Ultrasound evaluation and clinical correlation of subscapularis repair after total shoulder arthroplasty

Abstract

The purpose of this study was to document the subscapularis healing rate by use of postoperative ultrasound and correlate healing to physical examination findings. We included 23 patients (30 shoulders), who underwent total shoulder arthroplasty in the study. The evaluation included a standard history and physical examination, ultrasound evaluation, and outcome questionnaires. The postoperative examination included careful documentation of an abdominal-compression test to evaluate subscapularis function. All patients had an improvement in functional outcome scores and shoulder range of motion. Of 30 shoulders, 26 (87%) had an intact subscapularis as determined by ultrasound. By use of ultrasound as the gold standard, the abdominal-compression test had 7 false-positive results, 3 false-negative results, 19 true-negative results, and 1 true-positive result. The sensitivity of the abdominal-compression test was 25%, and the specificity was 73%. The negative predictive value was 86%, and the positive predictive value was 13%. The abdominal-compression test demonstrated a low sensitivity, specificity, and positive predictive value in this study for the assessment of subscapularis function after total shoulder arthroplasty. If a subscapularis tear is suspected in a patient after total shoulder arthroplasty, the abdominal-compression test is unreliable in predicting a subscapularis defect.