Knee Replacement Device Warnings
knee replacement problems: including Zimmer NexGen CR Flex and Smith & Nephew Oxinium Genesis II and Oxinium Profix II
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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 the report: 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 Australian data 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 said they 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.

DePuy Preservation knee replacement implants show high failure rate

Studies of data from England and Wales have shown an unusually high failure rate for DePuy Preservation knee replacement implants.

The DePuy knee replacement implants caused a range of problems for patients, including:

  • loosening,
  • pain,
  • wear of the polyethylene component and
  • early periprosthetic fracture.

A regulatory report released in England states:

Detailed analysis of data from the England and Wales National Joint Registry (NJR) has shown that the mobile bearing variant of the Preservation unicompartmental knee system has a higher than expected early revision rate compared to other unicompartmental knee systems used in England and Wales. Of 264 DePuy Preservation unicompartmental mobile bearing knee implants recorded on the NJR database between 01/04/2003 and 18/11/2008, 34 (12.9%) of these have been revised (as of July 2009).

The exact cause for the high revision rate is not known but is likely to be multifactorial. Failure modes reported to date include: loosening, pain, wear of the polyethylene component and early periprosthetic fracture.

In light of this and after continuing analysis by the manufacturer, DePuy has now ceased actively promoting the mobile bearing variant of this knee system in the UK and has confirmed to the MHRA that it will be discontinued throughout Europe from August 2009.

For more information about these issues, contact the lawyers of Aylstock, Witkin, Kreis & Overholtz.

Smith & Nephew recall of Journey Uni Tibial Baseplate

Smith & Nephew has recalled the Journey Uni Tibial Baseplate knee device due to a defect causing broken baseplates in patients.

The product name is "Journey Uni Tibial Baseplate," (Right Medial / Left Lateral).

As noted in the FDA bulletin on the recall, the firm has received complaints of the base plates breaking in situ. If a breakage occurs, the broken baseplate must be revised and/or changed. If left unrevised a broken base could lead to instability and premature wear of the construct.

Smith and Nephew Journey Uni Tibial Baseplate recall details

For more information about the Smith & Nephew recalls, visit or contact the lawyers of Aylstock, Witkin, Kreis & Overholtz.

Smith & Nephew recall defective knee replacement systems

The London-based medical device manufacturer Smith & Nephew has announced a recall of two of their knee replacement products. Smith and Nephew stopped sales of the products and alerted U.S. authorities of the problems associated with the knee implants in August, 2003.

Smith and Nephew announced a voluntary recall of the cementless versions of their Oxinium Genesis II and Oxinium Profix II knee replacement systems. The London-based company reported that corrective follow-up surgery was needed for about 30 of the 3,000 patients fitted with the products in the United States, according to information first published in the British publication The Guardian.

Knee implant products make up approximately $370 million of the global corporation's annual revenues of $2.2 billion (based on Feb. 8, 2003, conversion rates from U.K. pounds). The specific knee implant products recalled are believed to account for approximately $3.7 million of sales revenue.

Most recalls of defective medical devices in the United States are voluntary actions taken by the manufacturer, although the U.S. Food and Drug Administration can force a recall if the manufacturer declines to remove a defective product from the market voluntarily.

For more information about the Smith & Nephew recalls, visit or contact the lawyers of Aylstock, Witkin, Kreis & Overholtz.