RESEARCH CARRIED out by the University of Limerick could prolong the life of implants of orthopaedic patients, according to its findings.
The information could also lead to improvements in patient recovery, reducing the risk of infection, and ultimately reducing the need for secondary surgical procedures.
Approximately 750,000 orthopaedic implant operations are undertaken in the United States each year. By 2030, this figure is expected to increase to 4.5 million.
The US hip and knee market for implants and devices was estimated at $6.4 billion (€4.8 billion) in 2009.
Dr Maurice N Collins, of the Stokes Institute at the University of Limerick, explained: “Currently some orthopaedic materials have failure rates of 13 per cent over five years. Our research hopes to explain the failure mechanisms in these materials in order to positively impact on the longevity of implants.”
The research team in Limerick has 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 which 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 in causing infection.