As of 2015, cartilage replacement for arthritis in the knee is not a viable possibility, states About Health. Although cartilage cells can be cloned in a lab, placing the cells in a specific area and getting them to function while withstanding immense force presents a complex issue.
Although small numbers of cartilage cells can be inserted into patients, they have only been used to fill small holes and cannot replace a worn-out arthritic joint, says About Health. As of 2015, cartilage replacement techniques are only useful for patients with small areas of cartilage damage such as those caused by sports injuries. In order for a larger procedure to succeed, researchers must find a way to have the body accept new cartilage, adhere the cells to the joint surface and create cartilage that can both support body weight and allow for effective motion.
One major problem is that cartilage tissue is more than just cartilage cells, also including collagen, water and certain proteins, according to About Health. Injecting only cartilage cells fails to address these vital components. An issue with using cartilage replacement for knee arthritis is that the condition progressively damages the joint as rounded ends of bone become flattened and bone spurs form, making complete restoration difficult even with successful cartilage replacement.