DePuy Hip Measuring Error Results in Wrongly-Fitted Implants: Report

Thousands of DePuy metal-on-metal hip implants sold in the U.K. may not fit patients correctly, due to measuring problems during the manufacturing process. 

According to a report by the Telegragh, documents from the medical device manufacturer indicate that a problem with a metal liner used in the Depuy Pinnacle and ASR hip replacement systems may have led to thousands of the poorly fitting implants before the problem was corrected.

The report indicates that DePuy knew about the hip measuring error at its Leeds manufacturing facility as early as 2008. A company spokesperson told the paper that the company investigated the issue, removed the equipment, and concluded there were no safety issues.

While the initial documents were linked to the Ultamet, a liner used in the Pinnacle, another document indicated that manufacturing problems also affected the DePuy ASR series of implants, which were subsequently recalled worldwide in 2010, due to a high rate of failures. It is unclear when DePuy corrected the problem.

The DePuy ASR design features a metal femoral head that rotates within a metal acetabular cup, resulting in the release of metallic debris as the parts rub against each other during normal daily activities. This debris may cause individuals with a DePuy ASR hip to suffer metal blood poisoning, known has hip metallosis, with can lead to the loosening and ultimate failure of the artificial hip.

While original estimates suggested that about one out of every eight recalled DePuy ASR hips may fail within five years, subsequent data suggests that the failure rate may be substantially higher the longer the implants remain in place.

More than 12,000 DePuy ASR hip lawsuits were filed in the U.S. before a multi-billion dollar settlement reached in 2013 by the manufacturer.

The manufacturer also faces thousands of DePuy Pinnacle hip implant lawsuits in the United States, which are centralized in the Northern District of Texas before U.S. District Judge Ed Kinkeade to reduce duplicative discovery into common issues in the cases, avoid conflicting rulings from different courts and to serve the convenience of the parties, witnesses and the courts.

As a small group of cases are being prepared for bellwether trials in the MDL, which are designed to help the parties gauge how juries may respond to certain evidence and testimony that is likely to be repeated throughout the litigation, new cases continue to be filed on behalf of people who have experienced problems with the metal-on-metal implant.