抄録
The acromioclavicle joint separation was divided into three types by Tossy. Generally type 2 presented subluxation of acromioclavicle joint and did not indicate the damage of coracoclavicule ligaments. On the other hand, type 3 presented dislocation of that joint and suggested rupture of the coracoclavicle ligaments. However, the trapezoid and conoid ligaments, which were composed of the coracoclavicle ligaments, were not estimated in detail on that classification. We thought that the damage of trapezoid or conoid ligament participated in the severity of joint subluxation on type 2. On the patients with type 2 or 3, we performed the enhanced MR images and studied the damage of both ligaments. There were 8 patients (6 males, 2 females), and their ages ranged from 24 to 58 years old (mean: 37 years old). According to Tossy's criteria, these patients consisted of 1 case in type 1, 3 cases in type 2 and 4 cases in type 3. We performed the enhanced MR images in all cases within 3 days after injury, and evaluated coracoclavicle ligaments consisting of the trapezoid and conoid ligaments. Both trapezoid and conoid ligaments ruptured in all cases of type 3. On the other hand, the conoid ligament did not recognize clear abnormal findings, but trapezoid ligament ruptured in all cases of type 2. We recognized the rupture of the trapezoid ligament in all cases of type 2. From the results, we thought that detailed evaluation of acromioclavicular joint separation could not be made by a used classification.
