Final opinion on Metal-on-Metal joint replacements
Final Opinion on
The safety of Metal-on-Metal joint replacements with a particular focus on hip implants
Stiff joints, aching bones, painful movement – modern medicine has come up with answers to some of the problems of old age. But can some forms of medical interventions like Metal-on-Metal hip and joint replacements actually do more harm than good?
The European Commission has mandated the Scientific Committee on Emerging Newly Identified Health Risks to produce an opinion on “the safety of Metal-on-Metal joint replacements with a particular focus on hip implants”.
A public consultation on the preliminary opinion was open from 13 March to 25 April 2014. Submissions received during the public consultation were carefully examined by the SCENIHR and, when relevant, taken into account in the final opinion.
The text of the comments received and the response provided by the SCENIHR is available here.
Content of the opinion:
The aim of the opinion is to determine the short, medium and long-term local and systemic health effects caused by metal particles, metal ions, and metallo-organic compounds resulting from the implanted medical device. If possible, it should provide indications on limit values for the metals in any form, and advice on the predictive value of metal ions in body fluids, clinical strategies and other aspects needed to ensure the safety of implanted patients.
Finally, the opinion should identify criteria for the safety and safe use of MoM implants used in arthroplasty (joint surgery), paying special attention to design and patient groups. This should inform related medical decisions and identify needs for further research.
SCENIHR concludes that all types of MoM hip arthroplasties release metals in any forms which, once in the body fluids and tissues, may lead to local and/or systemic adverse health effects. MoM implants with large diameters (resurfacing and especially large-head) show the highest incidence of local reactions.
Due to the higher health risk when compared with alternative implants, the application of MoM hip arthroplasty should carefully be considered on a case-by case basis.
The SCENIHR endorses the strategy as outlined in the European Consensus Statement which recommends systematic follow-up for all patients and all implants, including clinical and radiographic investigation at intervals depending on local protocols. In particular, metal ion determination is recommended for large-head MoM total hip arthroplasty on a routine basis and for hip resurfacing arthroplasty patients at least in the first postoperative years.