A recently recalled artificial hip made by a unit of , designed to last 15 years or more, is failing worldwide at unusually high rates after just a few years.
Faulty Hip Points to Broken U.S. Implant System
The Implants Loophole
By BARRY MEIER
Published: December 16, 2010
Doctors who have operated on patients to remove and replace faulty hip replacements have discovered metallic debris shed by the device destroying muscle and bone.
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 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 , 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. , the director of 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.”
Permanent Damage
For patients, the problems with the A.S.R. required additional painful operations in which the device was replaced with yet another artificial hip. For some, however, the damage to bone, muscles and nerves from the troubled device, which can shed tiny metallic particles, has left them permanently disabled. That damage can also complicate a replacement operation.
One patient, Mary Ann Doornbos, a former employee in Illinois, remains on disability and still walks with a cane, one year after her A.S.R. was removed and replaced.
Ms. Doornbos, 56, said that she could not stand up long enough to cook a meal because the pain was constant. “I have been told that I have to be prepared that it will be like this for the rest of my life,” she said.
Like thousands of other patients, Mrs. Doornbos did not know the hip component that caused her disability was a critical part of another device that the F.D.A. had never approved for sale.
Initially, DePuy developed the A.S.R. as a so-called resurfacing implant, a device comprising two components — the cup and a thigh component — that was used in a procedure in which less of a patient’s thigh bone was removed than in a standard hip replacement. And in 2003, DePuy started selling that version of the A.S.R. outside the United States.
But because resurfacing was a new procedure, the F.D.A. required DePuy to test the A.S.R. resurfacing implant in a clinical trial before it could sell it here. It was not until late 2007 that the company submitted that study data to the F.D.A. for review and possible approval, a process that was aborted last year when DePuy withdrew its application.
But back in 2005, the F.D.A. allowed DePuy to start selling the other version of the A.S.R., a modified standard hip replacement that used the same A.S.R. cup found in the company’s unapproved resurfacing device. As a result, tens of thousands of patients here like Ms. Doornbos would get that version of the A.S.R.
Current rules do not require device producers to notify the F.D.A. when they bundle together components from approved and unapproved devices, Mark Melkerson, an agency official, acknowledged. New iterations of device designs already used on patients typically receive scant scrutiny from the F.D.A. before going to market.
An internal agency review released several months ago found numerous flaws with the process, and the F.D.A. is proposing changes to it. To win agency permission to market the A.S.R. in the United States, DePuy never had to perform any patient testing of it. Agency officials said the company cited clinical data it had used five years earlier to win F.D.A. approval to sell another all-metal hip implant called the Ultima. The Ultima, however, used a cup that had a totally different design than one used with the A.S.R.
The F.D.A. also allowed another orthopedics company, , to sell a cup used in its unapproved hip resurfacing implant as part of a standard hip replacement. Hundreds of patients who got that component, which is known as the Durom, have also been forced to undergo early second operations after it failed not long after the first implant.
As for Ms. Doornbos, her surgeon simply told her in 2007 that he expected that she would not have to worry about a new hip for a long time.
“My doctor said that this was a new design that was particularly good for young people,” she recalled.
Grave Concerns
It also was in 2007, the same year that Ms. Doornbos got her new hip, that an orthopedic surgeon in northeastern Britain, Dr. Antoni Nargol, would start seeing a few A.S.R. patients complaining of . But two years later when Dr. Nargol and a colleague say they told DePuy officials they had found an explanation for why the A.S.R. was failing in patients, the company did not stop selling it or issue a warning.
Instead, the men said they were met with a response similar to one that other orthopedic surgeons who have tried to sound alarms encountered — a claim that the fault was not related to a particular device but to a doctor’s surgical technique.
“They basically said that the problem was me,” said Dr. Nargol who practices at a hospital in Stockton-on-Tees, a small industrial city south of Newcastle.
Dr. Nargol started as a believer in the A.S.R., not a critic; today both he and a colleague, Dr. David Langton, are consultants to lawyers suing the company.
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