Q: What kind of treatment is prescribed for osteochondritis of the knee if surgery isn't done?


A: Osteochondritis dissecans (OCD) is a problem that affects the knee, mostly at the end of the big bone of the thigh (the femur). Repetitive motion, compression, and friction causes damage to the first layer of bone underneath the cartilage called subchondral bone.

As the condition becomes worse, the area of bone that is affected may collapse, causing a notch to form in the smooth joint surface. The cartilage over this dead section of bone may become damaged. This can cause a snapping or catching feeling as the knee joint moves across the notched area. In some cases the dead area of bone may actually become detached from the rest of the femur, forming what is called a loose body. This loose body may float around inside of the knee joint. The knee may catch or lock when it is moved if the loose body gets in the way.

Conservative care has evolved over time with evidence from studies to suggest optimal ways of supporting natural healing. At first, the approach was to prescribe immobilization and non-weightbearing of the leg. But it was quickly realized that this method left the patient with a stiff and weak knee that starts to lose bone mass from disuse. Today, the leg is still placed in an immobilizer, but partial weight-bearing is allowed until the patient no longer has any pain. That usually takes about six weeks.

The next phase of rehab involves increasing the weight put on the foot and leg and adding low-impact strengthening exercises. No one is allowed to participate in sports activities until X-rays show the bone is healed, there are no symptoms, and the patient has completed the full course of rehabilitation under the supervision of a physiotherapist.

If conservative care fails, then surgery is still an option. In all cases, the surgeon tries to preserve the natural cartilage by repairing the damage rather than removing and replacing the torn cartilage. Studies have shown that removing the torn fragment may give the patient relief from the pain and symptoms, but it doesn't last. Only one in four patients treated this way go on to heal completely. But sometimes repair just isn't possible and the damaged cartilage must be removed and replaced.

Cecilia Pascual-Garrido, MD, et al. Surgical Treatment Options for Osteochondritis Dissecans of the Knee. In Sports Health. July/August 2009. Vol. 1. No.4. Pp. 326-334.