There has been concern about 'metal-on-metal' hip replacements – where a metal ball fits into a metal cup implanted into the pelvis – with problems reportedly occurring when friction between the ball and cup causes tiny metal filings to break off. These filings can seep into the bloodstream and cause inflammation, which can destroy muscle and bone.
The first metal-on-metal devices were introduced in the 1990s, when they were seen as offering better mobility than other materials, but most were withdrawn from the market in 2010.
Now SMART-HIP, a research project led by Cambridge coating specialist Tecvac Ltd and leading UK hip prosthesis manufacturer, Corin Ltd, has demonstrated the potential of new enhanced wear resistant coatings to increase implant longevity in Metal-on-Metal (MoM) hip prostheses and future potential applications to trunnions and tapers to prevent fretting and corrosion.
New PVD silver bearing coatings were developed which may protect against post-operative infection, and also provide a barrier to minimise metal ion release. Optimised coatings reduced the release of one important metal ion (Cobalt), implicated in chronic tissue inflammation, by 99 per cent.
Inherent wear resistance, anti-leaching and anti-microbial benefits have the potential to substantially reduce the lifetime cost of hip replacement implants to the UK...
