Osteochondritis dissecans is a joint problem that occurs when a piece of cartilage and a thin layer of bone separate from the end of a bone because of a loss of blood supply. The loose piece may stay in place or fall into the joint space, making the joint unstable. This causes pain and feelings that the joint "sticks" or is "giving way." These loose pieces are sometimes called "joint mice."
Osteochondritis dissecans most often occurs in the knees, but also may occur in other joints, including elbows, ankles, shoulders and hips.
The symptoms of osteochondritis dissecans include:
These are all clues that you may have osteochondritis dissecans. Your doctor will check you to be sure the joint is stable and check for extra fluid in the joint. Your doctor will consider all the possible causes of joint pain, including fractures, sprains and osteochondritis dissecans.
Anyone can get osteochondritis dissecans, but it happens more often in boys and young men 10 to 20 years of age who are very active. Osteochondritis dissecans is being diagnosed more often in girls as they become more active in sports. It affects athletes, especially gymnasts and baseball players. The adult form occurs in mature bone, and the juvenile form occurs in growing bone.
If osteochondritis dissecans is suspected, your doctor will order X-rays to check all sides of the joint. If signs of osteochondritis dissecans are seen on X-rays of one joint, you'll have X-rays of the other joint to compare them. After this, you may have an MRI (magnetic resonance imaging) or a CT (computerized tomography) done. These tests can show whether the loose piece is still in place or whether it has moved into the joint space.
If the loose piece is unstable (meaning it has moved into the joint space), you might need surgery to remove it or secure it. If the loose piece is stable (still in place) you may not need surgery, but you may need other kinds of treatment, such as resting the affected joint, bracing the joint when playing sports and treating pain and inflammation with ibuprofen.
If a nonsurgical treatment is recommended, you should avoid activities that cause discomfort. You should avoid competitive sports for 6 to 8 weeks. Your doctor may suggest stretching exercises or swimming instead as a means of physical therapy.
Young people have the best chance of returning to their usual activity levels, although they might not be able to keep playing sports with repetitive motions, such as pitching in baseball. Adults are more likely to need surgery and are less likely to be completely cured. They may later develop arthritis in the affected joint.
Osteochondritis Dissecans: A Diagnosis Not to Miss by AL Hixon, M.D. and LM Gibbs, M.D. (American Family Physician January 01, 2000, http://www.aafp.org/afp/20000101/151.html)
Written by familydoctor.org editorial staff