Osteochondritis dissecans (OCD) is a condition in which a piece of bone or cartilage (or both) inside a joint loses blood supply and dies. OCD may be caused by injury or overuse from an activity that repeatedly jams one bone end against another.

OCD may not cause any symptoms, or symptoms may begin suddenly, develop gradually, or come and go. The condition may be discovered by accident if an X-ray is taken for another reason.

Symptoms of OCD may include:

• Pain.
• Swelling.
• Grating in the joint.
• Decreased joint movement.
• Locking of the joint.

Symptoms that begin suddenly may be caused by a piece of bone or cartilage that has broken loose and moved into the joint. Degenerative arthritis may develop in the area affected by OCD.

Treatment focuses on resting the joint to allow the cartilage and bone to heal and the swelling to decrease. The bone may take a full year to heal. Surgery may be necessary to remove loose pieces of bone.