Subscapularis Repair in Reverse Total Shoulder Arthroplasty: Differences in Outcomes Based on Preoperative Quality of Subscapularis Tendon.

Abstract

This study examines the influence of preoperative fatty infiltration (FI) of the subscapularis tendon (SBS) on outcomes following reverse total shoulder arthroplasty (rTSA) with SBS repair. A cohort of 161 rTSA patients with SBS repair, followed for a mean of 45.3 months, was divided into three groups based on FI: Group A (intact upper and lower portions, <i>n</i> = 85), Group B (intact lower portions, <i>n</i> = 44), and Group C (fatty infiltrated in both portions, <i>n</i> = 32). The mean age was 74.5 years (range: 65-95). Preoperative FI displayed significant disparity among the groups: Group A (1.18 ± 0.60), Group B (2.95 ± 0.56), and Group C (4.0 ± 0.00) (<i>p</i> < .001). Group A exhibited a more positive trend in activities of daily living, particularly in toileting ability (81% in Group A, 68% in Group B, and 72% in Group C), although without statistical significance (<i>p</i> = 0.220). Complication rates varied: Group A had seven acromial fractures (8%), three cases of instability (3%), and six instances of scapular notching (7%). Group B experienced four acromial fractures (9%) and four cases of scapular notching (9%), while Group C had only one case of scapular notching (3%) (<i>p</i> = 0.733). In cases characterized by favorable preoperative SBS quality, there was an elevation in functional internal rotation (IR) post-surgery, accompanied by an increased incidence of postoperative complications. Hence, careful consideration is advised when determining the necessity for SBS repair. Level III, retrospective comparative study.