Wednesday, October 3, 2012
Warning Issued on Alternative Hip Replacement Procedure
A major study released on Monday urged women to avoid an alternative hip replacement procedure known as “resurfacing” and also recommended against its use in smaller men.
The study reflected the experiences of some 32,000 patients followed by the National Joint Registry of England and Wales. The report was sponsored by the British registry and published in a medical journal, The Lancet.
The researchers, headed by Dr. Ashley W. Blom of the University of Bristol, concluded that resurfacing had an “unacceptably high” early failure rate in women when compared with traditional hip replacement. The early failure rate was also higher in smaller men.
Traditional hip implants are supposed to last 10 years or more before requiring replacement. But the only class of patients in which the durability of a resurfacing was on a par with a traditional plastic-and-metal implant was middle-aged men of larger stature, the study found.
The new report is in keeping with earlier findings about resurfacing, a procedure that preserves more of a patient’s thigh bone than a conventional hip replacement.
Some device makers and surgeons heavily promoted the technique as a breakthrough that would allow younger patients to remain more active. But the procedure’s popularity has fallen in recent years as concerns about it have grown.
Resurfacing devices belong to a class of products know as metal-on-metal implants in which both the cup and ball of an implant are made of metal. Over the last two years, the use of all-metal implants has largely ceased because of evidence that they generate metallic debris as they wear, damaging tissue and muscle.
In a commentary accompanying the new report, an expert in this country, Dr. Art Sedrakyan, noted that the apparent failure of resurfacing devices raised questions about how such products were reviewed by the Food and Drug Administration.
“If hip resurfacing devices are found to be unsafe, then the implications are grave,” wrote Dr. Sedrakyan, a researcher at Weill Cornell Medical College of Cornell University.
While traditional all-metal implants were marketed in this country with little testing, the F.D.A. required producers to run clinical trials of resurfacing implants before they were sold here. As a result, patients who got traditional metal hips that failed can sue their manufacturers, while those patients who got a resurfacing that failed are barred from doing so.
Companies that market resurfacing devices such as Smith & Nephew, which sells a product known as the Birmingham implant, have repeatedly argued that the devices are not prone to the same problems as traditional all-metal implants. And some patients who got a resurfacing have also said that it has allowed them to participate in more physically demanding activities, like skiing.
In a statement, Smith & Nephew said that the new report underscored the company’s longstanding position that “patient selection” is important to the success of the Birmingham device.
“In the right patients, it has a record of superior clinical performance,” the company said.
Dr. Blom, the British researcher, reported that data showed the Birmingham device was used in about 50 percent of all resurfacing procedures captured by the registry.
Posted by Connie at 3:44 PM