Numerical study of surface texturing for improving tribological properties of ultra-high molecular weight polyethylene

Ultra-high molecular weight polyethylene (UHMWPE) has been used in total joint arthroplasty for over 50 years. Conventionally, smooth UHMWPE surfaces are used for total joint replacements; however, smooth surface contacts have been shown to be inadequate in friction reduction and/or anti-wear. More recently, micro-textured surfaces have been investigated for reduction of the friction and wear of two contact interfaces. Unfortunately, the tribological behavior of textured UHMWPE surfaces requires further research to understand its tribological behavior. A numerical model is presented to understand the potential use of specially textured surfaces to improve the tribological properties of UHMWPE. A two dimensional, transient form of Reynolds equation was used to model the lubrication condition of the textured surfaces. The effects of area densities and pore depths over varying diameters were examined for several textured geometries including circle, rectangle, square and triangle. The simulation results show that the surface texturing can effectively be used to enhance hydrodynamic effects. More specifically, it was shown that the rectangular surface texture displayed superior characteristics over the other geometries investigated. The results provide a theoretical reference for the tribological design of surface texture on UHMWPE.