Most British patients with all metal artificial hips should be followed up throughout their lifetime with regular magnetic resonance imaging (MRI) scans to check for any potential problems, Britain's medical regulator said on Tuesday.
The Medicines and Healthcare Products Regulatory Agency (MHRA) issued the new clinical guidelines to doctors about the artificial hips after some patients reported problems that needed more surgery or caused other health problems.
The regulator said around 49,000 patients out of 65,000 with all-metal hips were in a high risk category.
The move will fuel controversy about the regulation of medical devices in Europe in the wake of a scandal over France's Poly Implant Prothese (PIP) breast implants. Critics argue European oversight is too lax to spot substandard products.
Metal-on-metal hips were developed to be more durable than traditional implants, which combine a metal or ceramic ball with a plastic socket.
But patients receiving some all-metal hips turned out to be more likely to need repeat surgery than those who got implants made of other materials. They also produce debris that can release chromium and cobalt ions into the blood, causing health problems.
(Reporting by Ben Hirschler, writing by Kate Kelland, editing by David Jones)