Biceps tendon and superior labral injuries.

Twenty-two patients sustained injury to the biceps tendon, rotator cuff interval, or superior labrum. Seven patients with "interval lesions" underwent biceps tenodesis, one biceps repair, and three subscapularis repairs. All were satisfied, although one tenodesis failed with distal biceps retraction. Key arthroscopic findings included biceps or subscapularis fraying. Thirteen patients with "S.L.A.P. (superior labrum anterior to posterior) lesions" underwent labral debridement. All but one obtained pain relief. Eight cadaveric shoulders exhibited extreme anatomic variability of the bicipital origin/superior labral attachment. Biomechanical study showed anterior-superior and posterior-superior labral strain with simulated biceps contraction to be greatest in shoulder abduction (p < 0.01). Biceps tendon strain was greatest in shoulder adduction (p < 0.05). A continuum of injuries to the biceps tendon exist, from the rotator cuff interval to the labral attachment. Key arthroscopic findings may assist in the difficult diagnosis of interval lesions. Individual anatomy and mechanism of injury may determine the site of the lesion.