Low success rates for new knee and hip replacements
Posted Nov 21 2008 4:29pm
A recent joint replacement study conducted by the Royal College of Surgeons has revealed that the latest surgical techniques used for hip or knee replacements have lower success rates than the older methods.
Over 16,000 NHS patients have hip resurfacing or partial knee replacements every year, but one in seventy five will have to undergo a revision of their joint replacement within three years of the surgery. Although the new technique has significant improvements in mobility and a quicker recovery rate, research has revealed that the joints are twice as likely to fail compared with the older, traditional joint replacement. This news will affect thousands of patients, all of whom will have had high hopes for the longevity their new mobility.
The traditional surgical technique involved a complete replacement of the whole joint. It had previously been expected that the new procedure, which uses plastic, ceramic or metal prosthetic joint would last 10 to 15 years. However, patients are finding themselves readmitted to hospital for surgery, particularly those who had hip resurfacing and unicondylar knee replacements.
Revision rates were highest among women who had undergone hip resurfacing. This is attributed to women having on average, weaker bones than men. Jan van der Meulen, who led the study from the London School of Hygiene and Tropical Medicine, explained: “On the basis of our data, consideration should be given to using hip resurfacing only in male patients and unicondylar knee replacement in elderly patients.”
Consultant orthopaedic surgeon, Graham Gie, commented: “Hip resurfacing has only been around since the Nineties but it has been directly marketed to younger patients, in particular, as offering them a more active lifestyle following surgery. There isn’t really the long-term evidence to back those claims up, while at the same time the metal on metal joint has created another type of failure – fracture of the femur.”
The conclusions from the research are supported by other research around the world. Gordon Blunn, a biomedical engineer at University College London, added that an indication for this particular type of hip resurfacing was for younger patients, usually up to 50 years old. He said: “About 50 per cent of hip replacement patients in this age group have resurfacing and the revision rate is about 5 per cent after eight years.”
The report is published in the journal PLoS Medicine.