Scientists make breakthrough for damaged knees

Stanford University scientists have had a major breakthrough that could lead to future knee injuries being repaired with a simple injection or oral medication.

The researchers also say it could mean far fewer people in the future needing knee and hip replacement surgeries.

The work was done with mice, the researchers targeting a specific protein that causes cartilage to break down.

Lead authors Dr Helen Blau and Dr Nidhi Bhutani said by blocking that protein in older mice, they found cartilage that had thinned had actually grown thicker.

"Osteoarthritis affects about 240 million people worldwide," Blau told Nine to Noon.

"Right now, the only thing that is offered is pain medications to deal with the pain of osteoarthritis, and also when it's particularly bad, then you can get knee replacement or hip replacement surgery."

The scientists discovered an enzyme which, if blocked, could restore muscle mass and muscle strength - and further testing allowed them to do the same with cartilage.

"What we see is that these cells are now able to reprogram into a younger phenotype," Bhutani said.

Blau said the drug had been through a phase one clinical trial which showed it is safe for use in humans.

"We have the green light from the [US Food and Drug Administration] to proceed to phase 2b trials in sarcopenia, muscle wasting for ageing."

Bhutani said the research could be a "gamechanger".