FDA probes safety issues with metal hip implants
By Matthew Perrone Boston Globe
AP Health Writer / June 25, 2012
(FiDA blog bold)
WASHINGTON—Metal hip replacements implanted in a
half-million Americans may be failing earlier than expected, but it could be
years before U.S. health regulators have a clear picture of the problem.
The
Food and Drug Administration holds a two-day meeting starting Wednesday to
scrutinize the safety of metal-on-metal hip implants, following years of
patient reports of pain and swelling that sometimes requires removal of the
devices. It is a challenging, but familiar, predicament for the FDA: reviewing
the safety of a device that was expected to be superior, but which may actually
be more dangerous than what came before.
For decades nearly all orthopedic implants were
made from plastic or ceramic. But in the last 10 years some surgeons began to
favor implants made with metal stems and sockets. Laboratory tests suggested the devices would be more resistant to
wear and reduce the chances of dislocation.
But recent data gathered by surgeons in the U.K.
appears to show just the opposite.
In March, British
experts at the world's largest artificial joint registry told doctors to stop
using metal-on-metal hip replacements, citing an analysis showing they have
to be replaced more often than other implants. Hip replacements are supposed to
last between 10 to 15 years, but more than 6 percent of patients with metal
hips needed them replaced after less than five years. That compared with just 2
percent of people who had ceramic or plastic joints. Both types of devices are
prescribed for people suffering hip pain and limited movement due to arthritis
or injury.
British regulators now recommend that people who
have the implants get yearly blood tests
to make sure no dangerous metals are seeping into their bodies as the
components rub against each other.
The
FDA has not made any recommendations of its own for the estimated 500,000
American patients with the devices.
FDA scientists say they want to consider all
available information before making their recommendations -- not just the data
from the U.K.
"Why look at a single registry when there's
data from around the world?" said Dr.
William Maisel, FDA's chief scientist for medical devices, in an interview
with the Associated Press. "This is an opportunity for us to look at all
the available information so that we can have a thoughtful conversation about
what clinical recommendations can be made."
Maisel said the FDA is working to combine data
from foreign countries and the U.S. to determine which groups of patients and
implants are most problematic. On Wednesday and Thursday the FDA will ask a
panel of experts to recommend the best practices for monitoring patients with
the devices. Panelists will consider blood tests, medical imaging and
laboratory tests.
But some U.S. orthopedic specialists say they
have already reached their own conclusions about metal hips.
"In my personal opinion there is very little
room, if any, for metal-on-metal implants because the alternatives we have on the market are likely safer and as
effective," said Dr. Art Sedrakyan, professor of public health at
Weill Cornell Medical College in New York.
The FDA's deliberative approach to tackling the
hip implant issue is in some ways a necessity. Unlike other countries, the U.S. has no national registry to
track the performance of implants over time.
The FDA received 16,800 negative event reports
involving metal hips between 2000 and 2011, but regulators stress that number
is not very useful. Many doctors do not
report problems to the FDA, and the volume of reports is influenced by news
reports on safety issues.
A registry set up by Minnesota's HealthEast Care
System recorded four times as many
replacement surgeries for patients with metal-on-metal hips as those with other
implant types. However, a similar registry set up by health care provider
Kaiser Permanente found no difference between the two groups.
With little definitive data on U.S. hip implants,
the agency has asked manufacturers like Johnson & Johnson, Zimmer Holdings
Inc. and Biomet Inc.
to conduct long-term, follow-up studies of more than 100 metal-on-metal hips on
the U.S. market.
FDA scientists say the studies will help
"fill in the blanks" on a number of scientific questions, including
the effects of metal particles that often seep into the bloodstream as the
implants wear down.
But Sedrakyan and others say it could be a decade or more before that information is available.
In a commentary published last week in the New England Journal of Medicine,
Sedrakyan and two co-authors pointed out those studies must run at least eight
years to return the information FDA is seeking. Based on the authors' analysis
of FDA records, the FDA has reached agreements on the design of less than 25
percent of the studies, and it's unclear whether any of the studies have
actually begun. The FDA notified the companies last May.
The prospect of safety findings arriving in eight
or 10 years is little comfort to
patients like Mary Weaver, 48, who had both hips replaced with a metal
implant from Johnson & Johnson in 2007 and 2008. J&J recalled the ASR
hip replacement in 2010, after reports that it was failing in some patients
after only a few years of implantation.
Due to increasing pain and elevated metal levels
in her blood, Weaver had both implants removed in 2011. She was let go from her
job due to the time needed to undergo both surgeries, and is currently
unemployed.
"I hope that no one has to go through this
-- it's frustrating, it's emotionally draining," said Weaver, who lives in
Mount Jackson, Va. "It's not just hard on you, it's hard on your whole
family because your quality of life is not what it used to be."
Like
90 percent of medical devices sold in the U.S., most metal-on-metal hips were
approved via the FDA's fast track program for medical devices. Under the
so-called 510k system, the agency waives clinical testing requirements for
devices which appear similar to others already in use. Since plastic and
ceramic hip replacements had been on the market since the 1950s, most metal hip
replacements were approved without new clinical testing.
"I
am so furious they would use my wife as a lab rat, along with the other 500,000
people who don't have a clue what is happening," said
Dwight Schrag, 69, of Bellevue, Wash. Schrag's wife Mary received J&J's ASR
hip in 2006 and had it removed due to pain and other side effects in 2010.
Schrag is one of a number of speakers who have signed up to speak during a
public comment session at the FDA meeting.
It's not the first time the FDA's fast-track
program for clearing devices has come under fire.
Last
summer the Institute of Medicine said in a report that the FDA should abandon
the 35-year-old system because it provides little assurance that the implants
are actually safe. The Institute is composed of medical experts who advise the
federal government.
Although
the FDA itself requested the report from the Institute, agency officials
rejected the group's conclusions, saying the 510k system works well for the
vast majority of devices.
explanthis comment: FiDA blog/Joleen Chambers
The profitable medical device industry has conflated justice so completely that the American citizenry blindly pays for the #1 expenditure of Medicare: joint replacements. The industry has so many entitlements: no warranty on product, no clinical testing, no national registry, no need to report adverse events, pre-emption in state court because of FDA, no compensation to victims of failed products without a David/Goliath courtroom battle and unrestricted direct-to-consumer marketing. Even with all these advantages, the industry fights a tax that would help fund the FDA/CDRH. Do they not have faith that they can make $$ and produce a safe and effective product? Consumer beware!
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