Anterior Interosseous Nerve Palsy Associated with a Monteggia Fracture

The association between distally pointing osteophytes of the acromioclavicular joint and ruptures of the supraspinatus tendon was investigated by two different methods. In a radiologic study, 47 images of shoulders with arthrographically confirmed supraspinatus tendon ruptures were reviewed and compared with 50 images of shoulders without ruptures. Fifty-one percent of the shoulders with supraspinatus tendon ruptures had osteophytes, as compared with 14% of the normal shoulders. A series of 170 autopsy specimens of the shoulder were also examined in detail; partial supraspinatus tendon ruptures were found in 32 and full-thickness ruptures in 22 shoulders. Fifty-four percent of the shoulders with supraspinatus tendon ruptures had distally pointing acromioclavicular osteophytes, as compared with 10% of the normal shoulders. Bony spurs of the anterior acromial process were also encountered, but they were less frequent than the acromioclavicular osteophytes.