Implant research breakthrough at UL

Researchers from the University of Limerick have found a way to improve the lifespan of orthopaedic implants which will reduce the risk of infection and the need for secondary surgical procedures.

Dr Maurice N Collins of the UL research team said: “Currently some orthopaedic materials have failure rates of 13% over five years and our research hopes to explain the failure mechanisms in these materials in order to positively impact on the longevity of implants.”

The researchers have explored a link between sterilisation methods and wear in the polyethylene based material called ultra-high molecular weight polyethylene which is predominantly used in artificial joints. The material provides a bearing surface against which hard metal or ceramic components connect.

Before surgery, these components are sterilised by gamma radiation and this causes complex material interactions that ultimately change the mechanical properties of the bearing material by increasing its stiffness and brittleness. Consequently, wear rates are also changed by sterilisation processes, and the subsequent generation of wear debris has been implicated in artificial joint loosening and infection.

For this study, the experimental work was carried out using the Diamond Light Source particle accelerator in Britain, and the data analysis systems available at that facility allow results to be looked at in new ways which enables the study of fundamental material properties as a function of sterilisation dosage.

The research team consisted of Dr Collins, Dr Eric Dalton, Barbara Schaller of the Stokes Institute, and Dr JJ Leahy of the UL department of chemical and environmental science.