Advanced hard coatings specialist Wallwork Cambridge has been awarded funding from Innovate UK to research the medical application of such a process.

The firm says that knee and hip replacements are usually made from an alloy of cobalt, chrome and molybdenum (CoCrMo) or from ceramics. These materials are sometimes used in hybrid structures in combination with high density polymers. Issues have arisen of metal-ion leakage from CoCrMo devices, plastic degradation and breakage or chipping of the ceramic implants in active individuals.

Wallwork is now developing a patented coating called Agilliant, which it says will provide an effective barrier against the release of metal ions and that also includes a small proportion of silver to give active protection from post-operative infection. The barrier is also effective against bio-tribo corrosion by the synovial fluid that still acts as a natural joint lubricant in artificial implants.

Explains Wallwork head of research and development Dr Jonathan Housden: “The duplex coating process, incorporating Agilliant as the final coating, opens the way for the introduction of a new generation of durable titanium implants.

“These will be lighter and more comfortable for the patient with fewer complications caused by post-operative infection and mechanical wear. Early trials to simulate many years of use suggest that the joints will, in many cases, outlive the patient, leading to a £300 million annual saving for the NHS by allowing more efficient use of orthopaedic resources as rework of failed or compromised treatments is reduced.”

Wallwork is collaborating with the Institute for Functional Surfaces at the University of Leeds in relation to the aerospace technology transfer. A major implant manufacturer and leading NHS centres are their project partners for the Agilliant coating.