There is no evidence that metal-on-metal hip implants increase the risk of cancer although longer-term studies are needed, experts have said.

A new analysis of almost 41,000 patients found no link between the controversial implants and the disease in the seven years following surgery.

Cancer is just one of the fears linked to the implants, which have prompted close monitoring of all patients following high failure rates.

Tiny metal ions made up of cobalt and chromium are thought to break off from the implants and leak into the blood, with fears this leads to muscle and bone damage and neurological issues.

The data, based on the National Joint Registry of England and Wales, follows advice issued on Tuesday that said surgeons should stop using one particular type of total hip implant.

Evidence shows the implant has a revision rate of 10.7% just four years after initial surgery which is "unacceptably high", the Medicines and Healthcare products Regulatory Agency said.

The research, published online in the British Medical Journal, is based on 40,576 patients with metal-on-metal hip implants and 248,995 who have other types, linked to hospital data.

The experts, from the Universities of Bristol and Exeter, found no evidence of an increased risk of any type of cancer in people with implants compared with the general population.

However, they said "as some cancers have a long latency period it is important that we study the longer term outcomes and continue to investigate the effects of exposure to orthopaedic metals".

Last month experts writing in The Lancet medical journal called for all metal-on-metal implants to be banned due to evidence of high revision rates.

http://uk.news.yahoo.com/cancer-reassurance-over-hip-ops-225939499.html