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.
The condition occurs most often in young men, particularly after an injury to a joint. It’s most common in the knee, but can occur in other joints.
If the loosened piece of cartilage and bone stays close to where it was detached from, you may have few or no symptoms, and the fracture may heal by itself. However, 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.