Subscapularis tendon tears.
Pathology of the subscapularis tendon is both infrequently identified and not commonly considered as a major source of shoulder pain and dysfunction. Subscapularis tendon pathology can present as isolated tears; partial-thickness tears; anterosuperior tears, also involving the supraspinatus tendon; complete rotator cuff avulsion; and rotator interval lesions, in which instability of the long head of the biceps tendon may dominate the clinical presentation. Although an accurate physical examination is paramount, modalities such as arthroscopy, magnetic resonance imaging, and ultrasound have advanced knowledge of the spectrum of abnormalities involving the subscapularis tendon. Nonsurgical management may be effective for most partial tears. Surgically, open repair is more frequent than use of arthroscopic techniques. Tears of the subscapularis tendon portend a different prognosis than do supraspinatus tendon tears, especially when the injury is acute and diagnosis is delayed.