The lateral talocalcaneal ligament is a flat fibrous band on the lateral aspect of the subtalar joint, running from the lateral surface of the talus downward and backward to the lateral surface of the calcaneus. It is distinct from and lies anterior to the calcaneofibular ligament, reinforcing the lateral subtalar joint capsule and resisting inversion stress at the level of the subtalar joint rather than the ankle mortise.
Resists inversion and distraction at the subtalar joint, complementing the interosseous talocalcaneal and cervical ligaments in stabilising the posterior subtalar articulation against inversion forces transmitted from the hindfoot.
The lateral talocalcaneal ligament is disrupted in severe lateral ankle sprains that also involve the subtalar joint complex. Subtalar instability, an underrecognised entity producing hindfoot giving way and difficulty on uneven surfaces, involves failure of the lateral talocalcaneal, cervical, and interosseous talocalcaneal ligaments. Stress inversion radiography or stress MRI is required for diagnosis. The ligament is identified during open subtalar stabilisation procedures and peroneal tendon surgery.
Chronic laxity of the lateral talocalcaneal and cervical ligaments after repeated ankle sprains produces hindfoot instability with giving way on uneven ground and subtalar stress laxity on imaging, managed with physiotherapy and, when conservative measures fail, subtalar stabilisation surgery using ligament reconstruction or bone block procedures.
