Finite Element Modelling of Knee Joint and Femur for Future Injury Assessment

Abstract

The purpose of this thesis was to develop and validate a FE model of the femur and knee with associated ligaments, tendons and cartilage. In the future, the model will be integrated into the SAFER HBM representing a 50th percentile male and used to develop the capability of the SAFER HBM to assess femur and knee injury risk. In total, eleven parts, including the femur, patella, anterior cruciate ligament, poste rior cruciate ligament, medial collateral ligament, lateral collateral ligament, patellar tendon, quadriceps tendon and cartilage on the distal end of the femur, posterior side of the patella and on the tibial plateau, were modelled using eight node solid el ements. The femur and the patella models are based on geometry models from a CT scan of a 50th percentile female, and the soft tissue models are based on geometry descriptions found in the literature. The cortical and trabecular bone tissues of the femur and the patella were modelled with isotropic material properties. All models were meshed in accordance to the requirements and quality criteria of SAFER HBM standards. The femur was validated against previously published three-point-bending and com bined loading tests. 23 tests were replicated using explicit LS-DYNA simulations. Two methods were used to evaluate the correlation between the tests and the simula tions. The response of the simulations, reaction force of the actuator versus actuator displacement, were plotted together with statistically evaluated corridors, ±2 stan dard deviations of the mean reaction, from the tests. To assess the correlation in an objective sense, a CORA evaluation was made on the time-history results. The results showed that the average time-force CORA score were 0.720 and 0.752 for the three-point-bending set and the combined load set. This CORA score corresponds to good biofidelity.