FEM wear prediction of ceramic hip replacement bearings under dynamic edge loading conditions

Hard-on-Hard hip implants, specifically ceramic tribo-pair, have produced the highest in-vivo wear resistance, biocompatibility, superior corrosion resistance, and high fracture toughness. However, this ceramic tribo-pair suffers from edge loading, sharply increasing wear and accelerating early implant failures due to micro-separation. Even though in-vitro studies have tested the occurrence of wear due to dynamic edge loading, the Finite Element Method (FEM) gives the advantage of accurately estimating the wear, minimizing the experimental time and cost. A new fundamental FEM model is developed to predict wear for ceramic hip replacement bearings under dynamic edge loading conditions for a fixed separation and fixed inclination angle. The model is directly validated with the existing hip simulator data up to 3 million cycles in terms of wear depth, wear scar and volumetric wear rate. The results from the model show that the accuracy in wear prediction was more than 98% for the wear depth and volumetric wear rate for the dynamic edge loading condition. A stripe wear scar is captured, depicting the edge loading conditions. The developed model from this study can predict wear under pure standard and dynamic edge loading conditions.