Clinical Outcomes After Reverse Shoulder Arthroplasty With and Without Subscapularis Repair: The Importance of Considering Glenosphere Lateralization

Introduction: Recent biomechanical data suggests that repairing the subscapularis during reverse shoulder arthroplasty (RSA) can increase the force required by the posterior rotator cuff and deltoid to elevate the arm. Methods: We retrospectively studied patients who underwent primary RSA and had baseline and minimum 2-year postoperative American Shoulder and Elbow Surgeons (ASES) shoulder scores, stratified them according to subscapularis management, then subgrouped them according to lateralization of the glenosphere component. Results: Patients with subscapularis repair and a lateralized glenosphere had significantly less improvement in ASES scores than did those without lateralization (P = 0.016) and patients without subscapularis repair (P = 0.006). Individually, subscapularis management (P = 0.163) and glenosphere lateralization (P = 0.847) had no significant effect on the change in ASES score but in combination did have a significant effect on the change in ASES score (P = 0.002). Discussion: The combination of subscapularis repair and glenosphere implant lateralization in RSA translates to significantly less clinical improvement. Conclusions: Patients who underwent both subscapularis repair and glenosphere lateralization had significantly less improvement in ASES scores. Level of Evidence: Level III.