Failures of Zimmer Hip and Knee Implants Raises Questions from Senator

A senior U.S. senator is asking questions about reported problems with Zimmer hip and knee replacement systems and is asking the medical device manufacturer whether there are problems with other products that have not yet been reported. 

Senator Charles E. Grassley wrote a letter to Zimmer CEO and President David C. Dvorak on July 29, requesting additional information on what the company was doing to respond to complaints about failures in the Zimmer Durom Cup hip replacement system and Zimmer NexGen knee replacement system. Grassley is the ranking minority member of the Senate Finance Committee, which has jurisdiction over Medicare and Medicaid.

Grassley cited recent media stories about concerns raised by former Zimmer consultants who disputed company claims that the problems were not with the implants themselves, but in how doctors were surgically implanting them.

In his letter, Grassley asks the company for details on its process to respond to safety concerns. He also asked whether there were more consultants who had raised concerns about Zimmer implants and requested that the company provide detailed information on the consultant, implants and the problems reported, and whether the reports ever led to a Zimmer recall.

The Zimmer Durom Cup artificial hip was first introduced in the United States in 2006, as a more advanced form of a hip resurfacing system. The device is designed out of a single piece of material and is supposed to avoid problems associated with traditional hip replacement components, such as instability, limited range of motion and wear of the bearing.

Shortly after Zimmer introduced the Durom Cup in the United States, concerns emerged about a high number of hip replacement failures involving the hip implant, where the component loosened and required revision surgery. A temporary Zimmer Durom Cup recall was issued in July 2008, so that revisions could be made to the product’s warnings and instructions to ensure that doctors were properly trained on the surgical techniques needed to implant the artificial hip correctly.

Approximately 12,000 individuals had the Zimmer Durom Cup system implanted in their hip between 2006 and 2008. While Zimmer’s own estimates in 2008 suggested that some doctors have experienced failure rates as high as 5.7%, more recent claims made in Zimmer Durom Cup lawsuits suggest that the artificial hip failure rate is between 20% and 30%.

In June, the U.S. Judicial Panel on Multidistrict Litigation decided to consolidate and centralize all lawsuits over the Zimmer hip replacement in the U.S. District Court for the District of New Jersey as part of a multidistrict litigation (MDL) for pretrial litigation. At that time, 45 cases had been filed in federal courts throughout the United States. However, as additional cases are filed by Zimmer Durom Cup lawyers in federal court, they will be transferred to New Jersey for coordinated handling.

Problems with Zimmer NextGen knee replacement systems have sparked similar controversy. In March, a group of orthopedic surgeons released a report highlighting the risk of failures with the Zimmer NextGen artificial knee, which has also been found to have a high rate of failures and revisions. The surgeons looked at the two year results of 108 knee replacement surgeries involving the Zimmer NexGen CR-Flex Porous Femoral knee replacement system, which uses a component that attaches to the bottom of the thigh bone without traditional cement to glue it in place.

They found that nearly 9% required revision surgery and that 36% showed signs of the replacement knee loosening, concluding that the Zimmer NexGen knee problems were linked to the design of the implant, and were not related to the surgeon, the surgical approach or the type of patient receiving the knee implant. Zimmer NexGen knee replacement lawyers are also investigating potential lawsuits on behalf of individuals who have experienced problems or required revision of their artificial knee.