Medical device regulators in the United Kingdom (UK) have opened a new investigation into metal-on-metal hip replacements, amid concerns that chromium and cobalt shed from the implants could be putting thousands of people at risk for dementia and heart problems.
Metal-on-metal hip implants, which include DePuy Orthopaedics recalled ASR hip replacements, as well as a version of the DePuy Pinnacle hip that utilizes the Ultamet liner, have been the subject of controversy for over a decade. While they were marketed as a durable option for younger, more active patients, data have shown that metal ions released from the devices increase the risk for adverse local tissue reactions and other problems that can result in premature failure of the implant.
Last year, an Australian study published in the journal Acta Orthopaedics indicated that men fitted with the DePuy ASR XL hip replacement system were more likely to be hospitalized for heart failure compared to those who had received a metal-on-polyethylene hip. Research published in BMC Psychiatry earlier this year involving 10 all-metal hip patients reported that 9 had depression, while 7 exhibited problems with memory and cognition.
According to The Times, the UK’s Medicines & Healthcare Products Regulatory Agency has established an expert group to determine whether or not these studies point to a wider problem that could affect tens-of-thousands of people who still have metal-on-metal hips. Just last month, the agency urged such individuals to undergo annual blood-tests and imaging screens, even if they weren’t experiencing any symptoms that could indicate a problem with their implant.
The U.S. Food & Drug Administration (FDA) launched a safety review of metal-on-metal hip replacements in February 2011. In January 2013, the agency confirmed that exposure to metal ions released from the devices could cause an adverse local tissue reaction in the area around the joint. The tiny metal particles could also enter the bloodstream and travel to other parts of the body, potentially resulting in additional symptoms or illnesses. All-metal hip patients were advised to talk to their doctor if they experienced any issues with their implants, while physicians were urged to consider metal ion blood testing and imaging for symptomatic patients.
Thousands of people in the U.S. have since filed hip replacement lawsuits over complications allegedly associated with metal-on-metal implants. In November 2013, DePuy Orthopaedics announced a $2.5 billion hip replacement settlement to resolve clams stemming from its August 2010 ASR recall. However, thousands of lawsuits involving the all-metal version of the DePuy Pinnacle system remain to be litigated.
In February 2014, Biomet Inc. agreed to a $56 million settlement that resolved many of the hip replacement lawsuits involving its M2a line of metal-on-metal hips. And last November, Wright Medical agreed to pay $240 million to settle nearly 1,300 cases involving its all-metal Conserve, Dynasty and Lineage hip replacements.