抄録
(Purpose)Acromioclavicular(A-C)arthrosis is diagnosed with pain of the A-C joint, the existence of an A-C painful arc and osteoarthropathy on radiograph. We examined characteristic MR images useful for the diagnosis of symptomatic A-C arthrosis.
(Materials and methods)We studied 15 shoulders in 13 cases with symptomatic A-C arthrosis. There were 11 males and 2 females,7 cases were on the right side and 8 cases on the left, and ranging in age from 24 to 63 years(mean 45 years).
Scanning was performed on a GE 1.5-T magnetic imaging system using surface coil. T1-weighted and T2-weighted sequences of all the patients were obtained in the oblique plane along the supraspinatus muscle.
(Results)In shoulder radiography, osteoarthropathy was recognized in 4, but decidedly not in the other 11.
In the MR images, we recognized hypertrophy of the distal clavicle in 8 and its atrophy in 7. Irregularities of the distal clavicle were seen in all 15 and small subchondral cysts were seen in 7. Swelling of the articular capsule was recognized in 10 and fluid stagnation in the articular capsule existed in 8 of them.
(Conclusion)Symptomatic A-C arthrosis was classified into 2 types, one the hypertrophy type and the other the atrophy type had configurations of the distal end of the clavicle in MR images. When comparing the operating findings, there were irregularities and a cyst in the distal clavicle reflecting damages of the disk, the articular cartilage and the subchondral bone. Furthermore, in symptomatic A-C arthrosis, the high incidence of swelling of the articular capsule accompanied by fluid stagnation was confirmed.
