Osteochondritis Dissecans (OCD) is a condition that affects joint cartilage, and the bone that supports the cartilage. OCD is the result of abnormal blood flow that causes weakening and fragmentation of the bone and cartilage. OCD can cause the cartilage to break free from it's attachment and become a loose body within the joint.
The cause of OCD is not well understood, but it is known that the blood flow to the bone that supports the cartilage is altered, causing the bone and cartilage to begin to loosen. OCD can occur in different age patients and different joints. It is most common in the knee, followed by the ankle and elbow. It can also occur in other joints, but much less commonly.
OCD is also very different depending on the age of the patient. In young patients with open growth plates, the prognosis for healing of the fragment is much better than in adults with closed growth plates.