The effect of subscapularis repair on dislocation rates in reverse shoulder arthroplasty: a meta-analysis and systematic review.

Background: Reverse total shoulder arthroplasty is an effective treatment for patients with rotator cuff arthropathy; however, complication rates are relatively high (19%-50%), with implant instability and infection being particularly devastating to overall outcomes. The objective of this study was to analyze the highest level of data comparing dislocation rates and outcomes in reverse total shoulder arthroplasty with and without the subscapularis tendon repaired.

Methods: The databases MEDLINE, Embase, and CINAHL were searched using a sensitive search strategy for this meta-analysis/systematic review. Eligibility included any studies in which patients were treated with a reverse total shoulder arthroplasty in which the status of the subscapularis tendon could be determined. A data extraction form was developed to collect select data from the included studies. A meta-analysis was performed on pooled data of 5 studies comparing dislocation rates and 3 studies comparing postoperative forward elevation, rate of infection, overall complication rates, and fractures.

Results: Two independent researchers reviewed 1008 studies. Seven studies met inclusion criteria. A meta-analysis was performed on all level III studies, resulting in 1306 patients being analyzed. Results demonstrated lower dislocation rates in the subscapularis repair group (odds ratio, 0.19; P < .001). However, in patients without a subscapularis repair, lateralized center of rotation (COR) resulted in a significantly lower dislocation rate compared with medialized COR (odds ratio, 0.24; P < .001).

Conclusion: The results of our meta-analysis of the available data demonstrated a decrease in dislocation risk when the subscapularis tendon was repaired in medialized and lateralized designs. When subscapularis repair is not performed, lateralized COR, regardless of humeral socket design, may reduce the dislocation rates.