Anti-aging injection shows promise in re-growing knee cartilage

Scientists at Stanford Medicine have reported a discovery that could change how arthritis and joint damage are treated.

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In experiments on animals and human tissue, researchers found that blocking a protein linked to aging can restore worn cartilage in the knee and prevent arthritis after injury. The treatment works not by adding stem cells, but by reprogramming existing cartilage cells to behave in a more youthful way.

In aging mice, an injectable drug rebuilt knee cartilage that normally thins with age. In mice with knee injuries similar to anterior cruciate ligament tears, the same treatment prevented the onset of arthritis, a condition that often follows such injuries in humans. A pill form of the drug is already being tested in early clinical trials for age-related muscle weakness, raising hopes that a similar approach could one day be used for joints.

Human knee cartilage removed during joint replacement surgery also responded to the treatment. When exposed to the drug in the laboratory, the tissue began forming new cartilage that resembled healthy, functional joint cartilage. These findings suggest that cartilage lost to aging or arthritis might eventually be restored through injections into the joint or even oral medication, potentially reducing the need for knee and hip replacements.

Osteoarthritis affects about one in five adults in the United States and costs tens of billions of dollars annually in direct health care spending. Despite its prevalence, there is no drug that can stop or reverse the disease. Current treatment focuses on pain relief, physical therapy and, in advanced cases, joint replacement surgery.