Oxford doctors develop important new test for knee replacement patients
Doctors in Oxford are devising an important new test which will actively benefit the 30,000 people in the UK who have knee replacement surgery every year in the UK.
Thanks to a grant of £136,725 from medical research charity the Arthritis Research Campaign, a team at the Nuffield Orthopaedic Centre will develop a new system for measuring the effectiveness of numerous knee replacement techniques currently being used.
"There are currently about 40 different total knee replacements available on the market in the UK, and that number is rapidly increasing," explained David Murray, consultant orthopaedic surgeon at the Oxford Orthopaedic Engineering Centre. "The majority have no published results, and while most work very well, some will be unsatisfactory with high long-term failure rates, and a few may be a disaster.
"New knee replacements are usually released onto the market after only one or two years of clinical assessment, which is unlikely to identify problems, so unsatisfactory knees will continue to be introduced. It's therefore essential that we implement better systems of early clinical assessment."
With ARC funding, Mr Murray and his team have already developed a system called Roentgen Stereophotogrammetric Analysis (RSA) over the past seven years, which is able to assess a hip replacement within two years and predict how well it will function in the long term. The Oxford team will now develop a similar RSA system for knees over the next two years. Initially they plan to study 75 patients with successful knee replacements.
"Total knee replacements fail either because they wear out or become loose," added Mr Murray. "RSA is an accurate 3D measurement technique using stereo X-rays. By measuring the movement of the implant components relative to the underlying bone we can predict loosening. By measuring the penetration of one component into another we can measure wear.
"We hope our new system for assessing total knee replacement will be as successful as the system for assessing hip replacements."
