Poisoning fears over metal hip replacements are investigated

The Medicines and Healthcare products Regulatory Agency (MHRA) said it had taken “prompt action” over the concerns about “metal-on-metal” (MoM) replacements, which are now believed to be more dangerous than previously thought.

Friction between the implants’ ball and cup can cause tiny metal filings to break off and potentially seep into the blood, as well as causing a soft tissue reaction, destroying muscle and bone.

It is also feared that the artificial joints can cause “systemic toxicity” in the body.

More than 30,000 British patients are believed to have had them fitted, and a personal injury law firm revealed it had taken instructions from hundreds of potential victims.

The MHRA has begun drawing up safety advice for patients who may be affected.

A spokesman for the Government agency said: “On the evidence currently available, the majority of patients implanted with metal-on-metal hip replacements are at low risk of developing any serious problems.

“We are continuing to closely monitor all evidence. This needs more analysis before any conclusions can be drawn and further advice given.

“We have already taken prompt action to investigate safety concerns and have provided advice on patient management to relevant healthcare professionals.”

The agency, which is responsible for ensuring that medicines and medical devices work, issued a safety alert about the implants in April 2010. The warning followed reports that some patients had suffered soft tissue reactions “to the wear debris associated with MoM articulations”.

It recommended that patients fitted with the implants should undergo annual check-ups for five years following surgery.

Those experiencing pain should be tested for cobalt and chromium levels in their blood and should have an MRI or ultrasound scan to check for soft tissue reactions, the agency added.

Bozena Michalowska, of law firm Leigh Day & Co, which is representing more than 300 victims of the MoM implants, said: “We have known for some time the perils of these implants and their widespread use has meant we are now seeing hundreds of cases from people who have had these implants.

“The MHRA needs to be fully able to assess these products before they are implanted and not just pick up the pieces many years after the damage has been done.”

In September 2010, DePuy International, a subsidiary of Johnson & Johnson, announced it was urgently recalling two types of its ASR metal hip replacement implants.

It came after data from the National Joint Registry of England and Wales found “failure rates” of 13 per cent for the ASR XL Acetabular system and 12 per cent for the ASR Hip Resurfacing System. However, a report by the British Hip Society seen by a Sunday newspaper suggests failure rates of the Acetabular system could actually be as high as 50 per cent six years after surgery.

Following the recall the MHRA advised orthopaedic surgeons to contact and monitor all patients given the implants.

More than 10,000 Britons who have had metal hip replacements were fitted with the devices made by DePuy, according to reports.

Details of the MoM investigation emerged as Jean-Claude Mas, the founder of the company PIP, learned he faced charges of “involuntary injury” in France after 40,000 British women were given breast implants filled with non-medical grade silicone.