The federal government has received a surge in complaints in recent
months about failed hip replacements, suggesting that serious problems
persist with some types of artificial hips even as researchers scramble
to evaluate the health dangers.
An analysis of federal data by The New York Times indicates that the
Food and Drug Administration has received more than 5,000 reports since
January about several widely used devices known as metal-on-metal hips,
more than the agency had received about those devices in the previous
four years combined.
The vast majority of filings appear to reflect patients who have had an
all-metal hip removed, or will soon undergo such a procedure because a
device failed after only a few years; typically, replacement hips last
15 years or more.
The mounting complaints confirm what many experts have feared — that
all-metal replacement hips are on a trajectory to become the biggest and
most costly medical implant problem since Medtronic recalled a widely
used heart device component in 2007. About 7,700 complaints have been
filed in connection with that recall.
Though immediate problems with the hip implants are not
life-threatening, some patients have suffered crippling injuries caused
by tiny particles of cobalt and chromium that the metal devices shed as
they wear.
Hip replacement is one of the most common procedures in the United
States and, until a recent sharp decline, all-metal implants — one in
which both the artificial ball and cup are made of metal — accounted for
nearly one-third of the estimated 250,000 replacements performed each
year. According to one estimate, some 500,000 patients have received an
all-metal replacement hip.
One of the most problematic devices, the A.S.R., or Articular Surface
Replacement, was recalled last year by Johnson & Johnson and accounted
for 75 percent of the complaints reviewed by The Times. A precise count
of failed implants reported to the F.D.A. is hard to come by because of
the agency’s overlapping reporting system, though The Times sought to
eliminate duplicate reports about the same incident. Some complaints
came from outside the United States.
Under F.D.A. rules, many all-metal devices were sold without testing in
patients or without a requirement that producers track their
performance. But in an unusual intervention, the F.D.A. in May ordered
producers to study how frequently the devices were failing and to
examine the threat to patients. Now, researchers say, producers face
substantial hurdles in recruiting the hundreds of patients needed to
conduct sound studies because of the lack of patient registries.
“They are grasping at how they are going to get this information,” said
Dr. Robert S. Namba, an orthopedic surgeon with Kaiser Permanente.
In addition, researchers are struggling to understand the tissue damage
caused by the metallic debris. While some patients experience pain,
other patients with the same damage have no pain, complicating decisions
about whether to remove devices.
As problems and questions grow, most surgeons are abandoning the
all-metal hips, saying they are unwilling to expose new patients to
potential dangers when safer alternatives — mainly replacements that
combine metal and plastic components — are available. Some researchers
also fear that many all-metal hips suffer from a generic flaw. Current
use of all metal devices has plummeted to about 5 percent of the market,
though a few of the models are performing relatively well in select
patients.
“It is like playing Russian roulette,” said Dr. Geoffrey H. Westrich, an
orthopedic surgeon at the Hospital for Special Surgery in New York, who
has stopped using all-metal implants.
Dr. William Maisel, the chief scientist of the F.D.A. division that
oversees medical devices, said he believed that producers would mount
rigorous studies and find answers. But he acknowledged that it could
take several years.
“There is not an existing infrastructure for studying this kind of
information,” Dr. Maisel said.
For many patients, it is too late. In 2008, Ann Morrison, a physical
therapist from Newark, Del., received all-metal replacements for both of
her hips. But Ms. Morrison, 50, soon experienced pain, rashes and
inflammation.
Last year, the devices were replaced, but by then, she said,
debris-caused tissue damage was so extensive that she now needs a brace
to walk and still cannot work. She called the F.D.A.’s order for medical
studies a “joke.”
“We will be the little crash test dummies here until they figure out the
health ramifications for us down the road,” said Ms. Morrison, who has
sued the DePuy division of Johnson & Johnson, which made her implants.
To conduct its analysis, The Times reviewed complaints filed with the
F.D.A. from 2007 through this June for several implants, including the
A.S.R. and the Durom cup, a component sold by Zimmer Holdings.
Typically, the number of complaints filed with the F.D.A. about a
product understates a problem because while companies must file reports,
doctors and patients do not have to. The filing volume for the A.S.R.
and the Durom cup probably reflects a surge of lawsuits filed against
their makers.
The Times review found some 7,500 complaints about the A.S.R., nearly
5,000 of them coming since January. In the case of the Durom cup, about
1,600 complaints were filed with the regulator from 2007 to this June.
Because complaints to the F.D.A. are not uniform, it is impossible to
say how many adverse reports about all-metal hips have been submitted.
For example, the Times analysis found some 200 complaints about an
all-metal version of another DePuy device called the Pinnacle as well as
400 additional complaints that noted metal-related problems in Pinnacle
patients. But the Pinnacle is sold in several versions, so it was not
clear how many of the metal-related complaints were linked to the
all-metal device.
A spokesman for Zimmer Holdings said the Times review was “in the
ballpark” of the company’s assessment of the drug administration’s
filings. A DePuy spokeswoman declined to disclose the number of A.S.R.
complaints that the company forwarded to the F.D.A. She maintained that
the Pinnacle was performing well.
DePuy, Zimmer and another producer of metal hips, Wright Medical,
declined to discuss the study proposals they had submitted to the F.D.A.
to comply with its May order. A fourth company, Biomet, said it had
proposed mounting a study of 400 patients who received its devices that
would draw in part on studies already under way. The F.D.A. declined to
release producers’ proposals, saying that they contained “confidential
commercial information.” The agency has until November to decide on the
plans’ adequacy.
In an effort to recruit patients, companies have recently contacted,
researchers said, health systems like Kaiser Permanente and hospitals
that operate their own implant registries.
Meanwhile, researchers say it may be a year before standard protocols
are formulated that may be central to the future studies, like a uniform
procedure to measure metallic ions in a patient’s blood or how to
calibrate diagnostic equipment to best detect tissue damage.
By BARRY MEIER and JANET ROBERTS
New York Times - Aug. 23, 2011
New York Times - Aug. 23, 2011
No comments:
Post a Comment