Serious concerns have been raised by health professionals and experts over the use of metal on metal (MoM) implants when carrying out hip replacements and hip resurfacing to the extent that some experts are calling for them to be banned altogether.
It is estimated that 65,000 people in the UK have undergone a hip replacement using a ‘metal on metal’ implant. Of these, 49,000 are thought to have had what is known as a ‘large head metal on metal implant’ and will require annual checks.
Hip replacements have been carried out for many years and are a common form of surgery where a damaged hip joint is replaced with an artificial one. Traditionally this would have involved using a ceramic or part plastic device but in trying to develop more resilient joints metal on metal implants were introduced. These implants basically feature a joint made of two metal surfaces – a metal ball that replaces the ball found at the top of the thigh bone and a metal cup that acts like the socket found in the pelvis. However, research undertaken by the National Joint Registry of England and Wales, as recently published in the Lancet medical journal, found that metal on metal implants failed far quicker than alternative implants with a 6.2% rate of requiring revision surgery, to remove or replace the implant or part of it, at 5 years in comparison to a 2.3% rate for ceramic implants and 1.7% for part plastic implants.
Unfortunately, it is also apparent that not only do these implants fail faster than the alternatives but there could also be serious health risks to those who have been fitted with them.
As the implant, of which part is made of cobalt and chromium, wears the friction on the metal surfaces can cause metal particles, or ‘debris’ to break off into the body. The debris can cause discomfort and inflammation around the implant which arises from damage caused to the bone and tissue surrounding the hip. Such damage could have a detrimental effect on any later revision surgery. Experts consider that early revision surgery of MoM hip replacements could result in a more successful outcome.
The less obvious concerns relate to the possibility that the debris or implant could leak traces of metal into the bloodstream. Having a high metal count in the bloodstream can cause symptoms people wouldn’t necessarily link to their hip replacement such as headaches, rashes, weakness and symptoms related to the heart, nervous system and thyroid gland. These can be extremely serious and medical attention should be sought immediately by anyone with these symptoms who has undergone a hip replacement or resurface.
These problems have been known by medical professionals and bodies such as the Medicines and Healthcare products Regulatory Agency (MHRA) for a number of years but it is only recently that proper investigation has been carried out and formal guidance given. In 2010, DuPuy a manufacturer of MoM implants actually recalled their ASR and Corail models due to the high number of adverse reactions to the implant.
The MHRA has now issued guidance that anyone who has undergone a MoM hip replacement with a head size in excess of 36mm (large head implant) should be monitored annually for the life of the implant and undergo blood tests to measure the levels of metal particles in their blood whether or not they have any symptoms as described. They have also issued guidance that anyone who has undergone a hip resurfacing procedure or a hip replacement with a head size less than 36mm should be monitored in the same way if they are symptomatic.
Anyone who has suffered pain and discomfort or illness as a result of their ‘metal on metal’ hip replacement or resurface or has required early revision surgery may be able to claim compensation either against the manufacturer of the defective implant or due to any related medical negligence.
Harris Fowler is a specialist solicitor acting on behalf of a number of people affected by problematic MoM hip replacements who can offer expert advice.
Free and professional legal advice is available on 0800 213 214 or visit www.harrisfowler.co.uk
Harris Fowler is a trading name of Harris Fowler Limited and is authorised and regulated by the Solicitors Regulation Authority no. 558271.