Researchers are calling for a ban of all-metal artificial hips, citing new evidence that the devices are more prone to fail than traditional hip implants made with plastic or ceramic parts.
Metal-on-metal hip replacement systems are newer devices that were designed to be more durable than older model hip implants, with a metal ball that moves within a metal socket. However, doctors are beginning to find that the devices may actually be performing worse than older hip implants made of other materials like ceramic and plastic.
Artificial hips can last up to 20 years, and failure occurs when the device loosens, dislocates or fractures. With the metal hip implants, however, doctors were finding another symptom – the tissue around the implant was damaged and dying, blackened by bits of metal debris that flaked off when the metal parts of the implant rubbed together. This condition causes pain and inflammation, and can send toxic levels of chromium and cobalt into the bloodstream.
Soaring failure rates led to the worldwide recall of the ASR XL, a metal-on-metal device made by Johnson & Johnson subsidiary DePuy Orthopaedics. The Food and Drug Administration (FDA) shortly thereafter ordered a review of problems associated with all metal-on-metal hip replacement systems.
Meanwhile, in London, more damning evidence was surfacing. A study in the British medical journal The Lancet reported that there is a 6.2 percent chance that patients with all-metal hips will need a replacement within five years – three times greater than what has been seen with older implants. Britain’s medical regulator urged the near-50,000 Britons with metal-on-metal implants to have annual check-ups to monitor for problems, in particular any traces of metal in their bloodstream.
Researchers argued in The Lancet that metal-on-metal artificial hips have “poor implant survival compared with other options and should not be implanted.”