When osteochondritis dissecans (OCD) affects the knee, it’s mostly at the end of the big bone of the thigh (an area called the femoral condyles. A joint surface damaged by OCD doesn’t heal naturally. Even with surgery, OCD can lead to future joint problems, including degenerative arthritis and osteoarthritis.
That’s why the care and management of this problem are important. Getting the best results possible may help prevent problems later. The problem occurs where the cartilage of the knee attaches to the bone underneath. The area of bone just under the cartilage surface is injured, leading to damage to the blood vessels of the bone. Without blood flow, the area of damaged bone actually dies. This area of dead bone can be seen on an X-ray and is sometimes referred to as the osteochondritis lesion.
The lesions usually occur in the part of the joint that holds most of the body’s weight. This means that the problem area is under constant stress and doesn’t get time to heal. It also means that the lesions cause pain and problems when walking and putting weight on the knee. It is more common for the lesions to occur on the medial femoral condyle, because the inside of the knee bears more weight.
Nonsurgical treatments help in about half the cases of OCD affecting children (called juvenile OCD or JOCD). The goal is to help the lesions heal before growth stops in the thighbone. Even if imaging tests show that growth has already stopped, it is usually worth trying nonsurgical treatments. When these treatments work, the knee seems as good as new, and the JOCD doesn’t seem to lead to arthritis.
Some patients who are too near the end of bone growth may not benefit with nonsurgical treatment. Surgery may also be advised if and when the lesion becomes totally or partially detached. There are several ways to fix it in place. In some cases, the loose fragment will just have to be removed.
Repeat imaging studies help surgeons see where the lesion is and how deep, large, or severe it may be. This information can be extremely valuable in planning the next step in treatment. Although there isn’t enough reliable evidence to support this practice, experts who treat OCD agree that serial X-rays and/or MRIs to assess healing are advised for patients who still have symptoms even after the first round of treatments.