Bone remodelling simulation: a tool for implant design

Although many inert materials have very complex behaviours, biological living materials are still more complicated. For example, bone tissue is a porous, heterogeneous and anisotropic material, which modifies its properties in accordance to the stress level, presenting an evolutive behaviour known as adaptive bone remodelling. In this work, this special behaviour has been studied, including a brief review of the main bone remodelling models. These mathematical formulations have been implemented in finite element code to predict the bone behaviour when an artificial fixation or prosthesis is implanted. The main aim of this paper has been the qualitative computational study of the long-term bone evolution, specially of the human femur, when different types of implants are employed to stabilise several kind of fractures. A comparative analysis between two total hip resection prostheses widely used, like the Exeter and the SHP, has been performed. We have also studied the treatment of proximal femoral fractures fixated by extramedullar and intramedullar implants. Finally, distal fractures have been also analysed, when treated by plates (the Liss plate) or screws (the DFN system). This work shows the importance of computational simulation to predict both short- and long-term evaluation of different possible treatments in orthopaedics.