U. S. Food and Drug Administration (FDA) have approved, on 14th June, 2011, a ceramic-on-metal hip replacement system and the treatment has been particularly sanctioned for people facing osteoarthritis. The decision has been based upon strong research supporting the superiority of the ceramic-on-metal system over other popular methods like metal-on-metal, and ceramic-on-ceramic replacements. This marks a promise in hip replacements as discussed below.
This decision is based upon a research conducted over the past two years. Since recent studies recommend the use of ceramic-on-metal, it is finally approved after careful considerations. Research studies include clinical trials and some are laboratory based. There are several ways in which the ceramic-on-metal system is better than the existing techniques. Still, post market research is in progress even after the approval for giving a deeper insight into the treatment.
Fisher and colleagues did a six-month follow-up and compared the ceramic-on-metal system with metal-on-metal, polythene-on-metal, and ceramic-on-ceramic systems. They concluded that ceramic-on-metal articulations resulted in 50% reduction in metal ions, primarily cobalt and chromium as compared to metal-on-metal replacements. Moreover, they discovered that ceramic-on-metal replacements provide a greater flexibility of design and also have a lower risk of fractures than ceramic-on-ceramic systems. Other studies found lower concentration of molybdenum ions in COM systems as compared on MOM.
Furthermore, British researchers suggested that the ceramic-on-metal hip replacement resulted in much lesser friction as compared to the popular, metal-on-metal system. These findings have been replicated several times: Ceramic-on-metal systems have significantly superior lubrication that prevents breakage and wear of the surrounding bones.
Wear and Tear
The ceramic-on-metal systems have significantly low wear rate (0.1mm3 per million cycles) than metal-on-metal replacements which have a wear rate of 1mm3. Also, the Ceramic-on-Metal systems have also been found to show no bedding wear that is commonly observed in metal-on-metal articulations. Some studies report 10 fold less wear and tear than metal-on-metal hearings, yet others assert that the difference is 100 folds.
A post-approval study has been advised in order to analyze the long term effects of the artificial hip replacement generally and increased amount of metal ions particularly. Warsaw, Ind. based company, DePuy Orthropaedics, are the manufacturers of the new device, and they are advised by FDA to carry out further research examining any adverse effect of the system. Like most innovations, this one needs follow up observations. Still, the ceramic-on-metal bearings mark a promise as the research to date only supports this method over others.