Extracorporeal shock wave therapy for chronic calcific tendinitis of the shoulder

Shock wave therapy for rotator cuff disease with or without calcification

BACKGROUND

Shock wave therapy has seen widespread use since the 1990s to treat various musculoskeletal disorders including rotator cuff disease, but evidence of its efficacy remains equivocal.

OBJECTIVES

To determine the benefits and harms of shock wave therapy for rotator cuff disease, with or without calcification, and to establish its usefulness in the context of other available treatment options.

SEARCH METHODS

We searched Ovid MEDLINE, Ovid Embase, CENTRAL, ClinicalTrials.gov and the WHO ICTRP up to November 2019, with no restrictions on language. We reviewed the reference lists of retrieved trials to identify potentially relevant trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and controlled clinical trials (CCTs) that used quasi-randomised methods to allocate participants, investigating participants with rotator cuff disease with or without calcific deposits. We included trials of comparisons of extracorporeal or radial shock wave therapy versus any other intervention. Major outcomes were pain relief greater than 30%, mean pain score, function, patient-reported global assessment of treatment success, quality of life, number of participants experiencing adverse events and number of withdrawals due to adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion, extracted data and assessed the certainty of evidence using GRADE. The primary comparison was shock wave therapy compared to placebo.

MAIN RESULTS

Thirty-two trials (2281 participants) met our inclusion criteria. Most trials (25) included participants with rotator cuff disease and calcific deposits, five trials included participants with rotator cuff disease and no calcific deposits, and two trials included a mixed population of participants with and without calcific deposits. Twelve trials compared shock wave therapy to placebo, 11 trials compared high-dose shock wave therapy (0.2 mJ/mm² to 0.4 mJ/mm² and above) to low-dose shock wave therapy. Single trials compared shock wave therapy to ultrasound-guided glucocorticoid needling, ultrasound-guided hyaluronic acid injection, transcutaneous electric nerve stimulation (TENS), no treatment or exercise; dual session shock wave therapy to single session therapy; and different delivery methods of shock wave therapy. Our main comparison was shock wave therapy versus placebo and results are reported for the 3 month follow up. All trials were susceptible to bias; including selection (74%), performance (62%), detection (62%), and selective reporting (45%) biases. No trial measured participant-reported pain relief of 30%. However, in one trial (74 participants), at 3 months follow up, 14/34 participants reported pain relief of 50% or greater with shock wave therapy compared with 15/40 with placebo (risk ratio (RR) 1.10, 95% confidence interval (CI) 0.62 to 1.94); low-quality evidence (downgraded for bias and imprecision). Mean pain (0 to 10 scale, higher scores indicate more pain) was 3.02 points in the placebo group and 0.78 points better (0.17 better to 1.4 better; clinically important change was 1.5 points) with shock wave therapy (9 trials, 608 participants), moderate-quality evidence (downgraded for bias). Mean function (scale 0 to 100, higher scores indicate better function) was 66 points with placebo and 7.9 points better (1.6 better to 14 better, clinically important difference 10 points) with shock wave therapy (9 trials, 612 participants), moderate-quality evidence (downgraded for bias). Participant-reported success was reported by 58/150 people in shock wave therapy group compared with 35/137 people in placebo group (RR 1.59, 95% CI 0.87 to 2.91; 6 trials, 287 participants), low-quality evidence (downgraded for bias and imprecision). None of the trials measured quality of life. Withdrawal rate or adverse event rates may not differ between extracorporeal shock wave therapy and placebo, but we are uncertain due to the small number of events. There were 11/34 withdrawals in the extracorporeal shock wave therapy group compared with 13/40 withdrawals in the placebo group (RR 0.75, 95% CI 0.43 to 1.31; 7 trials, 581 participants) low-quality evidence (downgraded for bias and imprecision); and 41/156 adverse events with extracorporeal shock wave therapy compared with 10/139 adverse events in the placebo group (RR 3.61, 95% CI 2.00 to 6.52; 5 trials, 295 participants) low-quality evidence (downgraded for bias and imprecision). Subgroup analyses indicated that there were no between-group differences in pain and function outcomes in participants who did or did not have calcific deposits in the rotator cuff.

AUTHORS' CONCLUSIONS

Based upon the currently available low- to moderate-certainty evidence, there were very few clinically important benefits of shock wave therapy, and uncertainty regarding its safety. Wide clinical diversity and varying treatment protocols means that we do not know whether or not some trials tested subtherapeutic doses, possibly underestimating any potential benefits. Further trials of extracorporeal shock wave therapy for rotator cuff disease should be based upon a strong rationale and consideration of whether or not they would alter the conclusions of this review. A standard dose and treatment protocol should be decided upon before further research is conducted. Development of a core set of outcomes for trials of rotator cuff disease and other shoulder disorders would also facilitate our ability to synthesise the evidence.

Radiological and clinical predictors of long-term outcome in rotator cuff calcific tendinitis

OBJECTIVES

Knowledge on the epidemiology and long-term course of rotator cuff calcific tendinitis (RCCT) is scarce. We assessed demographics, radiological characteristics, and their association with long-term outcomes in a large patient group.

METHODS

Baseline demographics, radiological characteristics and treatment were recorded in 342 patients. Interobserver agreement of radiological measures was analyzed. Long-term outcome was evaluated with questionnaires (WORC, DASH). The association of baseline characteristics with outcome was assessed.

RESULTS

Mean age was 49.0 (SD = 10.0), and 59.5 % were female. The dominant arm was affected in 66.0 %, and 21.3 % had bilateral disease. Calcifications were on average 18.7 mm (SD = 10.1, ICC = 0.84 (p < 0.001)) and located 10.1 mm (SD = 11.8) medially to the acromion (ICC = 0.77 (p < 0.001)). Gärtner type I calcifications were found in 32.1 % (Kappa = 0.47 (p < 0.001)). After 14 years (SD = 7.1) of follow-up, median WORC was 72.5 (range, 3.0-100.0; WORC < 60 in 42 %) and median DASH 17.0 (range, 0.0-82.0). Female gender, dominant arm involvement, bilateral disease, longer duration of symptoms, and multiple calcifications were associated with inferior WORC. DASH results were similar.

CONCLUSIONS

Many subjects have persisting shoulder complaints years after diagnosis, regardless of treatment. Female gender, dominant arm involvement, bilateral disease, longer duration of symptoms, and multiple calcifications were associated with inferior outcome. Radiological measures had moderate-to-good reliability and no prognostic value.

KEY POINTS

• Most RCCT studies report on short-term outcome and/or small patients groups. • In this large, long-term observational study, RCCT appeared to not be self-limiting in many subjects. • Negative prognostic factors included female gender, more calcifications, dominant arm affected, and longer duration of symptoms. • Interobserver agreement of general radiological RCCT measures is moderate to good. • More rigorous diagnostics and treatment might be needed in specific RCCT cases.

Mechanical Stimulation (Pulsed Electromagnetic Fields "PEMF" and Extracorporeal Shock Wave Therapy "ESWT") and Tendon Regeneration: A Possible Alternative

The pathogenesis of tendon degeneration and tendinopathy is still partially unclear. However, an active role of metalloproteinases (MMP), growth factors, such as vascular endothelial growth factor (VEGF) and a crucial role of inflammatory elements and cytokines was demonstrated. Mechanical stimulation may play a role in regulation of inflammation. In vitro studies demonstrated that both pulsed electromagnetic fields (PEMF) and extracorporeal shock wave therapy (ESWT) increased the expression of pro-inflammatory cytokine such as interleukin (IL-6 and IL-10). Moreover, ESWT increases the expression of growth factors, such as transforming growth factor β(TGF-β), (VEGF), and insulin-like growth factor 1 (IGF1), as well as the synthesis of collagen I fibers. These pre-clinical results, in association with several clinical studies, suggest a potential effectiveness of ESWT for tendinopathy treatment. Recently PEMF gained popularity as adjuvant for fracture healing and bone regeneration. Similarly to ESWT, the mechanical stimulation obtained using PEMFs may play a role for treatment of tendinopathy and for tendon regeneration, increasing in vitro TGF-β production, as well as scleraxis and collagen I gene expression. In this manuscript the rational of mechanical stimulations and the clinical studies on the efficacy of extracorporeal shock wave (ESW) and PEMF will be discussed. However, no clear evidence of a clinical value of ESW and PEMF has been found in literature with regards to the treatment of tendinopathy in human, so further clinical trials are needed to confirm the promising hypotheses concerning the effectiveness of ESWT and PEMF mechanical stimulation.