Stem cells refer to the basic cell before it differentiates or turns into a specific type of cell. The value in using stem cells is that when injected into a damaged or diseased area, they can produce healthy cells of whatever type is needed. For example, when placed in a hole in the articular cartilage, they reproduce to form many new cartilage cells. In this way, they enhance and speed up the healing process.

Some stem cells are multipotent. This means they have the ability to turn into more than one type of cell. Adult stem cells don't do this as well, or as easily, as embryonic cells. But with careful treatment in the laboratory setting, enough adult stem cells can be made to use for healing or regenerating tissues.

Arthritis is one condition that has come up whenever stem cell research is mentioned. The ability to repair and restore cartilage and bone tissue would be miraculous for many older adults suffering from this disabling condition.

Right now this research is still in the early phases. It is not available yet for the everyday patient. Scientists haven't been able to always get stem cells to make true articular cartilage. Sometimes a weaker, fibrocartilage is formed instead. Finding the optimal conditions to grow cartilage tissue is the focus of some studies in the area of tissue engineering.