A numerical study of non-Newtonian transient elastohydrodynamic lubrication of metal-on-metal hip prostheses

This paper presents a comprehensive numerical study of transient non-Newtonian elastohydrodynamic lubrication of metal-on-metal hip prosthesis subjected to two different gait cycles. The shear-thinning property of the synovial fluid was found to have a significant effect on the lubricating film, in terms of both the magnitude and location of the minimum film thickness, and more generally the film thickness distribution. A range of clearances between the acetabular cup and femoral head was investigated and the shear-thinning effect was more pronounced in the hip replacements with smaller clearances.