Finite Element modelling to predict wear in joint replacements

Wear is the main cause of failure of prosthetic implants, for this reason, it is important to invest in this research field and study possible causes of implant failure in order to prevent negative outcomes after joint arthroplasty and increase the lifespan of the artificial joint. The techniques commonly used to measure this phenomenon involve the use of hip simulators, which, however, are expensive and time-consuming and do not take into account the high variability between different patients. A valid alternative to experimental tests in the laboratory is the use of computational methods, also called in silico, based on finite element models (FEM). These methods are faster and cheaper in providing wear predictions. In addition, on the contrary to hip simulators, can simulate different loading and kinematic conditions of the system. This thesis project aims to deeply investigate FEM for modelling the wear phenomenon in THR in order to develop a computational method that can be used to support and accelerate wear tests performed with hip joint simulators at the Rizzoli Orthopaedic Institute in Bologna. In the first part of the paper, I validated experimental tests of pin on disc and pin on plate with unilateral wear. Afterwards a test of pin on plate with bilateral wear. In the final part of the thesis, I was involved in an experimental study of hip prosthesis with realistic boundary conditions given by a hip simulator.