Background: Isolated tears of the subscapularis occur less commonly than those involving the superior and posterior components of the rotator cuff. The purpose of the present study was to evaluate the structural integrity and clinical outcomes after arthroscopic repair of isolated subscapularis tears.
Methods: A prospective study of seventeen consecutive patients who were managed with an all-arthroscopic repair of the subscapularis tendon was performed. The study group included thirteen men and four women who had an average age of forty-seven years at the time of surgery. The average interval from the onset of symptoms to the time of surgery was twenty-four months. Thirteen tears were traumatic, and four were degenerative. Seven patients had a tear involving the superior third of the tendon, six had a tear involving the superior two-thirds of the tendon, and four had complete separation of the subscapularis from its insertion on the lesser tuberosity. Clinical findings were assessed for all patients preoperatively and postoperatively with use of the Constant and University of California at Los Angeles scoring systems, and all patients had postoperative computed tomographic arthrography studies to evaluate the structural integrity of the repair.
Results: The average duration of follow-up was twenty-nine months. When the preoperative findings were compared with the most recent findings, the average relative Constant score had improved from 58% to 96% (p < 0.05), the average University of California at Los Angeles score had improved from 16 to 32 points (p < 0.05), the average pain score had improved from 5.9 to 13.5 points (p < 0.05), the average forward flexion had improved from 146 degrees to 175 degrees (p < 0.05), the average external rotation had improved from 50 degrees to 60.3 degrees (p < 0.05), the average internal rotation had improved from the level of the sacrum to L1-L2 (p < 0.05), and the average abduction strength had improved from 7.4 to 15.6 points (p < 0.05). The structural integrity of the repair was completely intact in fifteen patients and was partially reruptured in two patients on the basis of computed tomographic arthrography. Progression of fatty infiltration of the subscapularis was not observed in any patient. Subjectively, twelve patients were very satisfied with the result, four were satisfied, and one was not satisfied.
Conclusions: Arthroscopic repair of an isolated subscapularis tear can yield marked improvements in shoulder function, can significantly reduce pain, and can result in a durable structural repair.
Level of evidence: Therapeutic Level IV.