The coracoacromial ligament: the morphology and relation to rotator cuff pathology.

We dissected 80 shoulders from 44 fresh cadavers to define variants of the coracoacromial ligament and their relationship to rotator cuff degeneration. The shapes and the geometric data of the ligaments were investigated, and the rotator cuffs of the cadavers were evaluated macroscopically. Five main types of coracoacromial ligaments were found: Y-shaped, broad band, quadrangular, V-shaped, and multiple-banded. The Y-shaped ligament was the most frequent type, with a frequency of 41.3%, and the V-shaped ligament (11.2%) has not been previously reported. Of the cadavers that were dissected bilaterally, 64% showed the same type of ligament. There was no statistical significance between rotator cuff degeneration and the type or geometric measurement of the ligament. However, the coracoacromial ligaments with more than 1 bundle showed significant association with rotator cuff degeneration with a longer lateral border and larger coracoid insertion.