Head of talus is enveloped by the acetabulum pedis that consists of:
• concave posterior surface of the navicular
• middle and anterior facets of sustentaculum tali of the calcaneus
• dorsal surface of plantar calcaneonavicular (spring) ligament
Spring/calcaneonavicular ligament – connects sustentaculum tali to navicular
Laterally the joint is supported by the calcaneonavicular portion of the bifurcate ligament – the medial band of the ‘Y’.