Subtalar (talocalcaneal) joint

Study entry

Classification

A single synovial joint (the anatomical subtalar) between the posterior articular surface of the talus, slightly concave, and the posterior articular surface of the calcaneus, convex.

Surfaces

Talus on the calcaneus. Orthopedists call subtalar the functional compound joint: the anatomical one plus the talocalcaneal part of the talocalcaneonavicular joint, which straddle the interosseous talocalcaneal ligament and work as a unit.

Capsule

A weak capsule, reinforced by the medial, lateral, posterior and interosseous talocalcaneal ligaments; the latter lies in the tarsal sinus, which separates the subtalar from the talocalcaneonavicular joint, and is especially strong.

Movements

This is where most of inversion and eversion takes place, about an oblique axis.

Blood supply

[CHECK: Moore does not describe it in the passages consulted (look in another source).]

Innervation

[CHECK: Moore does not describe it in the passages consulted (look in another source).]

Source: cap. 7, «Articulaciones del miembro inferior»: articulación subtalar

Clinical correlation

Fracture of the calcaneus

A hard fall on the heel, from a ladder for example, can break the calcaneus into several fragments (comminuted fracture). It is usually disabling because it disrupts the subtalar joint, where the talus rests on the calcaneus.

Related clinical cases

Fracture of the calcaneus