Medial collateral ligament of ankle

The medial ligament of talocrural joint (or deltoid ligament) is a strong, flat, triangular band, attached, above, to the apex and anterior and posterior borders of the medial malleolus.

The Deltoid ligament is composed of the Anterior Tibiotalar Ligament, Tibiocalcaneal Ligament, Posterior Tibiotalar Ligament, and Tibionavicular Ligament. It consists of two sets of fibres, superficial and deep.

Of the superficial fibres,

• the most anterior (tibionavicular part) pass forward to be inserted into the tuberosity of the navicular bone, and immediately behind this they blend with the medial margin of the plantar calcaneonavicular ligament;
• the middle (tibiocalcaneal part) descend almost perpendicularly to be inserted into the whole length of the sustentaculum tali of thecalcaneus;
• the posterior fibres (posterior tibiotalar part) pass backward and lateralward to be attached to the inner side of the talus, and to the prominent tubercle on its posterior surface, medial to the groove for the tendon of the Flexor hallucis longus.

The deep fibres (anterior tibiotalar part) are attached, above, to the tip of the medial malleolus, and, below, to the medial surface of the talus.

The deltoid ligament is covered by the tendons of the Tibialis posterior and Flexor digitorum longus.

The anterior and posterior talofibular and the calcaneofibular ligaments were formerly described as the three fasciculi of the external lateral ligament of the ankle-joint.