Development of a new femoral component for patellofemoral prosthesis

The purpose for this work was to analyze the structural effects of the implantation of contemporary patellofemoral prosthesis on femur cancellous bone. In fact, studies on the state of strain/stress on patellofemoral arthroplasty are still very limited. The influence of the geometry and rigidity of the bone-implant interface is discussed, applying the Finite Element Method. One of the major reasons for the failure of currently available knee implants is the stress shielding effect. In loading situations, the bone is less requested, so the rate of bone remodeling decreases. The results showed that elastic strain is lower on bone areas close to the studied models of patellofemoral prosthesis, on the period after the implantation. Later on, bone rupture by fatigue may also occur, due to high strain, particularly on the models with fixation pins for the prosthesis. Furthermore, contact analyses showed that stability is best promoted without fixation pins.Fundação para a Ciência e a Tecnologia (FCT