By Taylor Lindstrom
A 30-year-old man needs a hip replacement. His surgeon recommends a
DePuy ASR XL Acetabular system
because its metal-on-metal design is more durable and allows for a more
active life. Following the doctor's recommendations, the young man gets
the DePuy hip implant.
Then the hip
implant fails. The young man is in extraordinary pain. His revision
surgery reveals dead tissue and deteriorated bone, making it extremely
difficult for his new implant to take hold. He takes a blood test that
reveals extremely elevated levels of cobalt and chromium. He is now
hypersensitive to metal and the surgeon warns him he may contract
early-onset osteolysis.
The
young man blames the surgeon for recommending the
ASR XL Acetabular
system in the first place? But the surgeon isn't the culprit in this
scenario; he made the best recommendation he could for his patient. The
surgeon is simply another victim of the real culprit: an FDA approval
loophole called "substantial equivalence."
A
surgeon has countless medical devices to choose from. In the world of
hip implants, he's looking at numerous options. The surgeon naturally
wants to give his patients the best implant possible for their
situation, so he chooses only FDA-approved devices that have been
rigorously tested for safety.
Or so he thinks.
Does an FDA Endorsement Guarantee Hip Implants' Safety?
In
the case of the patients who received an ASR XL Acetabular system, it
may have been the difference between an improved quality of life with a
working hip implant - or a drastically reduced quality of life with a
faulty one.
The premarket notification process is also known as the 510(k) process, and it includes the loophole of "
substantial equivalence."
The 510(k) process allows a product to go directly to market without
full clinical testing if the manufacturer claims the medical device is
"substantially equivalent" to another device already on the market.
According
to FDA documents, a substantially equivalent product is one that is
created for the same intended use as the previously approved products;
has the same design, materials and technology; and raises no new
concerns about safety or effectiveness.
Substantial
equivalence was designed to prevent the 2-3 year waiting period for
testing. If one hip implant is so similar to another device that it
could be expected to get the same test results, what was the point of
testing it?
One might argue "safety,"
but one would be naive to do so. Medical device companies pushed for
the substantial equivalence loophole for an entirely different and far
less altrustic reason: profits. Every year spent in testing is a year
that hip implant isn't on the market earning money for the company.
A Pyramid Built on Sand
For
Johnson & Johnson and its subsidiary DePuy, the priority was on
products, not patients. They claimed the ASR XL Acetabular System was
"substantially equivalent" to no less than three other devices already
on the market that had been tested for safety.
Every part of that statement would prove to be inaccurate.
Companies
are allowed to claim that their new product is substantially equivalent
to more than one other product. For example, since they have to show
that they have the same materials and technology as a previously
approved product, a company might show that they used the same materials
as one product and the same technology as another.
For the
ASR XL Acetabular system's
510(k) application, DePuy cited three different previously approved
products saying that the ASR system was "substantially equivalent"-at
least in part-to all three.
By this
argument, you could get a safety approval from the FDA for a flying car
with submarine without ever testing it - after all, it is "substantially
equivalent" - at least in part - to an airplane, a car, and a
submarine. What on earth would be the point in testing it again when the
basic principles have already been proven safe?
The
loophole gets even more absurd: companies are allowed to base their
claims of "substantial equivalence" on products that were approved under
the same 510(k) process.
One of the
devices DuPuy used was approved with one device-that had been approved
through another device-that had been approved through a third
device-that was approved because it was substantially equivalent to a
product grandfathered into the system prior to 1976.
Essentially, DePuy was claiming that their product was substantially equivalent to hip replacements manufactured before the FDA was ever in place
Not
a single hip implant in this chain of FDA was ever subjected to
clinical trials before it was allowed to go to market. Even if it had
been, it seems laughable that a hip implant "substantially equivalent"
to a series of pre-1976 implant could ever make it through the FDA. Has
technology developed so slowly that the best implants on the market are
based on designs from 40 years ago?
Put
it into perspective: the ASR XL Acetabular system was marketed to
younger people who needed a longer-lasting, more durable hip
replacement. That means many of the recipients got a hip implant based on a design older than they were.
Only 10% of applications
submitted under the 510(k) process
are ever returned with a request for clinical trials. That means that
90% of the Class III hip implants available today were never tested in a
clinical setting before being marketed to the public.
It's
a wonder there haven't been more problems with these hip implants. How
many of us would willingly submit to the medical procedures of 40 years
ago?
Testing the DePuy Hip Implant Takes a Backdoor to Profits
Had
thorough clinical testing been done, it would have become clear long
before the product went to market that the ASR XL Acetabular system had a
revision rate of at least 15% and possibly more, not to mention a much
higher rate of metallosis, metal poisoning, bone deterioration, and
tissue damage.
Had DuPuy gone through
the more rigorous PMA process with the FDA, it's likely the ASR system
would never have been sold to the public.
But
then again, that was probably why DePuy didn't go through the more
rigorous process. The 510(k) process and substantial equivalence meant
that DePuy could start making profits off their hip implants much more
quickly. Why risk losing the profits just because the device can't be
proven safe?
While we acknowledge
that companies need to make profits, companies who make medical devices
such hip implants must be driven by consumer safety above all else.
Willingly causing pain and suffering to thousands of people in exchange
for a payoff makes DePuy "substantially equivalent" to a hired thug.
It's a harsh comparison - but one that holds up much better under scrutiny than the ASR XL Acetabular System.
The
ball was equivalent to an approved product; the socket was
equivalent to an entirely different approved
product; and the materials were equivalent
to still a third approved product.