Medical device regulators in the United Kingdom (UK) are urging more than 50,000 metal-on-metal hip replacement recipients to undergo x-rays and blood testing, even if they have not experienced pain, swelling or other issues that could indicate a problem with their implants.
Metal-on-metal hips consist of a ball, stem and shell, all made from cobalt-chromium-molybdenum alloys. Introduced in the 1990s, the devices were marketed as a more durable option for younger, active patients. In the U.S., all-metal hips were cleared via the Food & Drug Administration’s (FDA) 510(k) program, which allows a device to come to market without human clinical trials if it is “substantially equivalent” in design to a previously approved product.
The FDA launched a safety review of metal-on-metal hip replacements in February 2011, amid concerns that many patients were experiencing premature failure of their implants. In a January 2013 Safety Communication, the agency confirmed that exposure to metal ions released from an all-metal hip 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. Patient with metal-on-metal hips were urged to seek medical attention if they experienced any issues with their implants, while doctors were advised to consider metal ion blood testing and imaging for symptomatic patients.
In 2016, the FDA finalized new regulations that, among other things, banned medical device makers from utilizing the 510(k) program to bring metal-on-metal hips to market.
Though they’ve been largely phased out, around 56,000 people in the UK still have metal-on-metal hips. The MHRA had previously recommended screening for all-metal hip patients considered high risk. However, the agency’s latest alert suggests that any individual with a metal-on-metal device should undergo annual testing, “as soft tissue necrosis may occur in both asymptomatic and symptomatic patients.”
“Although the majority of patients with these metal on metal devices have well-functioning hips, it is known some may develop soft tissue reactions related to their implant,” MHRA’s Clinical Director of Medical Devices said in a press release dated June 29th. “The clinical advice we have received indicates patients will likely have the best outcomes if these problems are detected early, monitored and treated if necessary.”
In recent years, thousands of hip replacement lawsuits have been filed in U.S. courts on behalf of individuals who allegedly experienced premature device failure and other debilitating complications due to metal-on-metal implants. In November 2013, DePuy Orthopaedics agreed to pay $2.5 billion to resolve claims involving its ASR line of all-metal hips, which were recalled in August 2010. However, thousands of lawsuits involving a metal-on-metal version of the DePuy Pinnacle hip replacement 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.