What is the problem with Metal on Metal Hip (MoM) Implants?
On Tuesday 28th February, 2012 the Medicines and Healthcare products Regulatory Agency (MHRA) issued an Updated Device Alert relating to all MoM hip replacements. The MHRA advised surgeons that patients who had this type of hip medical device should be monitored annually for the life time of the patient. This advice is based on recently updated evidence that patients with MoM hip replacements with head diameter of 36 millimetres or more need to be monitored every year. The Irish Medicines Board (IMB) has written to all Orthopaedic Surgeons and those involved in the management of patients, of joint hip replacements advising of the MHRA Medical Device Alert.
Conclusions from the most recently published research are that the DePuy MoM hip device problems may extend to other MoM hip implant manufactures. It appears that these problems are taking longer to manifest themselves. The Lancet is one of the world’s leading medical journals and in a recent article “Failure rates of stemmed MoM hip replacements”, the authors, renowned experts in their field; recommended that MoM bearing surfaces are not used in stemmed hip replacements.
Problems with MoM hip implants first emerged in July 2008 when Zimmer temporarily suspended marketing and distribution of the Durom® Acetabular Component (Durom Cup) in the U.S. This was as a consequence of very high failure rates. Zimmer continued to market the Durom Cup outside the U.S. particularly in Europe. In August 2010 DePuy had to voluntarily recall its ASR MoM hip implant for resurfacing and total hip replacement because of increasingly high failure rates. The ASR total hip implant has now been shown to have a failure rate of up to 50% within six years. At the 2011 British Orthopaedic Association’s annual conference, concern was expressed that large diameter MoM devices from medical device manufacturers were also showing higher than expected failure rates, particularly in women. The device components are constructed from a cobalt-chromium alloy. There is increasing complaints of “metal poisoning” associated with MoM hip implants. This is a due to the MoM implant design which greatly accelerates wear of the metal joint. As debris is generated from wear and tear, high concentrations of chromium and cobalt ions can cause extensive tissue and bone damage and the leeching of ions into the blood stream.
Surgeons in the UK have called for a ban on MoM hip implants because of their high failure rate. There are over 12,000 MoM hip implant patients in the Republic of Ireland.
How do I know if I have a MoM Hip Implant?
The hospital where you had your surgery performed will always have a record of your operation and what implants were used. You can contact the hospital directly or you can contact your GP and they can help put you back in contact with your consultant orthopaedic surgeon.
How often should I have my MoM Hip Implant checked?
The most recent advice from the UK Medicines and Healthcare products Regulatory Agency (MHRA) to surgeons is that patients with a particular type of MoMhip replacement should be monitored annually for the life of the hip replacement.
Which Mom Hip Implants are used in Ireland and the UK?
Here are the most common brands of hip implant device with the name of the manufacturer –
• ADEPT Hip Resurfacing Manufactured by Finsbury Orthopaedics (DePuy).
• ASR Hip Resurfacing Manufactured by DePuy.
• Birmingham Hip Resurfacing Manufactured by Smith & Nephew.
• Conserve Plus Total Hip Resurfacing System Wright Medical.
• Cormet 2000 Hip Resurfacing Manufactured by Corin.
• Durom Hip Resurfacing Manufactured by Zimmer.
• ReCap Hip Resurfacing Manufactured by Biomet.
The specialist medical device negligence team at Malcomson Law is led by Raymond Bradley, Managing Partner. Raymond has extensive experience of taking medical negligence and health related cases in the Irish High Court, and in representing victims of health scandals at public inquiries and compensation tribunals.
Over a period of 20 years Malcomson Law have represented numerous claimants in various class claim actions, both in Ireland and in other jurisdictions. These actions related to defective products including blood products, pharmaceutical products and medical devices. In that regard, we are very familiar with the principles that are required for the purpose of advancing such defective product litigation.
If you have a MoM hip implant please phone us at 01 87 444 22