Osteochondritis dissecans (os-tee-o-kon-DRY-tis DIS-uh-kanz) is a joint condition in which a piece of cartilage, along with a thin layer of the bone beneath it, comes loose from the end of a bone.
Osteochondritis dissecans occurs most often in young men, particularly after an injury to a joint. Osteochondritis dissecans is most common in the knee. But, osteochondritis dissecans can occur in other joints.
If the loosened piece of cartilage and bone stays close to where it detached, you may have few or no symptoms of osteochondritis dissecans, and the fracture may heal by itself. Surgical repair may be necessary if the fragment comes loose and gets caught between the moving parts of your joint, or if you have persistent pain.