Abstract
Acromioclavicule joint separation was an usual injury in everyday practice. The selection of the surgical procedure on these patients was made from the severity of the separation or the damage of coracoclavicle ligaments. However, evaluation on the radiographic findings was not estimated as the trapezoid ligament and conoid ligament individual, but in the damage of the whole coracoclavicle ligaments. Furthermore, type 2 in Tossy's or Rockwood's criteria did not indicate the severity of damage in the coracoclavicular ligament definitely. On the other hand, anatomy and the function of the trapezoid ligament and conoid ligament were not studied enough. We reviewed the detailed anatomy of trapezoid ligament and conoid ligament in using cadaver. The subjects were 20 cadavers 40 shoulders (eight males, 12 females), and their ages ranged from 62 to 82 years old (mean: 71.3 years old). As an anatomical study in the coracoclavicular ligament, we reviewed the running direction and attachment site of both trapezoid and conoid ligament. The trapezoid ligament began at the front 2/3 in the base of the coracoid process and directed toward the inferior surface of the clavicle. The attachment site extended from 13 mm to 26 mm in length (mean: 18.7 mm) and from 13 mm to 15 mm in width (mean: 14.3 mm). On the other hand, the conoid ligament began at the rear 1/3 in the base of the coracoid process and directed toward to the conoid tubercle in the clavicle. The attachment site extended from 15 mm to 30 mm in length (mean: 21 mm) and from 3 mm to 6 mm in width (mean: 4.7 mm) to 35∼55 (mean: 45.4) mm on the posterior margin of the clavicle. From this study, it is indicated the potency which the differentiation in the severity of damage existed between the trapezoid and conoid ligament on the acromioclavicle joint separation.
