LONDON, UK—About half of all primary hip or knee replacement operations—1 in 75—carried out on patients in the UK require a revision joint arthroplasty after 3 years, a rate which is considered relatively low, according to a new study in the September 2008 issue of PLoS Medicine.1 The study is based on data from the National Joint Registry for England and it reinforces concerns about the new surgical techniques of hip resurfacing and unicondylar knee replacement. The researchers emphasize the need for national joint registries to better evaluate current available prostheses and improve patient selection.

“It is essential to continue following up these patients to assess whether these differences remain beyond the first 3 years because it has been shown that risk factors for revision as well as reasons for revision change with time after the joint replacement.”—Nokuthaba Sibanda, PhD
Cemented knee or hip prosthesis had the lowest overall revision rates; women who had undergone hip resurfacing rather than total hip replacement had the highest revision rates. Of patients who had undergone knee replacement operations, those who had unicondylar prostheses had the highest revision rates, found researchers led by Nokuthaba Sibanda, PhD, of the London School of Hygiene and Tropical Medicine in the UK.

“[I]t is essential to continue following up these patients to assess whether these differences remain beyond the first 3 years because it has been shown that risk factors for revision as well as reasons for revision change with time after the joint replacement.”

National Joint Registry maps revision trends

The researchers linked 167,076 records from the databases to determine revision arthroplasty rates in England and Wales between April 2003 and September 2006. There was no connection between a patient's age and revision rates for hip replacements, whereas revision rates after knee replacement decreased strongly with age.

As a result of the new findings, “consideration should be given to using hip resurfacing only in male patients and unicondylar knee replacement only in elderly patients,” the researchers concluded.

Studies such as this one “offer evidence about how effective a registry can be at identifying problems earlier and this can save a lot of patients from being exposed to faulty devices,” said Joshua Jacobs, MD, professor and chair of orthopaedic surgery at Rush University Medical Center in Chicago. “A national joint replacement registry could be very beneficial for patients, orthopaedic surgeons and the industry.”

Reference
1. Sibanda N, Copley LP, Lewsey JD, et al. Revision rates after primary hip and knee replacement in England between 2003 and 2006. PLoS Med. 2008;5:1-11.