Anatomy of a Public Divorce

Did Zimmer Holdings cancel a consulting agreement with one of its physician/consultants because he reported problems with the company's NexGen CR-Flex knee replacement implant? Is there a problem with the knee and how does the orthopedic community make such a determination?

Those questions arose from a June 20 article in The New York Times titled, “Surgeon vs. Knee Maker: Who’s Rejecting Whom?”

“Ugly Divorce”

The article described a very public "ugly divorce" between knee surgeon Richard Berger, M.D. and Zimmer. Berger, according to the piece, was paid over $8 million in the last decade as a consultant to the company. Then, according to Berger, after complaining to Zimmer that the NexGen was failing prematurely, the company discontinued his consulting agreement.

Berger told The Times that he made Zimmer "tens of millions of dollars, " and wondered whether or not Zimmer's decision to discontinue his consulting contract with the company last year was mere "coincidence."

Zimmer Responds

We contacted the company and asked if Berger's contract had been discontinued because of his criticism. Zimmer responded to our questions the day after the Times article appeared..

The company provided us with a statement that said Zimmer hadn't taken any action to end its consulting relationship with Berger.

"In 2008, Zimmer entered into royalty buy-out agreements with most of its then-current royalty-bearing surgeons in the U.S., including Dr. Berger. As previously disclosed on Zimmer’s website, Dr. Berger received $5.7 million from Zimmer, as late as 2008, as part of a payment for acquisition of intellectual property rights in place of future royalty payments.

“Since 2006, Dr. Berger has been invited to participate in new product development teams and remains a consultant on Zimmer’s minimally-invasive conservative hip stem project. To date, Dr. Berger remains a valued customer of Zimmer."

Berger told The Times a different tale, stating that he was talking with another device maker about consulting and trying out other products.

Zimmer Post-Prosecution

After the Deferred Prosecution Agreement between Zimmer (and other hip and knee makers) and the U.S. Justice Department, Zimmer CEO, and attorney, Dave Dvorak revamped the company's consulting relationships agreement with consulting physicians. It was widely reported by Wall Street analysts that Dvorak's aggressive restructuring of the company's compliance program would cost the company market share. Dvorak and the company gambled that the future regulatory and compliance environment would require a massive restructuring of the surgeon/industry relationship. He argued that the company that gets this right first would be able to avoid the disruptions that federal investigations and prosecutions could later cause. He also hoped that getting a headstart developing the best compliance program would give Zimmer an edge over the competition.

Knee Problem?

What about Berger's reported problems with the knee?

Zimmer's NexGen Femoral Component

The NexGen CR-Flex Porous Femoral Component has a strong track record of clinical success and more than 150, 000 of the devices have been sold since 2003.

The company noted that Berger first reported revisions of the NexGen CR-Flex Porous Femoral Component to members of Zimmer’s Marketing and Development teams in October 2006.

"Following these reports, Medical Device Reports (MDRs) were filed with the FDA and an internal investigation into the system was conducted. The results of this investigation were shared with Dr. Berger, though Dr. Berger expressed disagreement with the conclusions of Zimmer’s analysis. At the Harvard Hip and Knee Meeting in October 2009, Dr. Berger reported on additional revisions of the NexGen CR-Flex Porous Femoral Component. Following this meeting, Zimmer contacted Dr. Berger to obtain the necessary information to file MDRs with the FDA. Dr. Berger discontinued use of the NexGen CR-Flex Porous Femoral Component by November 2006."

The NexGen femoral component, according to the company, was the subject of a study of 108 patients (“The High Failure Rate of a High-Flex Total Knee Arthroplasty Design”) by Drs. Berger and Della Valle of Rush University Medical Center. According to the published abstract, "Drs. Berger and Della Valle revised 9 (8.3%) patients for femoral loosening and pain. The study also reported that 39 (36%) patients showed evidence of radiographic loosening and that '[l]oosening and revision were not related to surgeon, approach or patient type.'"

Berger said there is a problem with the knee, but Zimmer says because there is no evidence in the registry or its investigation to point to product failure, the reported problems are likely due to physician surgical technique.

There was a similar situation with the company’s Durom hip in 2008. In that situation, the company also pointed to the implant technique of the surgeon. In this case, a temporary recall of the device was issued so that changes could be made to the warnings and instructions provided with the product.

Australian Registry Data

According to the 2009 Australian National Joint Replacement Registry report, Zimmer says its NexGen cementless total knee arthroplasty (TKA) components recorded the lowest revision rate (reported as revisions per 100 observed component years) of all major cementless TKA systems utilized in the market (0.5 revisions per 100 observed component years). Of the 7, 100 implantations using the NexGen CR Porous or NexGen CR-Flex Porous systems since 2004, revisions were reported for 120 patients, representing a revision rate of 1.7%, inclusive of all components and reasons for revision.

"The performance of the NexGen CR-Flex Porous Femoral component in the Australian National Joint Registry and in Zimmer’s post-market surveillance activities demonstrates that it is a safe and effective product when used as indicated in the surgical technique. More than 150, 000 NexGen CR and NexGen CR-Flex Porous Femoral components have been sold since 2003. Sales of the NexGen CR-Flex Porous component represented approximately 2% of the company’s knee revenues in 2009, " added the company.

Need For U.S. Registry

So who's right?

“There is no way of knowing who is right because we don’t have the data, ” Kevin J. Bozic, M.D., a professor of orthopedic surgery at the University of California, San Francisco, told The Times.

Zimmer has supported the development of a national joint registry in the U.S. Such a registry would provide the data referred to by Bozic.

A joint registry monitors the artificial joint throughout a recipient’s lifetime in a database with information about the patient, surgeon and facility where the procedure took place. The data collected helps doctors to quickly identify poorly performing products and match patient procedures and devices to optimize outcomes.

The American Academy of Orthopaedic Surgeons (AAOS) is actively engaged in creating a U.S. joint registry and incorporated the American Joint Replacement Registry in June 2009.

After all, if there is no registry in the U.S., how do companies like Zimmer know how their products are doing?

Zimmer Post-Market Surveillance

Zimmer’s statement to OTW noted that the company conducts proactive post-market surveillance on all of its products, and investigates all reported complaints related to the performance of its implants. Each reported complaint is addressed through an evaluation process that involves members of Zimmer’s Quality and Regulatory Compliance teams. This process is a component of Zimmer’s Quality System required by the FDA. 

All complaints are immediately reviewed to determine the potential for MDR under 21CFR803 to the FDA. All MDR reportable events are reported to the FDA, and are tracked to determine if there are adverse trends that warrant further investigation or a corrective field action.

Zimmer said that if a revision is determined to be an isolated event, the company continues to monitor the performance of the product. If a trend in revisions is noted, the company commences an investigation. 

Here's how the investigation process works:

• Review of all aspects of the design, manufacture and implantation (including the surgical technique and post-surgical care protocols) of a device.
• Analysis of radiographs and explants, when available, and all clinical data available, including published clinical studies, Zimmer clinical data and National Joint Registry data.
• Depending on the results of these steps, field action may be started to address any patient safety issues. A field action can range from a recall of the product to a recall and update of the surgical technique. 

A Referee

While the salacious details of a public divorce and details of big dollar physician/industry relationships caught the public attention in this case, the real issue here is that the demand for a national joint registry is building. Until then, these “he said, they said, ” situations will continue.