Background: Diagnosis, operative treatment, and outcome assessment of isolated traumatic subscapularis tendon tears have not been widely studied.
Purpose: To report the clinical outcome, value of clinical tests, predictive outcome factors, and return to sports in the management of isolated traumatic subscapularis tendon tears.
Study design: Case series; level of evidence, 4.
Methods: Thirty consecutive patients with a confirmed isolated subscapularis tear, except for associated biceps tendon injury or humeral avulsion of the glenohumeral ligaments (HAGL) lesions, found at arthroscopy were included in the study. The average age of the study population was 43.1 years. In all 30 patients, a traumatic event caused the onset of symptoms. The mean delay between trauma and surgery was 4 months. All patients underwent open tendon reconstruction with a suture anchor technique via a deltopectoral approach. Clinical assessment was done using the Constant score and specific subscapularis tests. Postoperative tendon integrity was assessed with ultrasound and magnetic resonance imaging. Sports activity, including competition level, sports discipline, and postoperative return to sports, was evaluated.
Results: The average duration of follow-up was 46 months (range, 25-72 months). Seven patients had a full-thickness tear of the upper third of the tendon, 11 patients a full-thickness tear of the upper two-thirds of the tendon, and 12 patients had a complete subscapularis tendon tear. The Constant score increased from 51.3 preoperatively to 82.2 postoperatively (P < .01). Twenty-seven patients rated their postoperative result as excellent or good. Most positive preoperative lift-off and belly-press tests were reversed by surgery, with a rate of 6 (20%) persistent positive tests after surgery. Positive postoperative subscapularis tests were more likely related to a higher preoperative degree of fatty subscapularis muscle infiltration (P < .05). Ultrasound and magnetic resonance imaging revealed a structural intact repair at follow-up in 28 shoulders (93%). Seventy-five percent of athletes returned to their previous competition level.
Conclusion: Early repair of isolated traumatic subscapularis tendon tears and associated biceps tendon lesions or HAGL lesions achieves good functional outcomes with a low re-rupture rate and allows return to sports activity. Delay of surgery and higher degrees of preoperative fatty infiltration of the subscapularis muscle impair postoperative subscapularis function.