Biomechanical Analysis of Midfoot Instability After Bifurcate Ligament Injury and Ankle Brace Application: A Cadaveric Study.

Abstract

This cadaveric study investigated the biomechanical characteristics and stabilizing contribution of the bifurcate ligament using a multidirectional loading method and assessed the stabilizing effect of a brace after injury of the ligament. Eight freshly frozen cadaveric feet were tested for forefoot torque in inversion, eversion, adduction, and plantarflexion. Each band of the bifurcate ligament was transected sequentially, and the contribution of each portion of the ligament, as well as the stabilizing effects of the ankle brace, were examined. Stability decreased substantially after calcaneocuboid ligament transection for inversion and adduction loading. Bracing restored some stability, except for the adduction loading direction, for which it had only limited effect. The data indicate that inversion and adduction loading are strongly related to bifurcate ligament injury. The stabilizing effect of the ankle brace may have limited effectiveness for loads under adduction.