In spite of warnings, Zimmer NexGen CR Flex knee replacement implants still on market
Zimmer Holdings, manufacturer of NexGen knee replacements, continues
to market the devices, in spite of a March 2010 report revealing alarmingly
high failure rates in the CR Flex.
Two experienced orthopedic surgeons prepared the NexGen report, finding
that the Zimmer NexGen CR Flex femoral component came loose in 36% of cases reviewed --
and 9.3% of patients had to undergo revision surgery to fix the painful problem.
Both failure rates are far above the normal range for such knee implant devices,
according to doctors who have reviewed the data.
"This component is still commercially available but should not be used
for any patient," the doctors said, in the report.
The doctors presented the report March 11, 2010 at the annual meeting of
the American Academy of Orthopedic Surgeons (AAOS) in New Orleans. The report,
entitled "The High Failure Rate of a High-Flex Total Knee Arthroplasty Design,"
points to statistics from 146 total-knee arthroplast (TKA) surgeries.
Four authors signed onto
Hany Bedair, M.D.; Megan Tormey; Craig J Della Valle, M.D.; and Richard A Berger, M.D.
One of the authors, Dr. Berger, had previously tried to convince Zimmer Holdings
to fix the problem or remove the product from the marketplace. Dr. Berger felt
compelled to criticize the product even though he had made $8 million working for
Zimmer, designing surgical tools and devices and training doctors. The company
responded to the warnings by punishing the doctor for speaking out.
(See New York Times:
"Surgeon vs. Knee Maker: Who’s Rejecting Whom?")
Because the company refused to act on his warnings, Dr. Berger went public
with the information, presenting the "High Failure Rate" report at the annual
AAOS meeting. Again, Zimmer refused to heed the warning. Instead, the company
released a statement pointing to data from Australia and claiming the product
is perfectly safe. However, that same
shows that the
Zimmer NexGen LPS has the second highest revision rate of the 20
knee replacement devices listed -- nearly 60% higher than the average.
Although Zimmer ignored Dr. Berger’s warnings,
United States Senator Charles E. Grassley (R, Iowa) did not.
Senator Grassley sent a
harsh letter to Zimmer CEO/President David Dvorak, demanding answers to questions
about the safety of the knee implant devices.
(See Sen. Grassley's
letter to Zimmer)
Dvorak and his company have not released details of the conversation with
Sen. Grassley following the senator’s letter. The company has only
answered questions about the company’s complaint handling processes.
Sen. Grassley’s letter pointed out that, because of an
earlier agreement with
federal prosecutors, Zimmer Holdings was required to post detailed information
about financial relationships with healthcare providers. Federal prosecutors in
New Jersey had filed charges against Zimmer Holdings, alleging conspiracy to
commit violations of the Federal Anti-Kickback Statute, but reached an agreement
with the company, requiring detailed public disclosures.