Ruptures of the supraspinatus tendon. The significance of distally pointing acromioclavicular osteophytes.

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.