The treatment for acromioclavicular joint separations has focused on anatomic restoration of the coracoclavicular ligaments. We reviewed the detailed anatomy of trapezoid ligaments and conoid ligaments using cadavers. The subjects were 40 shoulders of the 20 cadavers. We investigated the distributed direction and attachment sites of both trapezoid and conoid ligaments. The trapezoid ligaments began at about 2 cm away from the central point of the distal coracoid process and directed toward the undersurface of the clavicle. The attachments extended from 13 to 26 mm in sagittal dimension and from 13 to 15 mm in coronal dimension. The conoid ligaments began at the medial posterior margin of the coracoid process and directed toward to the conoid tubercle in the clavicle. The attachments extended from 15 to 30 mm in sagittal dimension and from 3 to 6 mm in coronal dimension. The findings are important indices for the accurate reconstruction of the coracoclavicular ligaments in acromioclavicular joint separations.
