Detection of acromioclavicular joint pathology in asymptomatic shoulders with magnetic resonance imaging

The purpose of this study was to determine the prevalence of acromioclavicu lar joint (ACJ) arthritis with magnetic resonance imaging (MRI) evaluation in asymptomatic patients. Fifty shoulders in 42 patients were evaluated wit h the use of standard MRI techniques. There were 18 men and 24 women with a n average age of 35 years (range, 19 to 72). ACJ arthritic changes were gra ded on a scale from to 4 (none, mild, moderate, and severe), based on the a mount of subacromial fat effacement, joint space narrowing, irregularity, c apsular distension, and osteophyte formation. Forty-one (82%) of 50 shoulde rs had abnormalities consistent with arthritis on MRI. Patients were divide d into two groups according to age: chose older than 30 years and those 30 years old or younger. In the 30-and-under age group, 68% of the shoulders h ad arthritic changes, whereas in the over-30 age group, 93% had arthritic c hanges. Furthermore, in a comparison of the two groups, more advanced arthr itic changes were found in the over-30 age group (P < .05). Clinical decisi ons to resect the ACJ should correlate the physical examination with the MR I findings because many patients may be clinically asymptomatic.