New technique can extend life of hip replacements

Last Updated: Sep 02, 2012, 16:54 PM IST

London: Scottish researchers have developed a new technique which they claim could pave the way for hip replacements that last a lifetime.

Researchers from Glasgow`s Southern General Hospital are developing prototypes of a new system that aims at combating problems of the body forming soft tissues around hip replacements.

The new technique coats key surfaces with a "nanopattern" pitted plastic to encourage stem cells to form bone in contact with the new joint, the BBC News reported.

Usually, a hip replacement needs to be changed every 15 years.

Consultant orthopaedic surgeon Dominic Meek, from the hospital, said the hip replacement procedure had become a victim of its own success.

"One of the problems is that it`s been so successful that we`ve been putting them into a lot more, younger patients - and they`re a lot more active. So because of this they`ve been wearing out these hip joints," Meek was quoted as saying by the paper.

The implants also become loose because over the years stem cells in the patient`s bone marrow surround the implant with soft tissue.

The soft tissue around an implant means it starts to lose its grip. If the stem cells could be encouraged to form bone instead, it would create a joint fit for a lifetime.

The researchers believe the solution is a nanopattern - a pattern so small even the most powerful optical microscope can`t see it.

When the stem cells meet one particular nanopattern instead of soft tissue, bone grows.

"What we`ve done is control the pattern that we have to tell the stem cells what tissue we want them to form," cell biologist Dr Matthew Dalby, said.

"And by tuning the pattern we can tell the stem cells around the implant that we want them to form bone," Dalby was quoted as saying by the BBC.

The next step is to coat the key surfaces of an implant with the nanopattern.

The plastic is strong, doesn`t interact with a patient`s body chemistry, and doesn`t get in the way of X-Rays. It`s called polyether ether ketone - PEEK for short.

It will be shaped to include the tiny pits of the bone-growing nanopattern.

PTI