An osteochondral lesion of the talus is a small fracture or lesion of the cartilage that covers the talus, which is the lowest bone of the ankle joint. In some cases, there may also be damage to the bone itself. This condition is sometimes called an osteochondral fracture or osteochondritis dessicans. However, it should not be confused with osteochondritis dessicans of the knee.
This condition may be caused by either a traumatic injury, such as a sprained ankle, or over time to repetitive movement or overuse.