Subscapularis repair for reverse shoulder arthroplasty: a systematic review and meta-analysis

Background: The purpose of this study is to perform a systematic review of the literature evaluating the importance of subscapularis repair in patients who underwent reverse shoulder arthroplasty (RSA).Methods: A systematic search of articles in PubMed, EMBASE, and the Cochrane Library databases was carried out according to the PRISMA guidelines. Cohort studies comparing RSA with subscapularis repair vs. RSA without subscapularis repair were included. All statistical analysis was performed using Review Manager. A P value of <.05 was considered to be statistically significant.Results: Seventeen studies with 2620 patients were included. Subscapularis repair resulted in less instability compared to without subscapularis repair (0.8% vs. 4.2%, P = .04), and there were no significant differences in rate of instability with lateralization (0.6% vs. 1.6%, P = .40), revision rates (2.6% vs. 3.9%, P = .62), and complication rates (7.7% vs. 4.9%, P = .21). Subscapularis repair had improved American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) scores (83.6 vs. 80.2, P = .02) and Constant scores (72.6 vs. 68.9, P < .01) but there was not a significant difference in visual analog scale pain scores (1.2 vs. 1.6, P = .11). Subscapularis repair had a significant difference in forward flexion (140 degrees vs. 137 degrees, P = .04) and internal rotation score (5.5 vs. 4.6, P = .001); however, there was no significant difference in external rotation (35 degrees vs. 35 degrees, P = .80) and abduction (117 degrees vs. 123 degrees, P = .13). Conclusion: This study found that RSA with subscapularis repair demonstrated a reduction in the occurrence of implant instability with medialized implants. However, subscapularis repair did not yield improvements in revision rates, complications, or instability with lateralized implants. Additionally, other outcome measures such as ASES, Constant score, and range of motion exhibited statistically significant improvements with subscapularis repair but did not surpass clinically significant thresholds.Level of evidence: Level IV; Systematic Review (c) 2023 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights reserved.