Development of a failure locus for a 3-dimensional anterior crutiate ligament: A finite element analysis

This study investigates the combinations of loading which cause injury to knee joint ligaments. A 3D model of a knee, including bones, cartilage, menisci and ligament bundles was created from magnetic resonance images (MRI). Material properties for bone, cartilage, meniscus and ligament were all determined based on previous published work. The model incorporates a novel approach for accounting for prestrain in ligament bundles. The ligament bundle structures were resized based to their zero load lengths and strained to their reference lengths at full extension using FEBio (University of Utah). Previous studies investigating ligament failure used 1D nonlinear spring elements for ligament structures. The 3D ligament model will provide improved accuracy for locating bundle ruptures. By monitoring stresses and strains in ligament bundles during knee joint orientation simulations, ruptures can be virtually diagnosed. The results of these simulations can be used in clinical applications. In sports where anterior cruciate ligament (ACL) injuries are prevalent, training programs can be adapted to address the avoidance of harmful knee orientations. The ability to monitor where bundle ruptures occur will provide increased insight for practitioners in identifying more precise mechanisms of injury to ligaments and cartilage within the knee joint.