Background This systematic review explored the midterm effectiveness of extracorporeal shockwave therapy (ESWT) in reducing pain and improving shoulder function. Calcified rotator cuff tendinitis is a common cause of chronic shoulder pain that leads to significant pain and functional limitations. ESWT is an alternative to surgery when conservative treatments such as nonsteroidal antiinflammatory drugs, steroidal injections, and physiotherapy fail to relieve symptoms. It is hypothesised that ESWT is effective in the midterm for reducing pain and improving function for patients with chronic calcific tendinitis and that a dose-response relationship exists in the treatment parameters for effectiveness. Materials and methods Articles were electronically searched from the Cochrane Controlled Trials Register, MEDLINE, CINAHL, PUBMED, EMBASE, SPORTSDiscus and PEDro using a comprehensive search strategy. Studies were included if they were randomized controlled trials testing the midterm effectiveness of ESWT for chronic calcific tendonitis. Methodologic quality was assessed by PEDro (total score = 10). The strength of the evidence was reported using the National Health and Medical Research Council body of evidence framework. Results Six of the nine included studies scored 7 or more for methodologic quality. All studies had follow-up periods of at least 6 months. Common methodologic flaws were insufficient blinding of clinicians and assessors. There was consistent evidence of midterm effectiveness of ESWT in reducing pain and improving shoulder function for patients with chronic calcified tendinitis. Discussion ESWT is a potential alternative to surgery with good mid-term effectiveness and minimal side effects. This review noted several limitations with the current body of evidence. Studies were mainly from a few European countries involving medical doctors, with a lack of diverse perspectives and effectiveness evaluation from other health professionals who might use this treatment option for patients with chronic calcific tendinitis. Further, the different outcome measures used and inadequate reporting details in the included studies did not permit a quantitative synthesis of the effectiveness of this treatment. A lack of follow up period beyond one year in the studies also precluded conclusion to be made on the longer term effectiveness of ESWT. Conclusion Due to variable treatment parameters (eg dosage), this review was unable to provide clear guidance of the dose-effect of the midterm effectiveness of ESWT. Studies of better methodologic design using standardized treatment protocols and studies with longer follow-up are required.
