Rate of symptomatic subscapularis failure in anatomic total shoulder arthroplasty in patients greater than 70 years of age

Background: One reason for success after anatomic total shoulder arthroplasty (TSA) survival rate is a well-functioning rotator cuff. Concerns regarding risk of subscapularis (SC) failure in older patients may shift surgeons toward performing reverse arthroplasty. This study aimed to report the rate of clinically relevant SC failure after TSA in elderly patients. Methods: We retrospectively reviewed 282 patients greater than 70 years who underwent TSA for osteoarthritis with a minimum of 6-month follow-up (mean 1.8 years). Clinically relevant SC failure was defined as either: (1) American Shoulder and Elbow Score (ASES) below a threshold score with a positive abdominal compression or anterior subluxation or (2) reoperation for SC deficiency. Results: Of 282 patients, 23 patients demonstrated possible SC failure. Five patients had confirmed SC failure, but only four patients (1.4%) were clinically symptomatic. Three patients (1.06%) underwent revision surgery for SC deficiency. Symptomatic SC failure patients had higher body mass index, higher comorbidity burden, lower ASES scores, and higher pain scores prior to revision surgery (mean 1.5 years). Anterior subluxation on radiographs was prevalent in 100% of the failure group. Discussion: Clinically symptomatic SC failure after TSA is rare (1.4%). Older age should not represent a contraindication to TSA due to the perceived risk of SC failure.