Grow your own joints

Doctors may one day be able to get patients who need hip and knee replacements to grow their own parts – within the body, scientists reported today.

Laboratory studies have shown a "grow your own" replacement operation can work successfully, according to a report in The Lancet.

The procedure would use a patient’s own stem cells to regrow cartilage and bone in the damaged joint.

It would not spare patients from surgery – as it requires surgeons to implant a "scaffold" to which the cells attach themselves and grow.

The procedure has been tested in laboratory studies by Professor Jeremy Mao, of Columbia University, New York, USA.

It was tested on rabbits and after four weeks the rabbits were able to resume normal movements.

Professor Mao said today: "This is the first time an entire joint surface was regenerated with return of functions including weight bearing and locomotion.

"Regeneration of cartilage and bone both from the host’s own stem cells, rather than taking stem cells out of the body, may ultimately lead to clinical applications."

Professor Mao said successful procedures in humans would prove more difficult – partly because human joints have to bear more weight.

Writing in the same journal, Dr Patrick Warnke, of Bond University, Gold Coast, Australia, said: "The optimum way to grow a biological joint remains a controversy. Although we are yet to see a biological joint replacement in man, they have offered a promising insight into what might be on the horizon."

The Lancet on-line July 28 2010