OCD of the knee stands for osteochondritis dissecans, which is also known as juvenile OCD (or JOCD) when it occurs in children and teens. This condition occurs most often in athletes but can affect any physically active individual.
The forceful and repeated actions of sports can strain the immature surface of the knee joint in children and teens. The bone under the joint surface weakens and becomes injured, which damages the blood vessels going to the bone. Without blood flow, the small section of bone dies. The injured bone cracks. It may actually break off.
With rest and activity modification, the joint can begin the healing process. Surgery is usually reserved for children with more severe cases of JOCD or when conservative (nonoperative) care has failed to change the symptoms.
Studies show that the best way to get a good look at the condition of the joint surface and cartilage is to do an MRI. X-rays may look normal early in the condition when there is, in fact, a real problem. As the condition worsens, the X-ray image shows changes in the bone and joint.
The normal shape of the bony knob at the end of the femur (thigh bone) called the femoral condyle may appear irregular. In bad cases of knee juvenile OCD, the condyle might even look like it has flattened out, suggesting that the bone has collapsed. The X-ray could show a crack in the bone or even a loose body.
A magnetic resonance imaging (MRI) scan may show more detail. The MRI can give an idea of the size of the affected area. It can show bone irregularities and also help detect swelling. Doctors may repeat the MRI test at various times to see if the area is healing. MRIs are also very helpful when considering and/or planning surgery.
MRIs are “reliably sensitive” to articular (joint) surface lesions associated with juvenile osteochondritis dissecans (JOCD). Thickening of the articular cartilage and cracks or fissures in the cartilage are visible. Loose fragments of tissue and the hole or “defect” where the tissue came from are also visible.
The value of MRIs in children with OCD is that those who have unusual (atypical) lesions can get treatment early. MRIs help identify early changes that might go undetected otherwise. Untreated, OCD lesions can gradually get worse and lead to early joint arthritis.
The best thing to do is present the surgeon with your question. Given the information that insurance is not covering these expenses (and therefore finances are a consideration) it may be MRIs can be avoided. But the surgeon may have his or her reasons for requesting MRIs, especially if surgery is being planned. Get the full level of information before making your decision. Most imaging centers are willing to work with families to ensure full payment by spreading them over several months’ time.