The viscoelasticity of the UHMWPE liner may play an important role in the lubrication performance of soft artificial hip joints. All the previous lubrication analyses for UHMWPE hip implants assumed that the UHMWPE liner was linear elastic. In order to investigate the influence of viscoelasticity of the UHMWPE liner, a transient viscoelastic lubrication model was developed. The results showed that the viscoelasticity played a significant role in the lubrication performance of UHMWPE hip implants. Moreover, the retardation time and the ratio of loss and storage modulus of the UHMWPE liner had important effects on the lubrication performance of hip implants. These findings provide new insights into the lubrication mechanisms of UHMWPE artificial hip joints.

This is a repository copy of Towards the direct validation of computational lubrication modelling of hip replacements.

This paper reviews the recent advancements in computational modelling of the lubrication of hip and knee joint replacements, especially those concerning Professor Duncan Dowson’s contribution. The review starts with the development of modelling the five key parameters that appeared in the pioneered Hamrock–Dowson formula. Then, the theory and approaches for the mixed lubrication in which the artificial hip and knee joint replacements operate are reviewed. We also discuss the current challenges in modelling the lubrication behaviour of joint replacements and how these challenges could be addressed in future studies. These challenges include the mixed lubrication theory, the numerical complexities due to complicated realistic geometry, material and rheology, and individual physiological diversities.

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