Biomechanical Modeling of Hip Joint Prosthesis

In this work a Bombelli cementless isoelastic RM total hip prosthesis was considered. It was implanted over a course of 14 years on the patient and studied subsequently to its chirurgical replacement. Computed Tomography, radiographies and 3-D laser scanning were used to assess the prosthesis geometry, while the original femur anatomy was modeled based on 2-D radiographies taken at different stages of the in-vivo implant of the prosthesis. A finite element model was developed, based on the generated 3-D geometrical model, considering a linear elastic behavior and typical loading conditions. This analysis allowed determining stress and strain fields throughout bone-prosthesis contact surface and critical areas in terms of micromovements. The developed procedure, consisting of 3-D scanning, generation of geometrical 3-D models and finite element analysis, results in a powerful tool to follow-up and predict failure mechanisms in hip joint prosthesis.