Between 2009 and 2017, approximately 5,000 UK patients received “modular neck” hip replacements—a type of implant that incorporates several metal-on-metal joints. These devices are now believed to be more prone to wear and deterioration, posing a potential health risk for recipients.

Studies have associated these implants with higher rates of failure, fractures, and toxic cobalt ion release due to the breakdown of the metal joints. Released cobalt particles can harm tissue around the implant and potentially spread throughout the body, leading to an array of medical complications. Despite these risks, around 100,000 surgeries involving cobalt-based implants are still conducted each year.

Medical providers must warn patients about potential risks and conduct regular monitoring of chromium and cobalt levels in patients’ blood. In 2017, the UK’s Medical & Healthcare Products Regulatory Agency (MHRA) issued guidelines suggesting that blood cobalt and chromium levels above seven parts per billion (ppb) may indicate implant wear or corrosion, which could necessitate further testing and close follow-up.

Cobalt toxicity has been linked to a variety of debilitating symptoms, including heart and kidney dysfunction, hearing and vision impairment, memory loss, chronic fatigue, depression, nerve damage, nausea, vomiting, chronic pain, cognitive decline, thyroid dysfunction, and muscle weakness. These symptoms can profoundly affect patients’ lives and may require extensive medical care.

The law firm Leigh Day has taken a leading role in representing individuals who have experienced adverse effects from metal-on-metal hip implants. This includes those affected by DePuy ASR hip resurfacing and total hip replacement implants, with Leigh Day representing more than 600 clients who suffered serious reactions to metal debris. Angela Bruno, a senior associate solicitor in Leigh Day’s product liability team, voiced concern over similar risks associated with modular neck implants. Bruno noted, “Studies have shown that the multiple joints in these implants create more potential for wear, leading to metal ions entering the body and causing conditions such as cobalt poisoning.”