Failure locus of the anterior cruciate ligament: 3D finite element analysis

Abstract

Anterior cruciate ligament (ACL) disruption is a common injury that is detrimental to an athlete's quality of life. Determining the mechanisms that cause ACL injury is important in order to develop proper interventions. A failure locus defined as various combinations of loadings and movements, internal/external rotation of femur and valgus and varus moments at a 25(o) knee flexion angle leading to ACL failure was obtained. The results indicated that varus and valgus movements were more dominant to the ACL injury than femoral rotation. Also, Von Mises stress in the lateral tibial cartilage during the valgus ACL injury mechanism was 83% greater than that of the medial cartilage during the varus mechanism of ACL injury. The results of this study could be used to develop training programmes focused on the avoidance of the described combination of movements which may lead to ACL injury.

The effects of knee joint kinematics on anterior cruciate ligament injury and articular cartilage damage

“…Research has validated the transepicondylar axis as an optimal axis for representing proper knee flexion (Churchill et al 1998). Also, the transepicondylar axis was used in several previous investigations, and the results were in good agreement with experimental data (Yang et al 2010a;Homyk et al 2012). For these reasons, in this investigation the knee flexion axis of rotation was chosen to be the transepicondylar axis.…”

“…Bone was modeled as rigid, as it is much stiffer than the soft tissue it interacts with (Fung and Zhang 2003;Haut Donahue et al 2003;Yang et al 2010a;Homyk et al 2012). The articular cartilage was modeled as isotropic linear elastic and the meniscus was modeled as transversely isotropic linear elastic, with the material properties shown in Table 1.…”

“…At each horn attachment 10 linear springs were used to attach the meniscal horn to the tibial plateau. A transverse ligament was modeled as a single spring element, which attached the anterior horns of the menisci to each other (Haut Donahue et al 2003;Yang et al 2010a;Homyk et al 2012). There were six contact interactions between the femoral articular cartilage, the tibial articular cartilage and the medial and lateral menisci.…”

“…A subject-specific 3D FE model of a left knee was created from sagittal view magnetic resonance images (MRI) of a healthy 26-year-old male with a frontal plane alignment angle of 7.678 valgus, seen in Figure 1 using the method provided by Homyk et al (2012) and Yang et al (2010a), similar to Haut Donahue et al (2003). 1 Images were obtained using short bore, high-field 1.5 Tesla MRI and a fat suppressed fast spin echo sequence with a TE ¼ 10 ms, 160 £ 160 mm field of view, and slice thickness of 2 mm with 256 £ 256 matrix.…”

“…Ligament insertion sites were determined from the MRI, similar to the group's previous work (Yang et al 2010a;Homyk et al 2012). The nonlinear spring force-displacement relationship used is defined as a piecewise continuous function,…”