Patients to grow own hip, knee replacements

London, (IANS) - Patients with knee or hip problems will be able to 'grow' new replacement joints in the future, scientists say.

Researchers have shown it is possible to grow properly working joints inside the body using a patient's own stem cells, after the damaged bone has been removed.

They say the joints will have a full range of movement, be able to bear weight and may even last longer than the current generation of artificial devices, the Daily Mail reports.

That would save patients from repeat surgery after their original hip or knee replacement, which usually lasts 15-20 years, has worn out.

An American team carried out a pioneering study on rabbits and believes it paves the way for a future where people can grow bone and cartilage inside their own bodies.

They used a computer to help create artificial frames that were the same size and shape as rabbit hip joints.

These frames were infused with a growth hormone and implanted into rabbits after the animals' hip joints had been removed.

Attracted by the growth hormone, the rabbits' own stem cells went to the location of the missing joint and regenerated cartilage and bone in two separate layers.

Just three to four weeks after surgery, the rabbits had fully regained movement and could bear weight similar to animals who had never undergone surgery, according to the study published in The Lancet medical journal.

The rabbits had grown the joints using their stem cells, instead of relying on an injection of stem cells into their body.

This is the first time scientists have regenerated a complete limb joint using either harvested stem cells or an animal's own stem cells.

Previously scientists have grown 'spare part tissue' in the lab from patients' stem cells for use in repairing diseased organs, including heart valves and bladders.

Lead researcher Professor Jeremy Mao of New York's Columbia University, said: "This is the first time an entire joint surface was regenerated with return of functions, including weight bearing and locomotion.

"In patients who need the knee, shoulder, hip or finger joints regenerated, the rabbit model provides a proof of principle," he added.