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 (large-head) show the highest incidence of local reactions; moreover, the subgroup of large-head MoM in total hip arthroplasty should be avoided on the basis of their high failure risk.
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.