Pathogenesis of the Subscapularis Tendon Tear

Abstract

Twelve cases with isolated tear of the subscapularis tendon were observed during 250reconstructive procedures on the rotator cuff. The patients' age was 51.6 years on average. All of the patients had a definite history of trauma to an affected shoulder and persistent pain in the anterior shoulder part, combined with the inability to evevate the extremity. Arthrography was performed on all, and revealed that the dye had extravasated into the subacromial bursa, however, the supraspinatus tendon was intact on the external rotation view. Operative findings revealed that an isolated rupture of the subscapularis tendon was confirmed in all. In 10 cases with rupture of the supero-medial part of the subscapularis tendon, medial dislocation of the bicipital long tendon was observed. Therefore, the authors conclude that the supero-medial part of the subscapularis tendon, including the medial bundle of the coracohumeral ligament, is the most important portion which keeps the bicipital long tendon aligned with the sulcus, and that during reconstructive procedures on the shoulder capsule, these changes should be carefully looked for and evaluated.