Q. My 14 year old son was recently diagnosed with Osteochondritis Dissecans (OCD) of the knee. His doctor said that it can sometimes be serious and at times require pretty major surgery. He has been taken out of sports indefinitely. What causes this problem and what should I do?

A. OCD is a problem that we don’t fully understand. Basically, what happens is that an area of bone that supports the knee joint surface can lose its blood supply becoming “avascular”. This results in death of bone cells that are the normal support structure for the joint surface. It happens usually in younger teenagers and the causes are unknown. We are not certain if trauma or injury is related since this can happen spontaneously without injury. The area of damage can be small and asymptomatic (without symptoms) and even heal spontaneously. Also, things can be more problematic. At times, the area of damage can be disrupted and detached causing a large fragment of bone and joint surface (osteochondral) to loosen or even break off into the knee joint and form a “loose body”.  

The treatment depends on the size of the lesion and the stage as well as symptoms. Younger patients who are still growing probably have the best chance of healing this problem without surgery. X-rays and MRI are very useful in determining the treatment, which can range from observation only (with continued sports and activities), to indefinite periods out of sports, possible casting or immobilization, and even surgery. If surgery is required there are many newer options to fully resolve this problem. Early evaluation and treatment by a knee specialist is essential to help determine proper treatment.