Now, broken knees can be mended by growing cartilage from stem cells

People who have damaged their knee joints can get them repaired with new cartilage grown from stem cells in a laboratory, according to a study at the UC Davis Department of Biomedical Engineering.

Already, professor Kyriacos Athanasiou and his colleagues used adult stem cells from bone marrow and skin as well as human embryonic stem cells, to grow cartilage tissue in the lab.

And now, they are experimenting with various chemical and mechanical stimuli to improve its properties.

Cartilage is one of the very rare tissues that lacks the ability to heal itself. When damaged by injury or osteoarthritis, the effects can be long lasting and devastating.

"If I cut a tiny line on articular cartilage (the cartilage that covers the surfaces of bones at joints), it will never be erased. It's like writing on the moon. If I go back to look at it a year later, it will look exactly the same," said Athanasiou.

Work that Athanasiou's group began in the early 1990s at Rice University has resulted in the only FDA-approved products for treatment of small lesions on articular cartilage.

"This will be live, biological cartilage that will not only fill defects, but will potentially be able to resurface the entire surface of joints that have been destroyed by osteoarthritis," said Athanasiou.

Currently, joint replacements using metal and plastic prosthetics are the only recourse for the one in five adults who will suffer major joint damage from osteoarthritis.