Subluxations and dislocations of the tendon of the long head of the biceps.

Seventy-one cases of subluxation or dislocation of the long head of the biceps tendon (LHB) were retrospectively evaluated. Subluxation was observed in 25 (35%) cases combined with partial tearing of the subscapularis tendon and in 70% with tears of the supraspinatus tendon. Dislocation was defined as a permanent loss of contact between the tendon and the intertubercular groove; it was observed in 46 (65%) cases. Dislocation was associated with complete rupture of the subscapularis tendon in 23 cases, with partial tearing in 21 cases, and with an intact subscapularis tendon in 2 cases. Out of a series of 445 rotator cuff repairs, medial displacement of the LHB was found in 16%. In 70% of all cases dislocation of the long biceps tendon was associated with massive rotator cuff tears including the supraspinatus and infraspinatus tendons. Although "pseudoparalysis" of the shoulder (sudden loss of active elevation) was observed in 46% of all cases, no specific clinical test correlated to the presence of medial displacement of the LHB. Arthrography revealed displacement of the LHB in 28%, whereas arthro-computed tomography demonstrated lesions in 76%. The authors believe that medial displacement of the LHB can easily be overlooked during open surgery, and opening of the rotator interval is an essential part of rotator cuff repair.