Knee cartilage does not regenerate on its own because it does not contain any blood vessels. Researchers have found a way to regrow cartilage using the patient's own cells.
The procedure, which can cost upwards of $30,000 as of 2015, involves taking a piece of cartilage from a non-weight-bearing part of the patient's knee. The cells from that cartilage are multiplied into millions of cartilage-producing cells. During the follow-up procedure, those cells are used to fill in the original hole, which is then closed up by patching the tissue. The cartilage layer is smooth and allows normal movement of the knee. The entire healing process can take more than a year, as the new cartilage needs time to mature. Success depends on the health of the patient's cells and other factors. Some patients can regain 90 percent of their normal activity.