With another exciting football season well underway, athletes all over the country are putting enormous strains and stresses on their cartilage, the connective tissue between bones that absorbs shock and helps joints move smoothly. Cartilage is a remarkable tissue, but with such punishing forces applied to it, cartilage is sometimes damaged. A new procedure we’re studying at Emory Sports Medicine – cartilage transplantation – may offer an alternative approach to cartilage repair.
Cartilage damage is common in active people, particularly among those who play sports that involve lots of pivoting and twisting. Basketball, soccer, football… basically any sport involving a ball and running increases the risk of a cartilage injury, most commonly in the knees, ankles, and hips. In many cases, these injuries cause no serious, long-term problems. But sometimes a chip, divot, or hole in cartilage can cause significant pain and mechanical symptoms such as clicking, catching, and locking up of the affected joint.
Standard approaches to cartilage repair include scraping or smoothing the damaged cartilage, or poking a hole in the underlying bone to provoke a blood clot and a healing response. Emory Sports Medicine is one of only 25 centers around the country studying cartilage transplantation.
Cartilage transplantation repairs damaged cartilage with replacement cartilage. We mix the donated cartilage with fibren glue (a common medium for biological repairs), form it into a patch of the appropriate size and shape, and insert it into the damaged area. Low and behold, it knits with the surrounding cartilage, stays in place, and forms new, healthy cartilage.
Unlike with many organ transplants, a cartilage transplant does not provoke a harmful immune response that could lead to rejection of the transplant. Cartilage is “avascular”: it doesn’t have any blood elements in it for the body to reject. This is why cartilage heals so slowly on its own, but it is also why we are able to transplant it without risk of rejection. It is what we call “immune-privileged tissue,” tissue that does not provoke an immune response.
Cartilage transplantation is still a new procedure. The study in which Emory Sports Medicine is participating will help us better determine the pros and cons of it in comparison to other approaches to cartilage repair. Will a repair made with actual replacement cartilage offer an expedited or improved recovery? We don’t yet know, but I can’t wait to find out.