More than 50,000 people with metal-on-metal hip implants in the United Kingdom are being asked to follow up with physicians for additional testing, according to a recently updated safety alert from the country’s Medicines and Healthcare Products Regulatory Agency (MHRA) issued June 29.
The medical device alert follows up on an earlier alert from the regulatory agency from June 2012. The agency initially warned that patients with one of four groups of metal-on-metal hip implants were at risk of developing high levels of blood metal ions.
The update expands the warning and recommendation of additional testing to anyone with a metal-on-metal hip implant, even those who may not be exhibiting any signs of complications.
“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,” Dr. Neil McGuire, MHRA’s clinical director of medical devices, said. “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.”
Roughly 56,000 people in the UK have been implanted with the hip implants and are recommended to undergo X-rays and blood tests to determine whether metal ions have seeped into the blood.
The design of metal-on-metal hip implants is conducive to wear and corrosion, potentially releasing minuscule pieces of metal particles into the soft tissue around the implant. Some may be at risk for developing metallosis and aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL).
Metallosis can result in bone and tissue death, severe pain and implant failure. ALVAL can lead to pseudotumors in the body and may require revision surgery to remove.
Some MoM Hip Implant Complications May Be Asymptomatic
Thousands of patients with these types of implants have already undergone testing after potential complications related to the products have come out over the past few years. The MHRA says that most patients will not experience any complications and that the new guidance is a preventative measure.
“We have updated the current advice to ensure patients with metal on metal hip implants continue to receive appropriate follow up to detect emerging complications should they arise,” McGuire said.
The update from the agency came after experts found that certain complications may not show themselves without testing.
“MHRA’s clinical orthopaedic experts have also observed that soft tissue necrosis may occur in both asymptomatic and symptomatic patients, and believe early detection of these events should give a better revision outcome should this becomes necessary,” the agency wrote in its alert.
The agency drew upon information provided by the British Hip Society on follow-up procedures for patients with metal-on-metal hip implants.
Although there is no threshold on just how much metal can be in the blood, the agency recommends doctors use other factors like implant type, patient health and imaging findings to create a plan around the results.
Alert May Mean Additional MoM Hip Implant Lawsuits
With the expansion of the pool of patients potentially affected by metal-on-metal implants, some expect the number of lawsuits filed against the makers of the artificial hips to increase.
In 2010, the MHRA announced a recall of DePuy ASR metal-on-metal hip implants. DePuy, a subsidiary of Johnson & Johnson, has faced hundreds of lawsuits surrounding its metal hip products.
An investigative report by the Telegraph in 2013 revealed that DePuy continued to market the products for three years while ignoring warnings about possible defects in the design from a leading surgeon.
The UK news outlet also found that the company saw a 10 percent failure rate after two and a half years in June 2007. That failure rate is much higher than comparable hip implant products.
DePuy also faced thousands of lawsuits in the United States surrounding its ASR hip implants. It wasn’t until the company lost trials did it agree to set aside billions of dollars in 2013 to more than 7,000 patients who had surgery to replace their ASR hip.
“The U.S. settlement program provides compensation for eligible patients without the delay and uncertainty of protracted litigation,” the company wrote at the time. “DePuy remains committed to our purpose of advancing innovative treatment options to serve those who need joint replacement surgery.”
Thousands of more suits aimed at all the makers of metal-on-metal implants may be on the horizon.