Oil Rig Tests Inform Joint Failures

What does the corrosion in the legs of oil rigs in sea water have to do with failing hip implants? Quite a lot, believe some surgeons who are using the technology developed to test oil rig corrosion to do the same thing for their hip implant patients. The team at Southampton General Hospital, United Kingdom, works on patients who require more surgery after the failure of their original implant operation. But instead of merely removing and replacing the failed artificial joints, they run the retrieved implants through a series of laboratory tests, similar to those run on oil rigs, to find out why a particular implant material failed in a patient.

The effort developed as a result of widespread concern over the effectiveness of metal-on-metal hip replacements, with research suggesting that more than a quarter of some devices had failed within five years. Jeremy Latham, M.D., a consultant hip surgeon, leads the team which includes clinicians, scientists and engineers.

“The last few years have been very difficult, particularly for patients with failing metal-on-metal hip replacements, ” he said.” By looking in great detail at the reasons why they’ve gone wrong, we hope, in the future, to be able to tailor treatment to the individual.” Working with Robert Wood, director of the National Centre for Advanced Tribology at the University of Southampton, the team has adopted the oil rig corrosion techniques to help understand the causes of failure in joint replacements.

As reported by Yahoo News of the UK and Ireland, the team has access to a measuring tool to produce instant 3D readings of wear and damage. A specialist in surface bacteria—biofilm—is able to examine devices for evidence of hidden infections or allergic reactions which can cause joint replacement failure.

Richard Oreffo, chair of musculoskeletal science at the University of Southampton, is developing a test to determine in advance whether or not a particular patient will react negatively to the materials in a joint replacement.

“Previously, patients with failed replacements had them removed and then replaced with similar devices. Tests showed only how the devices failed and not why, ” Latham explained.

“With our approach, we hope to be able to build profiles specific to each patient to the point where we can say ‘we are sure that a certain type of implant won’t work for you because you might react to it, but a different one will work perfectly well because you won’t react’. It is all about creating bespoke treatment by matching the implant to a patient rather than patient to implant.”