Tears of the supraspinatus tendon associated with "hidden" lesions of the rotator interval.

Exploration of the rotator interval during repair of 116 apparently "isolated" supraspinatus tendon lesions have revealed "hidden lesions" of the coracohumeral ligament, the superior glenohumeral ligament, and the superior portion of the subscapularis tendon in 19 cases. Epidemiologic characteristics were comparable with other series with the exception of involvement of the dominant shoulder in 95%. Arthroscopic computed tomography documented the lesion in 85% of the cases. At surgery the superficial layer of the coracohumeral ligament was always intact. After splitting of the rotator interval the lesion was visible and consisted of a local disinsertion of the common insertion of the superior glenohumeral ligament and the coracohumeral ligament and the deep superior fibers of the subscapularis tendon. It measured 1 to 2 cm in the superior-inferior direction. The biceps tendon was ruptured in 2 cases, subluxated in 14, and in its normal position in 5. The treatment consisted of intraosseous reinsertion of the supraspinatus tendon, recentering of the biceps, and reinsertion of the torn structures to reconstruct a functional pulley system. The patients have been reviewed with a mean follow-up of 20 months (range 12 to 36 months). A secondary rupture of the long head of the biceps has been observed in 25% of the cases after recentering of the tendon.