Posterior talocalcaneal ligament

At a glance

English

Posterior talocalcaneal ligament

Latin (TA2)

Ligamentum talocalcaneum posterius

System

Ligament

Region

Foot

Side

Paired, left and right

About the posterior talocalcaneal ligament

The posterior talocalcaneal ligament closes the back of the posterior subtalar joint, the larger of the two articulations between the underside of the talus and the calcaneus. The band itself is brief. Its narrow upper end is fixed to the lateral tubercle of the posterior process of the talus, and from there its fibres spread out downwards to the upper surface of the calcaneus and its medial side.

The posterior process of the talus has two tubercles, lateral and medial, with a groove between them for the tendon of flexor hallucis longus. This ligament springs from the lateral tubercle, just beside that groove, so the tendon passes immediately medial to it on its way down to the sole. Above and behind lies the posterior talofibular ligament, which also attaches to the lateral tubercle, and behind the ligament is a pad of fat that separates the joint from the Achilles tendon.

With the lateral and medial talocalcaneal ligaments, it forms part of the thin capsular wrapping around the posterior subtalar joint. These are minor stabilisers; the main bond between talus and calcaneus is the interosseous talocalcaneal ligament, which fills the tarsal canal further forwards. The posterior band limits the talus from tipping forwards off the calcaneus and helps keep the posterior facets in contact during inversion and eversion.

The lateral tubercle is sometimes a separate small bone, the os trigonum, joined to the talus by fibrous tissue. Forced pointing of the foot, as in ballet or football, can trap it between the tibia and calcaneus, producing pain at the back of the ankle known as posterior impingement. The ligaments attached to the tubercle, including this one, are then involved in the painful area.

Attachments and function

Attaches from

The lateral tubercle of the posterior process of the talus.

Attaches to

The top of the calcaneus and its medial side, its fibres fanning out from the narrow talar attachment.

Function

Closes and reinforces the back of the posterior subtalar joint and helps hold the talus on the calcaneus.

Nerve supply

Articular branches of the tibial and sural nerves.

Blood supply

Branches of the posterior tibial and fibular arteries.