Subscapularis Function After Total Shoulder Arthroplasty Using Lesser Tuberosity Osteotomy or Tenotomy

Subscapularis dysfunction is a recognized complication after total shoulder arthroplasty (TSA). However, optimal subscapularis management during TSA is controversial. Subscapularis tenotomy (ST) has been used, whereas lesser tuberosity osteotomy (LTO) has gained popularity. This study compares the clinical outcomes in patients undergoing TSA with either ST or LTO, focusing on subscapularis strength and overall function.

Records were reviewed for TSA performed from 2010 to 2016 by a single surgeon at one institution. Patient age, sex, hand dominance, and the time of follow-up were recorded. Radiographs were obtained and interpreted. Range of motion was measured and the American Shoulder and Elbow Surgeons scores obtained. A graded belly-press test was used to determine the overall subscapularis function. Subscapularis strength was measured during a resisted belly-press maneuver. Statistical analysis was performed using a paired Student t-test or Fisher exact test, with P < 0.05 determining statistical significance.

Overall, 28 shoulders constituted the LTO group with 37 in the ST group. No difference was found regarding age, whether their surgical site was their dominant extremity, or the time to follow-up. Radiographically, all osteotomies went on to union, with one malunion noted. Range of motion was equivalent. No statistical difference was noted in subscapularis strength or in the American Shoulder and Elbow Surgeons scores. The overall subscapularis function also failed to show any notable difference.

In conclusion, either LTO or ST can be used during TSA to achieve successful clinical outcomes. The method of subscapularis management did not affect the subscapularis strength or overall function.