How do doctors identify this problem?rnrnYour doctor will ask many questions about your medical history. You will be asked about your current symptoms and about other knee or joint problems you have had in the past. Your doctor will then examine the painful knee by feeling it and moving it. You may be asked to walk, move, or stretch your knee. This may hurt, but it is important that your doctor knows exactly where and when your knee hurts.
Your doctor will probably order an X-ray of your knee. Most OCD lesions will show up on an X-ray of the knee. If not, your doctor may suggest a bone scan.rnrnA bone scan involves injecting a special type of dye into the blood stream and then taking pictures of the bones with a special camera. This camera is similar to a Geiger counter and can pick up very small amounts of radiation. The dye that is injected is a very weak radioactive chemical. It attaches itself to areas of bone that are undergoing rapid changes, such as a healing fracture. A bone scan is the best way to see the lesions in the very early stages.
Your doctor may want to do other imaging tests, such as magnetic resonance imaging (MRI). The MRI machine uses magnetic waves rather than X-rays to show the soft tissues of the body. With this machine, doctors are able to create pictures that look like slices of the knee and see the anatomy, and any injuries, very clearly. These tests may help determine the extent of damage from OCD and JOCD, and they also help rule out other problems.rnOCD mostly affects the femoral condyles of the knee. The femoral condyle is the rounded end of the lower thighbone, or femur. Each knee has two femoral condyles, referred to as the medial femoral condyle (on the inside of the knee) and the lateral femoral condyle (on the outside). Like most joint surfaces, the femoral condyles are covered in articular cartilage. Articular cartilage is a smooth, rubbery covering that allows the bones of a joint to slide smoothly against one another.
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.