Ligamentous anatomy of the distal clavicle.

We describe the insertional variations of supporting ligaments of the acromioclavicular joint, especially with respect to gender. We analyzed 41 cadaveric clavicles (22 female and 19 male) with attached ligaments. The distance between the insertion of the trapezoid ligament and the distal end of the clavicle was not significantly different between sexes, although that of the conoid ligament and the mean anteroposterior width of the distal clavicle was significantly greater in men. Although there are significant sex-related differences in the insertional distances of the CC ligaments, resection of less than 11.0 mm should not violate the trapezoid ligament and less than 24.0 mm should not violate the conoid ligament in either sex in 98% of the general population. Resection of more than 7.6 mm of the distal clavicle in men and 5.2 mm in women, performed by an arthroscopic approach, may violate the superior acromioclavicular ligament.