The talocalcaneonavicular joint is a

ball and socket joint The ball-and-socket joint (or spheroid joint) is a type of synovial joint in which the ball-shaped surface of one rounded bone fits into the cup-like depression of another bone. The distal bone is capable of motion around an indefinite number of ...

in the foot; the rounded head of the talus is received into the concavity formed by the posterior surface of the

navicular The navicular bone is a small bone found in the feet of most mammals. Human anatomy The navicular bone in humans is one of the tarsus (skeleton), tarsal bones, found in the foot. Its name derives from the human bone's resemblance to a small ...

, the anterior articular surface of the

calcaneus In humans and many other primates, the calcaneus (; from the Latin ''calcaneus'' or ''calcaneum'', meaning heel; : calcanei or calcanea) or heel bone is a bone of the Tarsus (skeleton), tarsus of the foot which constitutes the heel. In some other ...

, and the upper surface of the

plantar calcaneonavicular ligament The plantar calcaneonavicular ligament (also known as the spring ligament or spring ligament complex) is a complex of three ligaments on the underside of the foot that connect the calcaneus with the navicular bone. Structure The plantar calcaneo ...

Structure

As its shape suggests, this joint is a synovial

ball-and-socket joint The ball-and-socket joint (or spheroid joint) is a type of synovial joint in which the ball-shaped surface of one rounded bone fits into the cup-like depression of another bone. The distal bone is capable of motion around an indefinite number of ...

. It is composed of three articular surfaces: * The articulation between the medial talar articular surface on the sustentaculum tali of the superior calcaneus and the corresponding medial facet found inferiorly on the talus neck * The articulation between the anterior talar articular surface of the superior calcaneus and the anterior facet of the corresponding talus found inferiorly on the talar head * The articulation between the articular surface of navicular and the head of talus (talonavicular joint)

Ligaments

The

also called the spring ligament forms the whole floor of the talus as it extends inferior to the talus. It attaches to the anterior aspect of sustentaculum tali inserting into the plantar surface of navicular. By beginning from sustentaculum tali it covers the plantar surfaces of the middle and anterior articulations between the calcaneus and talus and by attaching to the navicular it covers the articulation between the talus and navicular. That is a reason why the medial longitudinal arch of the foot is a bit higher than the lateral longitudinal arch of the foot as this ligament is a main part of it. The calcaneonavicular part of the bifurcated ligament extends from the dorsolateral side of calcaneus (near the tarsal sinus) to the lateral side of the navicular. It reinforces the joint particularly laterally where the talus articulates with the navicular. The dorsal talonavicular ligament extends from the dorsal aspect of the foot from the neck of the talus to the navicular. The socket of this joint is formed by the concave articular facets of the navicular, calcaneus, calcaneonavicular part of bifurcate ligament and the spring ligament (plantar calcaneonavicular ligament), where the ball is formed by the convex talus.

References

Bones of the lower limb {{Musculoskeletal-stub