Scientists have discovered how to regenerate entire joint surfaces using the patients stem cells.
Credit: University of Michigan
PARIS: Scientists have shown for the first time that it may be possible to replace a human hip or knee with a joint grown naturally inside the body using the patient's stem cells.
In experiments on rabbits, the researchers coaxed the animals' stem cells to rebuild the bone and cartilage of a missing leg joint, according to a new study.
"This is the first time an entire joint surface was regenerated with return of functions including weight bearing and locomotion," lead researcher, Jeremy Mao from Columbia University, said in a statement.
Longer-lasting than artificial mechanisms
Naturally-grown joints would likely last longer than the current generation of artificial mechanisms, he said.
With aging populations and many people under 65 requiring replacement surgery, there is a real danger patients will outlive metallic joints and require a second gruelling operation late in life.
In the experiments, Mao and colleagues removed the forelimb thigh joint of 10 rabbits, and then implanted a kind of scaffolding made of biologically compatible materials.
A naturally-occurring substance that stimulates cell growth then cued the rabbits' stemcells to go to the site of the missing joint and regenerate both cartilage and bone in two distinct layers.
Within four weeks, the animals resumed normal movements - a medical first, the researchers reported in The Lancet.
Potential regeneration of multiple joints
The fact that the regenerated limb joint was created from the stem cells in the host animal - rather than being harvested and then cultivated outside the body - is also unprecedented, they said.
This new procedure "may ultimately lead to clinical applications," said Mao. "In patients who need the knee, shoulder, hip or finger joints regenerated, the rabbit model provides a proof of principle."
