The acromioclavicular joint in rheumatoid arthritis.

The acromioclavicular (AC) joint was clinically and roentgenographically examined in 49 rheumatic patients with painful shoulders. Clinically, the AC joint was tender and painful in about one-third of the shoulders. Roentgenographically, AC changes were encountered in 85% of the shoulders. The AC joint destruction was frequently associated with the glenohumeral joint disease. There was a time-dependent progression of subchondral bone erosion, tapering, and osteolysis of the acromial end of the clavicle corresponding to the duration and/or severity of the rheumatoid disease.