The effectiveness of extracorporeal shock wave therapy on adhesive capsulitis of the shoulder: a systematic review and meta-analysis

INTRODUCTION: Adhesive capsulitis is a common shoulder disorder presenting with pain and limitation of passive and active shoulder range of motion and characterized by a chronic inflammation that causes capsular thickening. Extracorporeal shock wave therapy (ESWT) is a non-surgical treatment of different musculoskeletal disorders. Since intervention modalities and treatment protocols used in adhesive capsulitis are different, a systematic review and meta-analysis is necessary to verify the effectiveness of ESWT and to evaluate the number and quality of existing studies and the eventual need for further randomized controlled trials (RCTs). EVIDENCE ACQUISITION: Data were obtained from PubMed, Scopus, Cochrane Library, Google Scholar, and PEDro, considering articles published until June 2018. EVIDENCE SYNTHESIS: Seven studies met the inclusion criteria. ESWT, if compared to placebo treatment, had a significant effect on pain immediately after treatment, at short term and at mid/long term (Effect size [ES]=-1.62 [95% CI: -3.08 to -0.16], ES=-1.31 [95% CI: -2.15 to -0.46] and ES=-2.98 [95% CI: -4.57 to - 1.38] respectively). ESWT compared to other treatment was significantly more effective immediately after treatment both on pain and on shoulder range of motion (ES=-2.06; [95% CI: -3.30 to -0.81] and ES=1.72 [95% CI: 0.36 to 3.08] respectively). CONCLUSIONS: The results of this review support the use of ESWT in adhesive capsulitis especially when combined with physical therapy and home-based exercises programs. However, further high quality RCTs are necessary to define properly ESWT effects and its eventual superiority over other conservative therapies.