Lubrication and wear modelling of artificial hip joints: A review

Artificial hip joints, though a surgical success, are not a completely satisfactory engineering result, mainly because of their tribological performance. In fact the critical issue for implant success is the adverse tissue reactions to wear debris, which causes loosening and implants failure. Therefore the importance of biotribology comes rather straightforward and is proved by the huge number of papers on wear and lubrication of artificial joints published in the last ten years, mostly on experimental tests. However prostheses design can take advantage also of theoretical/numerical models for investigating the effects of geometrical and material parameters and for inferring long-term behaviour from short-term experimental results. This paper presents a detailed survey on recent lubrication and wear models, the latter being an important progress in biotribology. An accurate description both of methods and results is reported, stressing simplifying hypothesis and model input data to make their comparison easier. The aim of this review is to help research in this field, by defining the actual scenario where the way for new design solutions could be found