Morphological features of the cervical ligament.

The purpose of this study was to clarify the morphological characteristics of the cervical ligament (CL). This study examined 80 legs from 40 Japanese cadavers. The CL was classified by the number of fiber bundles. The morphological features measured were fiber bundle length, width, thickness, and angle with the sagittal plane. The CL was classified as follows: Type I, the CL is a single fiber; Type II, the CL consists of a superficial fiber and an inferior fiber; and Type III, the CL consists of a superficial fiber, intermediate fiber, and inferior fiber. Type I was seen in 15 feet, Type II in 57 feet, and Type III in 8 feet. In comparisons of morphological features within each type, significant differences were seen in fiber bundle length, width, and angle between superior fiber bundles and inferior fiber bundles of Type II and Type III. In comparison among types, the total fiber bundle width was significantly wider in Type II and Type III than in Type I, and the angle was significantly smaller in Type III than in Type I. The results of this study suggested that each type may have different sub-talar joint control functions.