The ankle joint comprises three bones, the tibia, fibula and talus, together with the ligamentous structures which bind them together. Three groups of ligaments can be distinguished: the deltoid ligament medially, between tibia and talus; the lateral collateral ligaments laterally, comprising anterior talofibular, calcaneofibular and posterior talofibular ligaments; and the syndesmosis complex, comprising the interosseous membrane between tibia and fibula, anterior tibiofibular, posterior tibio-fibular, inferior transverse and interosseous ligaments (Figure 1). Together, these structures allow movement of the talus within the mortise joint formed by tibia and fibular of 30° of dorsiflexion and 45° of plantar flexion.