Isolated rupture of the subscapularis tendon.
Sixteen consecutive patients were managed operatively for repair of an isolated traumatic rupture of the subscapularis tendon in the absence of avulsion of the lesser tuberosity. All of the patients were men. The diagnosis was made for each patient on the basis of the clinical examination and was confirmed by imaging studies and operative exploration. The operative treatment consisted of mobilization of the subscapularis after exploration and protection of the axillary nerve, transosseous reinsertion of the tendon to a trough created at the lesser tuberosity, closure of the rotator interval, and protection of the shoulder for six weeks postoperatively. The average duration of follow-up was forty-three months (range, twenty-four to eighty-four months). Thirteen patients subjectively rated the result as excellent or good. The average functional score of the shoulder, as assessed according to the system of Constant, was 82 per cent of the average age and gender-matched normal value. Active flexion was normal in twelve patients, was decreased by 15 degrees or less in three, and was severely limited in one patient. The capacity of the patients to work in their original occupations had increased from an average of 59 per cent of full capacity preoperatively to an average of 95 per cent postoperatively (p = 0.006). Operative treatment proved to be economically sound within the Swiss National Accident Insurance system. The quality of the result did not depend on the capacity for work at the time of the operation, on the type of work in which the patient was engaged, on the state of the biceps, or on the duration of follow-up. Conversely, the results were less successful when there was an increased delay from the time of the injury to the time of the operative repair.