Abstract
Purpose: Although rotator cuff tears are well documented in the literature, there have been relatively few reported cases of isolated subscapularis injuries without lesions of the long head of the biceps brachii. We highlight key points for the diagnosis and successful arthroscopic treatment.
Case: A healthy 32-year-old man sustained injury to his right shoulder when he tried to stop his leashed dog from chasing another animal. In his attempt to restrain the dog, his right shoulder was forced into extension and external rotation. He immediately experienced shoulder pain, which was later diagnosed as a contusion of the shoulder, and which was treated conservatively by his doctor. When we examined him 10 months after the injury, he had point tenderness of the anterior shoulder. There was limited movement to 150° of active forward flexion and 145° abduction associated with pain. The impingement sign of Hawkins and the belly press and lift-off tests were positive. There was no shoulder instability. Magnetic resonance imaging showed a partial-thickness articular-side tear of the subscapularis tendon. An arthroscopic view from the posterior portal showed that the middle portion of the articular-side of the subscapularis tendon (length 10 mm, depth < 5 mm) was detached from its humeral insertion site. Debridement of the partially torn tendon was then undertaken. No other rotator cuff abnormalities or lesions of the long head of the biceps brachii and its pulleys were detected intraoperatively. Three months postoperatively the patient had recovered full active range of motion. The impingement sign of Hawkins and the belly press and lift-off tests were negative and his Japanese Orthopaedic Association shoulder score improved from 66 to 100 points.
