One of the most troubled orthopedic implants of the past decade, this artificial hip — known as the A.S.R., or Articular Surface Replacement — was originally promoted as a breakthrough in design that would last longer and provide patients more natural movement.
But many patients soon developed inexplicable pain, and surgeons, when replacing the implant, discovered mysterious masses of dead tissue near the thighs of some patients.
Until late summer, officials at the Johnson & Johnson unit, DePuy Orthopaedics, the largest maker of replacement hips worldwide, maintained that the A.S.R. was performing on a par with competing devices. But interviews with doctors indicate that DePuy received repeated warnings that the implant was failing and that surgeons were abandoning it.
The brief and troubled life of DePuy's A.S.R. hip points to a medical implant system that is piecemeal and broken on many fronts, critics say. Unlike new drugs, many of which go through a series of clinical trials before receiving approval from the Food and Drug Administration, critical implants can be sold without such testing if a device, like an artificial hip, resembles an implant already approved and used on patients.
That way, manufacturers can rapidly make small changes to a device to improve it. But those simpler procedures have also effectively created a loophole, experts say, that lets producers bundle a component from an unapproved implant into an existing design and sell a device with minimal testing. With the A.S.R., that process unfolded with devastating results.
"You are basically testing these devices in an uncontrolled way on a large number of people," said Dr. Sidney M. Wolfe, the director of the Public Citizen's Health Research Group and a longtime F.D.A. critic.
Officials at DePuy declined to be interviewed for this article or to respond to specific written questions. In the past, they have said that the company moved promptly to take appropriate action on the A.S.R.
Late last year, DePuy announced that it was phasing the device out, but asserted at that time that the decision reflected lagging sales, not safety issues. And some doctors report good results with the implant.
"We believe we made the appropriate decision to recall at the appropriate time given the available information," DePuy said in a recent statement.
The faulty DePuy device is one of a number of Johnson & Johnson products that have come under intense scrutiny in the last year, because of defects or manufacturing flaws that have prompted recalls of such household names as children's Tylenol to Rolaids.
DePuy officials cannot say how many patients in this country received an A.S.R. because the company, like other orthopedic makers, does not track such implants. The Johnson & Johnson unit sold two versions of the A.S.R. hip, one that the F.D.A. never cleared for sale in the United States and one that it did.
DePuy officials estimated that about one-third of some 93,000 patients worldwide who received some version of the implant were in the United States. Both versions of the A.S.R. shared a common component, a so-called cup, or the part of the joint that replaces a patient's hip socket. It was that cup's design, experts say, that would prove faulty.
As patients began complaining, doctors and regulators here remained largely unaware that the problem was widespread because no independent monitoring system exists in this country that tracks implant failures. Such a database, used in other countries, might have clued in American orthopedists to the problem. In addition, doctors who tried to sound an alert said they had been rebuffed by DePuy.
The director of Australia's orthopedic database said he believed that DePuy had been less than forthright about the A.S.R. Data in that country, he said, showed that in 2008 the A.S.R. was failing early at a rate higher than some competing devices.
"When it is clear to the orthopedic community that a company has not been honest, that is a problem," said Australia's registry's director, Dr. Stephen Graves. "I think that J.& J. has a major issue with DePuy."
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http://www.nytimes.com/2010/12/17/business/17hip.html?nl=todaysheadlines&emc=a25&pagewanted=all
