Four RCTs (373 patients; range 80 to 114) were included in the review. Trial quality was reported to be variable. All four trials reported adequate generation and concealment of allocation. Only two trials reported appropriate experience or skills of care providers. Clinical outcome assessors were blinded in one trial. Patients were blinded in two trials. Mean follow-up ranged from 12 to 24 months. Follow-up rate ranged from 33.3% to 100%.
There were no significant differences in Western Ontario Rotator Cuff index (WORC) scores between patients treated with subacromial decompression and those not treated at follow-up (one trial; details not reported). The same trial also found no differences in WORC scores for acromion type.
There were no significant differences between groups at one year follow-up for age- and gender-normalised total Constant scores (two trials) and ASES (American Shoulder and Elbow Surgeon) scores (three trials), postoperative range of motion (one trial), or for rates of reoperation (two trials).
Subgroup and sensitivity analyses reported similar results.
There was no evidence of significant statistical heterogeneity for any of the analyses.