With Warning, a Hip Device Is Withdrawn

The action by the company, DePuy Orthopaedics, follows more than two years of reports that the hip implant, which is known as the ASR, was failing in patients only a few years after implant, requiring costly and painful replacement operations.

Some orthopedic experts have voiced dismay in recent interviews that DePuy had not halted sales of the device earlier. And some specialists said that they believed the device had a design flaw that made it difficult to implant properly, a claim disputed by DePuy officials, who had said the product had no safety problems. The director of an implant database in Australia, Dr. Stephen Graves, said the data had shown for some time that the ASR had been failing early at a significantly higher rate than some competitors’ devices. In December, DePuy voluntarily withdrew the ASR from the Australian market.

DePuy, of Warsaw, Ind., also announced late last year that it planned to phase out sales of the product worldwide by the end of 2010.

“It is way too late,” Dr. Graves said.

While the ASR is not widely used in the United States, DePuy officials said recently that it had been implanted in thousands of patients worldwide.

In a letter dated March 6, DePuy told doctors that recently analyzed data from Australia suggested that the ASR had a higher-than-expected failure rate when used in traditional hip replacement on certain types of patients. The letter said that the data shows that the risk is highest for patients of small stature, a group that typically includes women, and patients with weak bones.

Asked Tuesday by a reporter why the company was issuing the advisory now, even as it was winding down sales of the device, DePuy said in a statement that it believed that “this is new and important information surgeons who continue to use ASR should have to inform their clinical decision making.”

The ASR, one of several hip models sold by DePuy, belongs to a category of devices known as metal-on-metal implants.

Such implants are under increasing scrutiny because they can generate large amounts of metallic debris as they wear. The debris can cause severe inflammatory responses in some patients, damaging muscles and other soft tissues, requiring a follow-up operation to replace the device soon after implant — instead of the 15 or more years artificial hips are supposed to last.

Just last month, in an interview, DePuy officials defended the ASR’s track record, saying its performance equaled that of competing devices. Those officials also said that the company was phasing out sales of the ASR for commercial reasons, not because of any safety issues.

“With declining sales of this particular product in its market segment, we are focusing on newer technologies,” Sally Hunter, DePuy’s worldwide vice president for regulatory affairs, said last month.

DePuy sells the ASR for use in hip “resurfacing,” a popular alternative to traditional replacement. The company also separately markets an ASR component — its hip socket, or cup — for use in traditional hip replacement. DePuy’s March 6 alert deals with the ASR’s failure rate in traditional replacements.

While the ASR resurfacing system has been used abroad, the Food and Drug Administration has not approved it for sale in the United States. In 2005, however, the F.D.A. cleared the ASR cup for use in traditional hip replacement. The device was cleared through a regulatory pathway that did not require it to undergo clinical trials.

Since the beginning of 2008, the F.D.A. has received about 300 complaints on the ASR involving patients in the United States who received it. A review of those reports indicates that a vast majority of those patients underwent an operation to have the device replaced soon after getting it.

The number of such complaints typically understates a product’s problem, however, because many doctors and hospitals never bother to file reports with the F.D.A.