many respects.  Both conditions are overuse tendinopathies that can be associated with racquet sports.  Other activities with which medial epicondylitis is associated include golfing, throwing sports, and racquet sports.  This condition also has been reported in bowlers, archers, and weightlifters.  Pain worsens with wrist flexion and pronation activities.  Patients may report discomfort even when simply shaking hands with someone.  History of an acute injury may be reported (e.g., taking a divot in golf, throwing a pitch in baseball, a hard serve in tennis).  Up to 50 % of patients with medial epicondylitis complain of occasional or constant numbness and/or tingling sensation that radiates into their fourth and fifth fingers, suggesting involvement of the ulnar nerve.

An early study of ESWT for medial epicondylitis reported disappointing results (Krischek et al, 2001).  This is confirmed by two randomized controlled studies.  Haake and associates (2002) concluded that ESWT was ineffective in the treatment of lateral epicondylitis (n = 272).  The previously reported success of this therapy appears to be attributable to inappropriate study designs. 

Melikyan et al (2003) reported on the results of a double-blind randomized controlled clinical study of ESWT in 74 patients with epicondylitis.  The investigators reported no significant differences between treatment and placebo groups in improvements in pain, function or disability.  The investigators concluded that "[o]ur study showed no evidence that extracorporeal shock-wave therapy for tennis elbow is better than placebo."  A systematic evidence review concluded that the effectiveness of ESWT for tennis elbow is "unknown" (Assendelft et al, 2003).

An assessment of ESWT for refractory tennis elbow by the National Institute for Clinical Excellence (NICE, 2009) concluded that, although the evidence on extracorporeal shockwave therapy for refractory tennis elbow raises no major safety concerns, the evidence on its efficacy is inconsistent.  "Therefore, this procedure should only be used with special arrangements for clinical governance, consent and audit or research."

The Canadian Agency for Drugs and Technologies in Health (CADTH)'s report on ESWT for chronic lateral epicondylitis (Ho, 2007a) stated that "the lack of convincing evidence regarding its effectiveness does not support the use of ESWT for chronic lateral epicondylitis."  The CADTH's report on ESWT for chronic rotator cuff tendonitis (Ho, 2007b) stated that "the evidence reviewed for this bulletin supports the use of high-energy ESWT for chronic calcific rotator cuff tendonitis, but not for non-calcific rotator cuff tendonitis.  High-quality randomized controlled trials (RCTs) with larger sample sizes are needed to provide stronger evidence."

Extracorporeal shock wave therapy has also been studied in other musculoskeletal applications, including Achilles tendonitis and shoulder tendonitis.  Published articles on ESWT for Achilles tendonitis have been limited to studies using animal models.  There are no adequate prospective clinical studies demonstrating the effectiveness of ESWT for Achilles tendonitis.  Guidance from the National Institute for Health and Clinical Excellence (NICE, 2009) concluded that although the evidence on extracorporeal shockwave therapy for refractory Achilles tendinopathy raises no major safety concerns, evidence on efficacy of the procedure is inconsistent.  "Therefore, ESWT for refractory Achilles tendinopathy should only be used with special arrangements for clinical governance, consent and audit or research." 

Extracorporeal shock wave therapy has also been used for the treatment of shoulder pain (calcific tendonitis of the shoulder).  In a review on ESWT for the treatment of calcific and non-calcific tendonitis of the rotator cuff, Harniman et al (2004) found that common problem associated with this research area were sample size, randomization, blinding, treatment provider bias, and outcome measures.  The investigators found moderate evidence that high-energy ESWT is effective in treating chronic calcific rotator cuff tendonitis when the shock waves are focused at the calcified deposit.  Additionally, the investigators found moderate evidence that low-energy ESWT is not effective for treating chronic non-calcific rotator cuff tendonitis, although this conclusion is based on only one high-quality study, which was underpowered.  These investigators concluded that high-quality randomized, controlled trials with larger sample sizes, better randomization and blinding, and better outcome measures are needed to ascertain the effectiveness of ESWT for calcific and non-calcific tendonitis of the rotator cuff.

An assessment of extracorporeal shock wave therapy conducted by the Washington State Department of Labor and Industries (2003) concluded that "the evidence establishing the effectiveness [of ESWT] for musculoskeletal conditions remains inconclusive".  In a review on plantar fasciitis, Buchbinder (2004) stated that "ESWT has been proposed as an alternative approach on the grounds that it may stimulate healing of soft tissue and inhibit pain receptors.  However, the available data do not provide substantive support for its use".

An assessment prepared for the Ohio Bureau of Workers' Compensation (2005) concluded that "[s]tudies have not demonstrated consistent results or efficacy in the treatment of plantar fasciitis, epicondylitis, and noncalcific tendonitis of the shoulder.  ESWT is considered unproven and investigational for these services."  The assessment noted that although "[u]se of ESWT in the treatment of x-ray confirmed calcific tendonitis of the shoulder shows preliminary good results", that "[r]eplication of the results with additional studies would be beneficial prior to acceptance."

In a single-blind, randomized, controlled trial, Engebretsen et al (2011) evaluated the results of radial ESWT (rESWT) and supervised exercises (SE) provided to patients with subacromial shoulder pain after 1 year.  A total of 104 patients with subacromial shoulder pain lasting at least 3 months were included in this study.  Patients were randomly assigned to either an rESWT group (n = 52) or an SE group (n = 52).  The rESWT intervention consisted of 1 session weekly for 4 to 6 weeks.  The SE intervention consisted of 2 45-min sessions per week for up to 12 weeks.  The primary outcome measure was the Shoulder Pain and Disability Index.  Secondary outcome measures were questions regarding pain and function and work status.  After 1 year, an intention-to-treat analysis showed no significant differences between the 2 groups for the primary outcome measure (-7.6 points, 95 % confidence interval [CI]: -16.6 to 0.5) and pain, function, and medication use.  Twenty-nine participants (60 %) in the SE group versus 24 participants (52 %) in the rESWT group were categorized as clinically improved.  Thirty-eight participants in the SE group were at work compared with 30 participants in the rESWT group (odds ratio = 1.1, 95 % CI: 1.0 to 1.2).  Fewer patients in the SE group had received additional treatments between 18 weeks and 1 year.  The authors concluded that no significant difference was found between the SE and rESWT groups at the 1-year follow-up.  More participants in the SE group had returned to work.

In the last decade, ESWT has become a common tool for the treatment of non-unions.  Rompe et al (2001) reported that although high-energy shock wave therapy seemed to be an effective non-invasive tool for stimulation of bone healing in properly selected patients with a diaphyseal or metaphyseal nonunion of the femur or tibia, additional controlled studies are mandatory.  In a review on the use of ESWT in the treatment of non-unions, Birnbaum et al (2002) stated that presently ESWT is not yet a standard therapeutic technique in orthopedics.  These investigators concluded that the primary aim of further research should be the evaluation of adequate energy density levels and impulse rates for various indications in accordance with evidence-based medicine.  Well-designed studies with long-term follow-ups are need before ESWT can be compared with established methods.

Biedermann et al (2003) stated that nonunion remains a major complication after skeletal trauma.  However, to date, no prospective, randomized trial has been conducted to show the efficacy of this form of treatment.  The authors concluded that no evidence supports the treatment of pseudarthroses with ESWT.  A randomized, prospective, clinical trial with a control group has to be performed before a final decision can be made regarding this indication for ESWT.  An assessment prepared for the Ohio Bureau of Workers' Compensation (2004) concluded that additional studies of ESWT in non-unions are needed.

Available brands of ESWT devices include the OssaTron (HealthTronics, Marietta, GA), the Dornier Epos Ultra (Dornier Medical Systems, Kennesaw, GA), and the Sonocur (Siemens Medical Solutions Inc., Iselin, NJ).

Seil et al (2006) stated that shock waves, as applied in urology and gastroenterology, were introduced in the middle of the last decade in Germany to treat different pathologies of the musculoskeletal system, including epicondylitis of the elbow, plantar fasciitis, and calcifying and non-calcifying tendinitis of the rotator cuff.  With the non-invasive nature of these waves and their seemingly low complication rate, ESWT seemed a promising alternative to the established conservative and surgical options in the treatment of patients with chronically painful conditions.  However, the apparent advantages of the method led to a rapid diffusion and even inflationary use of ESWT.  The authors noted that prospective, randomized studies on the mechanisms and effects of shock waves on musculoskeletal tissues are urgently needed to define more accurate indications and optimize therapeutic outcome.

In a double-blind, randomized, placebo-controlled study, Staples et al (2008) examined if ultrasound-guided ESWT reduced pain and improved function in patients with lateral epicondylitis (tennis elbow) in the short-term and intermediate-term.  A total of 68 patients from community-based referring doctors were randomized to receive 3 ESWT treatments or 3 treatments at a sub-therapeutic dose given at weekly intervals.  Seven outcome measures relating to pain and function were collected at follow-up evaluations at 6 weeks, 3 months, and 6 months after completion of the treatment.  The mean changes in outcome variables from baseline to 6 weeks, 3 months, and 6 months were compared for the 2 groups.  The groups did not differ on demographical or clinical characteristics at baseline and there were significant improvements in almost all outcome measures for both groups over the 6-month follow-up period, but there were no differences between the groups even after adjusting for duration of symptoms.  The authors concluded that these findings provided little evidence to support the use of ESWT for the treatment of lateral epicondylitis and is in keeping with recent systematic reviews of ESWT for lateral epicondylitis that have drawn similar conclusions.

In a review on the treatment of epicondylitis, Schleicher et al (2010) noted that the choice of different treatments is hard to overlook and there are only a few good clinical trials that supported one treatment option by means of evidence based medicine.  During the acute phase, topical non-steroidal anti-inflammatory drugs, steroid injections, ultrasound and acupuncture are helpful.  There is no consensus about the effectiveness of physiotherapy, orthoses, laser, electrotherapy or botulinum toxin injections.  During the chronic phase, none of the different treatment modalities is effective according to criteria of evidence-based medicine.  By now, it has not been proven whether patients profit during that time of physiotherapy, orthoses, ESWT or an operation.

Hearnden and colleagues (2009) stated that ESWT has been claimed to be an effective non-invasive treatment for chronic calcific tendonitis of the supra-spinatus tendon.  However, many trials have been criticised for not achieving necessary scientific standards.  In a prospective, single-blinded, randomized control trial of 20 patients, these investigators examined the effectiveness of the therapy.  Subjectively, 45 % of the treated patients were satisfied with the outcome and also had objectively increased their Constant score by 11 % at 6 months.  The control group experienced no subjective or objective improvement (p < 0.03).  This study confirmed that ESWT is effective in treating chronic calcific tendonitis when compared with a placebo group.  However, in the authors' experience it is not as successful as previously claimed, with 50 % of the patients failing to achieve a satisfactory outcome and requiring surgical excision.  Moreover, patients found the procedure painful, which has not been alluded to previously.

Schaden et al (2007) evaluated the feasibility and safety of ESWT for acute and chronic soft-tissue wounds.  A total of 208 patients with complicated, non-healing, acute and chronic soft tissue wounds were prospectively enrolled onto this trial.  Treatment consisted of debridement, out-patient ESWT [100 to 1000 shocks/cm(2) at 0.1 mJ/mm(2), according to wound size, every 1 to 2 week over a mean of 3 treatments], and moist dressings.  Thirty-two (15.4 %) patients dropped out of the study following first ESWT and were analyzed on an intent-to-treat basis as incomplete healing.  Of 208 patients enrolled, 156 (75 %) had 100 % wound epithelialization.  During mean follow-up period of 44 days, there was no treatment-related toxicity, infection, or deterioration of any ESWT-treated wound.  Intent-to-treat multi-variate analysis identified age (p = 0.01), wound size less than or equal to 10 cm(2) (p = 0.01; OR = 0.36; 95 % CI: 0.16 to 0.80), and duration less than or equal to 1 month (p < 0.001; OR = 0.25; 95 % CI: 0.11 to 0.55) as independent predictors of complete healing.  The authors concluded that the ESWT strategy is feasible and well-tolerated by patients with acute and chronic soft tissue wounds.  They noted that ESWT is being evaluated in a phase III trial for acute traumatic wounds.

Alves et al (2009) stated that osteonecrosis is a progressive clinical condition with significant morbidity, which primarily affects weight-bearing joints and is characterized by the death of the bone, or part of it, because of insufficient circulation.  The hip is the most common compromised joint.  In osteonecrosis of the femoral head (ONFH), the collapse of the femoral head is a result of mechanically weak bone submitted to a load of weight, and can be associated with incapacitating pain and immobility.  Both surgical as well as non-surgical options have been used with differing levels of success, and non-operative treatment modalities such as bisphosphonates, statins, anti-coagulants, and ESWT for early-stage disease have been described, but exact indications have not been established yet.  The aim of this study was to make a systematic review of the use of ESWT in the treatment of ONFH.  Medline, Lilacs, and Scielo databases were searched using the keywords "shock wave", "osteonecrosis", "avascular necrosis", "aseptic necrosis" and "femoral head".  The search period was between 1966 and 2009.  Only 5 articles that fulfilled the previously established criteria were obtained.  Of these 5 articles, 2 were RCTs, 1 open label study, 1 comparative prospective study, and 1 was a case report.  This review demonstrated that there are no controlled and double-blind studies about the efficacy of ESWT in the treatment of ONFH.  On the other hand, the published non-controlled studies appear to demonstrate some favorable result, which justifies new research in this area.

Larking and associates (2010) examined if ESWT increases the rate of healing in patients with chronic neurological conditions and chronic decubitus ulceration.  Ulcers were randomized into receiving either the ESWT or the placebo for a 4-week period, followed by a 2-week "washout" period followed by a 4-week period of the cross-over treatment/placebo.  Main outcome measure was measurement of the area of the ulceration.  For each observation the average of 3 measurements were taken.  A total of 9 ulcers (in 8 patients) were included in the study: 5 on the buttocks/sacrum/trochanter and 4 on the feet/ankles.  All those with static chronic ulcers showed improved healing starting 6 to 8 weeks after the start of ESWT, whether treated first with the placebo or the therapy.  The authors concluded that ESWT has a potential part to play in the treatment of chronic skin ulceration.  The findings of this small study need to be validated by well-designed studies.

Zelle and colleagues (2010) provided a concise review of the basic science of ESWT and performed a systematic review of the literature for the use of ESWT in the treatment of fractures and delayed unions/non-unions.  Articles in the English or German language were identified for the systematic review by searching PubMed-Medline from 1966 until 2008, Cochrane database of systematic reviews, Cochrane database of abstracts of reviews of effects, Cochrane central register of controlled trials, and relevant meeting abstracts from 2007 to 2008.  Moreover, the bibliographies of the identified articles were reviewed.  These investigators included clinical outcome studies of ESWT in the treatment of fractures and delayed unions/non-unions.  Reports with less than 10 patients were excluded.  Non-unions after corrective osteotomies or arthrodeses were excluded.  Sample size, level of evidence, definition of delayed union, definition of non-union, time from injury to shock wave treatment, location of fracture, union rate, and complications were extracted from the identified articles.  Data of 924 patients undergoing ESWT for delayed union/non-union were extracted from 10 studies.  All articles were graded as level 4 studies.  The overall union rate was 76 % (95 % CI: 73 % to 79 %).  The union rate was significantly higher in hypertrophic non-unions than in atrophic non-unions.  The authors conclued that data from level 4 studies suggested that ESWT seems to stimulate the healing process in delayed unions/non-unions.  However, they stated that further investigations are needed.

Interventional procedure consultation from the National Institute for Health and Clinical Excellence (NICE, 2011) concluded that evidence of the safety and efficacy of ESWT for greater trochanteric pain syndrome is of limited quality and quantity. The guidance stated that NICE encourages further research into ESWT for refractory greater trochanteric pain syndrome. Research studies should clearly describe patient selection, imaging, and treatment protocols. Outcomes should include functional and quality-of-life scores with at least 1 year of follow-up. 

Rompe et al (2009) reported on a comparative study involving 229 subjects with refractory unilateral greater trochanter pain syndrome who were assigned sequentially to a home training program, a single local corticosteroid injection (25 mg prednisolone), or a repetitive low-energy radial shock wave treatment.  Subjects underwent outcome assessments at baseline and at 1, 4, and 15 months.  Primary outcome measures were degree of recovery, measured on a 6-point Likert scale (subjects with rating completely recovered or much improved were rated as treatment success), and severity of pain over the past week (0 to 10 points) at 4-month follow-up.  One month from baseline, results after corticosteroid injection (success rate, 75 %; pain rating, 2.2 points) were significantly better than those after home training (7 %; 5.9 points) or shock wave therapy (13 %; 5.6 points).  Regarding treatment success at 4 months, radial shock wave therapy led to significantly better results (68 %; 3.1 points) than did home training (41 %; 5.2 points) and corticosteroid injection (51 %; 4.5 points).  Fifteen months from baseline, radial shock wave therapy (74 %; 2.4 points) and home training (80 %; 2.7 points) were significantly more successful than was corticosteroid injection (48 %; 5.3 points).  The authors reported that the significant short-term superiority of a single corticosteroid injection over home training and shock wave therapy declined after 1 month.  The authors reported that both corticosteroid injection and home training were significantly less successful than was shock wave therapy at 4-month follow-up.  Corticosteroid injection was significantly less successful than was home training or shock wave therapy at 15-month follow-up.

In a prospective, randomized, controlled trial, Chitale et al (2010) compared limited ESWT versus sham therapy in men with Peyronie's disease.  A total of 36 men were randomized to 6 sessions of ESWT or sham treatment.  Geometrical measurements of penile length and deformity, and the abridged International Index of Erectile Function (IIEF) score and visual analog score (VAS) were recorded and re-evaluated at 6 months.  The patient and assessor were unaware of the treatment type.  Standard non-parametric tests were used for the statistical analysis.  A full set of outcome data was obtained for 16 patients in the intervention group and 20 in the sham/control group (mean age of 58 and 60 years; mean duration of symptoms of 15 and 33 months, respectively).  There was no significant difference in the mean change between the control and intervention groups on any outcome measure.  There were improvements in the mean (S.D.) dorsal and lateral angle, of 5.3 (11.66) degrees and 3.5 (17.38) degrees in the control group, and a deterioration of 0.9 (16.01)degrees and 0.9 (15.56) degrees in the ESWT group.  Mean improvements in curved and straight lengths were 0.2 (0.58) and 0.1 (0.8) cm in the control and mean reductions of 0.1 (0.9) and 0.1 (1.49) cm in the ESWT group.  The mean changes in the IIEF and VAS scores were 0.1 (3.32) and -0.8 (1.77) for control and 0.56 (2.6) and -1.05 (1.79) for ESWT group.  The authors concluded that there were no significant differences in changes of variables in Peyronie's disease treated with short-term ESWT.

In a systematic review, Seco et al (2011) evaluated the evidence on the efficacy, effectiveness, cost-effectiveness, and safety of ultrasound and shock wave to treat low back pain (LBP).  An electronic search was performed in MEDLINE, EMBASE, and the Cochrane Library databases up to July 2009 to identify RCTs comparing vibrotherapy with placebo or with other treatments for LBP.  No language restrictions were applied.  Additional data were requested from the authors of the original studies.  The risk of bias of each study was assessed following the criteria recommended by the Cochrane Back Review Group.  A total of 13 studies were identified.  The 4 RCTs complying with the inclusion criteria included 252 patients; 2 of the 3 RCTs on ultrasound had a high-risk of bias.  For acute patients with LBP and leg pain attributed to disc herniation, ultrasound, traction, and low-power laser obtained similar results.  For chronic LBP patients without leg pain, ultrasound was less effective than spinal manipulation, whereas a shock wave device and transcutaneous electrical nerve stimulation led to similar results.  Results from the only study comparing ultrasound versus a sham procedure are unreliable because of the inappropriateness of the sham procedure, low sample size, and lack of adjustment for potential confounders.  No study assessed cost-effectiveness; no adverse events were reported.  The authors concluded that available evidence does not support the effectiveness of ultrasound or shock wave for treating LBP.  They stated that high-quality RCTs are needed to assess their efficacy versus appropriate sham procedures, and their effectiveness and cost-effectiveness versus other procedures shown to be effective for LBP.  In the absence of such evidence, the clinical use of these forms of treatment is not justified and should be discouraged.

In a phase II clinical study, Ottomann et al (2012) examined shock wave effects in burn wounds.  A pre-defined cohort of 50 patients (6 with incomplete data or lost to follow-up) with acute second-degree burns from a larger study of 100 patients were randomly assigned between December 2006 and December 2007 to receive standard therapy (burn wound debridement/topical anti-septic therapy) with (n = 22) or without (n = 22) defocused ESWT (100 impulses/cm at 0.1 mJ/mm) applied once to the study burn, after debridement.  Randomization sequence was computer-generated, and patients were blinded to treatment allocation.  The primary endpoint, time to complete burn wound epithelialization, was determined by independent, blinded-observer.  A worst case scenario was applied to the missing cases to rule out the impact of withdrawal bias.  Patient characteristics across the 2 study groups were balanced (p > 0.05) except for older age (53 +/- 17 versus 38 +/- 13 years, p = 0.002) in the ESWT group.  Mean time to complete (greater than or equal to 95 %) epithelialization (CE) for patients that did and did not undergo ESWT was 9.6 +/- 1.7 and 12.5 +/- 2.2 days, respectively (p < 0.0005).  When age (continuous variable) and treatment group (binary) were examined in a linear regression model to control the baseline age imbalance, time to CE, age was not significant (p = 0.33) and treatment group retained significance (p < 0.0005).  Statistical significance (p = 0.001) was retained when ESWT cases with missing follow-up were assigned the longest time to CE and when controls with missing follow-up were assigned the shortest time to CE.  The authors concluded that in this randomized phase II study, application of a single defocused shock wave treatment to the superficial second-degree burn wound after debridement/topical anti-septic therapy significantly accelerated epithelialization.  They stated that this finding warrants confirmation in a larger phase III trial.  Drawbacks of this study included absence of burn wound histology, modest sample size, and lack of long-term follow-up. 

Vardi and colleagues (2012) examined the clinical and physiological effect of low-intensity ESWT on men with organic erectile dysfunction who are phosphodiesterase type 5 inhibitor responders.  After a 1-month phosphodiesterase type 5 inhibitor wash-out period, 67 men were randomized in a 2:1 ratio to receive 12 sessions of low-intensity ESWT or sham therapy.  Erectile function and penile hemodynamics were assessed before the first treatment (visit 1) and 1 month after the final treatment (follow-up 1) using validated sexual function questionnaires and veno-occlusive strain gauge plethysmography.  Clinically, these investigators found a significantly greater increase in the International Index of Erectile Function-Erectile Function domain score from visit 1 to follow-up 1 in the treated group than in the sham-treated group (mean +/- SEM 6.7 +/- 0.9 versus 3.0 +/- 1.4, p = 0.0322).  There were 19 men in the treated group who were initially unable to achieve erections hard enough for penetration (Erection Hardness Score 2 or less) who were able to achieve erections sufficiently firm for penetration (Erection Hardness Score 3 or greater) after low-intensity ESWT, compared to none in the sham group.  Physiologically penile hemodynamics significantly improved in the treated group but not in the sham group (maximal post-ischemic penile blood flow 8.2 versus 0.1 ml/min/dL, p < 0.0001).  None of the men experienced discomfort or reported any adverse effects from the treatment.  The authors concluded that this is the first randomized, double-blind, sham controlled study to their knowledge that shows that low-intensity ESWT has a positive short-term clinical and physiological effect on the erectile function of men who respond to oral phosphodiesterase type 5 inhibitor therapy.  The feasibility and tolerability of this treatment, coupled with its potential rehabilitative characteristics, make it an attractive new therapeutic option for men with erectile dysfunction.  They stated that additional studies with long-term follow-up are needed to assess the effectiveness of this new therapy and confirm these findings.