Patients with a common type of metal hip implant should have annual health checks for as long as they have the implant, according to the UK body for regulating medical devices. The all-metal devices have been found to wear down at an accelerated rate in some patients, potentially causing damage and deterioration in the bone and tissue around the hip. There are also concerns that they could leak traces of metal into the bloodstream, which the annual medical checks will monitor.
Hours before critical coverage from the British Medical Journal and the BBC, the Medicines and Healthcare products Regulatory Agency (MHRA) issued new guidelines on larger forms of ‘metal-on-metal’ (MoM) hip implants. Advice on smaller metal devices or those featuring a plastic or ceramic head has not changed. Previously, guidelines suggested larger MoM implants should only be checked annually for five years after surgery. The agency now says the annual check-ups should be continued for the life of the implant. Check-ups, they say, are a precautionary measure to reduce the “small risk” of complications and the need for further surgery.
Together with the recent controversy over PIP breast implants, the news has caused the media and patient groups to call for tighter regulation of medical devices, perhaps bringing the approval process into line with that of medicines. Before they can be approved for wider use drugs must undergo several years of laboratory, animal and human testing .
What types of implants are involved?
There are numerous designs and materials used to make hip implants. In recent days the MHRA has issued major updates to its advice on a type of metal-on-metal (MoM) hip replacement. As the name implies, MoM implants feature a joint made of two metal surfaces – a metal ‘ball’ that replaces the ball found at the top of the thigh bone (femur) and a metal ‘cup’ that acts like the socket found in the pelvis.