Talus: The second largest of the TARSAL BONES. It articulates with the TIBIA and FIBULA to form the ANKLE JOINT.Osteochondritis: Inflammation of a bone and its overlaying CARTILAGE.Ankle Injuries: Harm or hurt to the ankle or ankle joint usually inflicted by an external source.Ankle Joint: The joint that is formed by the inferior articular and malleolar articular surfaces of the TIBIA; the malleolar articular surface of the FIBULA; and the medial malleolar, lateral malleolar, and superior surfaces of the TALUS.Ankle FracturesSubtalar Joint: Formed by the articulation of the talus with the calcaneus.Foot Deformities, Congenital: Alterations or deviations from normal shape or size which result in a disfigurement of the foot occurring at or before birth.Calcaneus: The largest of the TARSAL BONES which is situated at the lower and back part of the FOOT, forming the HEEL.Tarsal Bones: The seven bones which form the tarsus - namely, CALCANEUS; TALUS; cuboid, navicular, and the internal, middle, and external cuneiforms.Tarsal Joints: The articulations between the various TARSAL BONES. This does not include the ANKLE JOINT which consists of the articulations between the TIBIA; FIBULA; and TALUS.Clubfoot: A deformed foot in which the foot is plantarflexed, inverted and adducted.Casts, Surgical: Dressings made of fiberglass, plastic, or bandage impregnated with plaster of paris used for immobilization of various parts of the body in cases of fractures, dislocations, and infected wounds. In comparison with plaster casts, casts made of fiberglass or plastic are lightweight, radiolucent, able to withstand moisture, and less rigid.Arthroplasty, Replacement, Ankle: Replacement of the ANKLE JOINT.Byzantium: An ancient city, the site of modern Istanbul. From the 4th to 15th centuries the empire extended from southeastern Europe to western Asia, reaching its greatest extent under Justinian (527-565). By about 1000 A.D. it comprised the southern Balkans, Greece, Asia Minor, and parts of southern Italy. The capture of Constantinople in 1453 marked the formal end of the Byzantine Empire. (From Webster's New Geographical Dictionary, 1988)Arthroplasty, Subchondral: Surgical techniques used to correct or augment healing of chondral defects in the joints (CARTILAGE, ARTICULAR). These include abrasion, drilling, and microfracture of the subchondral bone to enhance chondral resurfacing via autografts, allografts, or cell transplantation.Heel: The back (or posterior) of the FOOT in PRIMATES, found behind the ANKLE and distal to the TOES.Arthroscopy: Endoscopic examination, therapy and surgery of the joint.Osteochondritis Dissecans: A type of osteochondritis in which articular cartilage and associated bone becomes partially or totally detached to form joint loose bodies. Affects mainly the knee, ankle, and elbow joints.