Design of human artificial hip joint replacements with wear control

Project ID: SST_2_6

The wear and wear particles of hip joint replacements is a main problem causing the failure. Wear particles are generated from the artificial materials during motion, and they have adverse biological reactions with the surrounding tissue and bone. However, wear cannot be completely avoided in artificial hip bearings as long as they are moving under loads. Although most of studies are towards how to minimise wear, this PhD project will develop a new strategy on how to control the wear. Control of wear particles is exactly what engineers have designed in industrial lubrication systems such as aircraft and automotive, which work under more severe conditions but resulting in almost zero wear.

This project aims to develop hip joint prostheses with a new concept of a ‘wear control system’. The objective is to control the wear particles within the hip implant to avoid direct contact to the periprosthetic tissue, so that unfavourite biological reactions and associated problems or the third body wear can be reduced. The target material combinations include metal (or ceramic) heads on polyethylene cups that associated with polyethylene wear particles. The project will include both numerical simulations and experimental test.

The numerical analysis will be based on previous thin-film lubrication model and will explore to the Computational Fluid Dynamics (CFD) models for particle immigration analysis. Numerical simulations will provide an optimisation on the design parameters of the control system, such as the location, shape and distribution. The experimental tests will include microfluidics flow test and joint wear simulator tests to evaluate the efficiency of the wear reduction.

The Engineering Department has the required software ANSYS Fluent and COMSOL Multiphysics, and experimental facility including the pin-on-disc wear test rig, 3D printing and optical lithography to manufacture the prototypes and conduct tests.

The wear simulator test based will be conducted by collaboration with the University of Newcastle and Orthotek lab at Shanghai University. The Orthotek lab at Shanghai is one of few labs in the biomechanical testing of implants and prostheses in China which has been accredited by ASTM and ILAC.

Applications should have a background in Engineering, Physics or Product Design. Experience with CFD simulation or fluid dynamics is beneficial, but do not need detailed knowledge of joint replacements before starting the PhD.

Supervisory Team:

Dr Leiming Gao, Department of Engineering

Prof Phil Breedon, Department of Engineering

Dr Lucas Goehring, Physics and Maths