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

Abstract

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. 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. 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). The combination of subscapularis repair and glenosphere implant lateralization in RSA translates to significantly less clinical improvement. Patients who underwent both subscapularis repair and glenosphere lateralization had significantly less improvement in ASES scores. Level III.