By Toni Clarke
Jan 17 The U.S. Food and Drug Administration has
issued a proposal calling on companies that make all-metal hip
replacements to provide additional information proving they are
safe and effective before being allowed to continue selling
The move follows years of concern within the medical
community over the metal-on-metal implants, which the FDA said
on Thursday can cause soft-tissue damage, potentially leading to
further surgery to replace the devices.
All-metal hip implants were developed to be more durable
than traditional implants but have become a major cause of
concern after they were shown to fail at a higher rate than the
traditional hip replacement devices. Traditional implants
combine a ceramic or metal ball with a plastic socket.
The proposal will take time to implement - up to a year
according to Dr. William Maisel, deputy director for science at
the FDA's center for devices and radiological health. In the
meantime, he said, physicians should only use metal-on-metal
implants as a last resort.
"They should be rarely used, if at all, because there are
good alternatives available," he said.
As many as 500,000 Americans are estimated to have been
implanted with metal-on-metal hip replacements. Over the past
few years an increasing body of evidence has shown that the
devices may cause multiple health problems.
Johnson & Johnson, the largest manufacturer,
withdrew its ASR hip system in 2010 after it was shown to fail
at a higher-than-expected rate. It faces more than 2,000
lawsuits from patients claiming to have been harmed.
At their height, all-metal implants accounted for as many as
30 percent of artificial hips implanted in the United States
each year, published reports show. That figure has dropped down
to about 5 percent, Dr. Maisel said.
REGULATING MEDICAL DEVICES
Medical devices first became regulated in 1976 under an
amendment to the Food, Drug and Cosmetic Act. The rules placed
products into categories based on their perceived level of risk.
A low risk product such as a stethoscope would be required
to meet a general set of good manufacturing standards but would
not require much more to be allowed on the market.
A moderate risk product, such as a catheter, might have to
meet additional sterilization standards, but would be cleared if
it could show it was "substantially equivalent" to a product
already on the market - a pathway known as 501(k).
A high risk product, such as implantable heart defibrillator
or a breast implant, would have to be proven safe and effective
in independent clinical studies before being allowed on the
In the wake of the amendment, the FDA was required to
classify products that were already on the market and either
call for additional clinical data for products considered high
risk, such as all-metal hip implants, or downgrade such
high-risk products to a lower classification.
But it has taken the FDA years to decide whether to make
these calls. In the meantime, potentially high risk products
have been allowed onto the market based on the pathway for
moderate risk products. They have not required independent
The proposal issued by the FDA on Thursday confirms that
all-metal implants should be considered high risk and it called
for independent data showing they are safe and effective. The
public has 30 days to comment. If the rule becomes final,
companies will no longer be able to sell the products without
conducting new clinical studies.
Five U.S. companies make all-metal implants: Biomet Inc,
which was acquired by private equity consortium LVB Acquisition
in 2007; Encore Medical, which became part of Reable
Therapeutics and eventually merged with medical device maker DJO
Global; Wright Medical Technology Inc ; Zimmer Holdings
Inc and Johnson & Johnson's DePuy unit.
Lorie Gawreluk, a spokeswoman for DePuy, said that during
the review process, "the company will continue to comply with
all applicable regulations."
A spokesman for Biomet, Bill Kolter, said only that the
company is studying the proposed rule. Wright Medical declined
to comment. Zimmer was not immediately available to comment.
With wear, all-metal implants can shed metal where two
components connect, potentially damaging bone and soft tissue
surrounding the implant. ().
The FDA said it does not have enough data to specify the
concentration of metal ions in a patient's body or blood
necessary to produce adverse effects.
The reaction seemed to be specific to individual patients,
the FDA said on its website.