Investigation of Impact Response and Fracture of the Human Femur by Finite Element Modeling

The mechanical response of a plane strain finite element model depicting an axial midsection of a human femur is investigated for both static and dynamic condylar loadings. An elastic bi-medium structure composed of compact and cancellous bone is used to represent the femur.

Critically stressed locations are identified and associated static and dynamic load levels which may initiate femur fracture are calculated. The predicted fracture sites and load levels are found to be in good agreement with published data for cadaver knee impacts. An important conclusion of this investigation is that the peak stress or strain and therefore femoral tolerance significantly depends on the impact duration due to stimulation of structural resonances.