Research could increase the life of artificial joint implants

Working at the Diamond Light Source synchrotron facility in the UK, a team from Limerick University found that gamma rays used to sterilise parts of the implant actually make them more stiff and brittle.

Approximately 750,000 orthopaedic implant operations are undertaken in the US each year, in a market estimated to be worth $6.4bn (£4bn). However, research has shown that the failure rates of some orthopaedic materials is around 13 per cent over five years.

‘The polymer bearing material between the two metallic parts wears after a certain length of time and the joint becomes loose, so it has more room to move within the socket and little particles can chip off the polymer, causing pain and infection, that can lead to secondary surgeries,’ said Dr Maurice Collins from the Stokes Institute at Limerick University.

In the majority of artificial joints, ultra-high-molecular-weight polyethylene (UHMWPE) provides a surface against which hard metal or ceramic components connect. Before surgery, these components are sterilised by gamma radiation.