A FEM comparison of wear in two metal-on-metal total hip prostheses

The contact mechanics of two metal-on-metal (MOM) total hip prostheses was studied by means of the finite element method (FEM). The purpose of the work was to compare two total hip replacements (DuromTM and MetasulTM) with regard to the amount of wear debris released. Wear on the bearing surfaces was evaluated following Reye hypotheses from the pressure distribution, computed by means of three-dimensional FEM models; an approximate analytical model based on Hertz contact theory has also been developed and discussed. The results show that in the dry friction condition the DuromTM joint releases almost twice as much wear volume as produced by the MetasulTM joint. Therefore, while DuromTM implants can improve hip stability by increasing the prosthetic impingement-free range of motion (PIF-ROM), MetasulTM prostheses can be a valuable solution whenever wear represents a critical choice factor.