The joint consists schematically of lubricant (synovial liquid), and of 2 surfaces that face composed of bone and cartilage. Osteochondritis is a detachment of a fragment of cartilage and the bone under that cartilage.
At the ankle level, it most often interests the upper part of the astragal (dome). The astragal, or talus, is below the tibia and fibula, and above the calcaneum (heel bone).
The causes can be traumatic or not (in this case, we are talking about illness). It can be manifested by blockages (feeling of an intra-articular foreign body), or by pain related to load transfers due to the absence of cartilage. The imaging record includes standard x-rays, and an arthro-scanner or MRI.
First, medical treatment is attempted, with adaptation of sports practices, orthopedic soles, and infiltrations. Surgery can be an arthroscopy or an open-sky cleaning of the bone-cartilage fragment. In some lesions, a bone-cartilage fragment can be grafted from the knee (mosaicplasty)