抄録
The acromioclavicular joint separation was divided into 3 types by Tossy or 6 types by Rockwood. However, the trapezoid and conoid ligament, which were composed of the coracoclavicular ligament, were not estimated in detail in those classifications. In this study, we investigated the sites and degrees of ligament injury in types 1, 2, 3, and 5 acromioclavicular joint separations by magnetic resonance images. There were 13 patients (10 males, 3 females), and their ages ranged from 20 to 58 years old (mean: 35.5 years old). According to Rockwood's criteria, these patients consisted of 1 case in type 1, 5 cases in type 2, 4 cases in type 3, and 3 cases in type 5. MR and enhanced MR images were performed in all cases within 3 days after injury, and evaluated coracoclavicular ligament. Both the trapezoid and conoid ligament were torn in 6 cases out of 7 cases of type 3 and 5. Both ligaments were ruptured at the same site in 4 of 6 cases. However, there were 2 cases that both ligaments ruptured at a different site. On the other hand, the conoid ligament did not recognize clear abnormal findings, but trapezoid ligament was torn in all cases of type 2. From these results, we thought that detailed evaluation of acromioclavicular joint separation could not be made by a used classification.
