Study: New Procedure Raises Prospect of Regenerating Knee and Hip Joints

A new process that turns adult stem cells into bone and cartilage raises the prospect of using a patient's own tissue to regenerate arthritic knee and hip joints.

As reported in the December issue of the Journal of Dental Research, researchers at the University of Illinois-Chicago formed the ball structure of a joint known as a condyle, which is the ball structure of joints found in the jaw, knee and hip.

"This represents the first time a human-shaped articular condyle with both cartilage- and bone-like tissues was grown from a single population of adult stem cells," said lead researcher Jeremy Mao, director of the university's tissue engineering laboratory.

Mao and his colleague Adel Alhadlaq, a doctoral student in anatomy and cell biology, said they ultimately would like to create a biologically viable condyle that integrates with existing bone and functions like a natural joint.

Mao said much additional work is needed before tissue-engineered condyles are ready for therapeutic use in patients suffering from osteoarthritis, rheumatoid arthritis or congenital anomalies. Nevertheless, he believes that with further refinements, the procedure could one day be adopted for total hip and knee replacements.

To create the articular condyle, Mao and a colleague used adult stem cells taken from the bone marrow of rats. Present in a number of adult tissues, such cells can potentially transform themselves into virtually any kind of connective tissue -- including tendons, skeletal muscle, teeth, ligaments, cartilage and bone, according to the researchers.

Using chemical substances and growth factors, the scientists induced the adult stem cells to develop into cells capable of producing cartilage and bone. The cells were then stratified into two layers, encapsulated in a gel-like material and shaped into an articular condyle using a mold made from the jaw joint of a human cadaver.

Mao said the finding proves that the concept of transforming adult stem cells into bone and cartilage can really be accomplished.

Other sources: University of Illinois at Chicago