Background: Patients with subacromial impingement syndrome are often operated on when conservative treatments fail. But does surgery really lead to better results than nonoperative measures? This systematic review compared effects of conservative and surgical treatment for subacromial impingement syndrome in terms of improvement of shoulder function and reduction of pain.
Methods: A literature search for randomized controlled trials (RCTs) in PubMed, EMBASE, PEDro, and the Cochrane Central Register of Controlled Trials was conducted. Two reviewers assessed the methodological quality of the selected studies. A best-evidence synthesis was used to summarize the results.
Results: Four RCTs were included in this review. Two RCTs had a medium methodological quality, and 2 RCTS had a low methodological quality. No differences in outcome between the treatment groups were reported for any of the studies, irrespective of quality.
Conclusion: No high-quality RCTs are available so far to provide possible evidence for differences in outcome; therefore, no confident conclusion can be made. According to the best-evidence synthesis, however, there is no evidence from the available RCTs for differences in outcome in pain and shoulder function between conservatively and surgically treated patients with SIS.
Level of evidence: Review.