The anterior and middle facets articulate with adjacent surfaces on the calcaneus bone.
The other facet, medial to the facets for articulation with the calcaneus, articulates with a ligament—the plantar calcaneonavicular ligament (spring ligament)—which connects the calcaneus to the navicular under the head of the talus.
The neck of the talus is marked by a deep groove (the sulcus tali), which passes obliquely forward across the inferior surface from medial to lateral, and expands dramatically on the lateral side. Posterior to the sulcus tali is a large facet (posterior calcaneal surface) for articulation with the calcaneus.
The superior aspect of the body of the talus is elevated to fit into the socket formed by the distal ends of the tibia and fibula to form the ankle joint:
The upper (trochlear) surface of this elevated region articulates with the inferior end of the tibia.
The medial surface articulates with the medial malleolus of the tibia.
The lateral surface articulates with the lateral malleolus of the fibula.
Because the lateral malleolus is larger and projects more inferiorly than the medial malleolus at the ankle joint, the corresponding lateral articular surface on the talus is larger and projects more inferiorly than the medial surface.
The lower part of the lateral surface of the body of the talus, which supports the lower part of the facet for articulation with the fibula, forms a bony projection (the lateral process).
The inferior surface of the body of the talus has a large oval concave facet (the posterior calcaneal articular facet) for articulation with the calcaneus.
The posterior aspect of the body of the talus consists of a backward and medially facing projection (the posterior process). The posterior process is marked on its surface by a lateral tubercle and a medial tubercle, which bracket between them the groove for  the tendon of the flexor hallucis longus as it passes from the leg into the foot.
The calcaneus sits under and supports the talus. It is an elongate, irregular, box-shaped bone with its long axis generally oriented along the midline of the foot, but deviating lateral to the midline anteriorly (Fig. 6.98).
The calcaneus projects behind the ankle joint to form the skeletal framework of the heel. The posterior surface of this heel region is circular and divided into upper, middle, and lower parts. The calcaneal tendon (Achilles tendon) attaches to the middle part:
The upper part is separated from the calcaneal tendon by a bursa.
The lower part curves forward, is covered by subcutaneous tissue, is the weight-bearing region of the heel, and is continuous onto the plantar surface of the bone as the calcaneal tuberosity.
The calcaneal tuberosity projects forward on the plantar surface as a large medial process and a small lateral process separated from each other by a V-shaped notch (Fig. 6.98B). At the anterior end of the plantar surface is a tubercle (the calcaneal tubercle) for the posterior attachment of the short plantar ligament of the sole of the foot.
The lateral surface of the calcaneus has a smooth contour except for two slightly raised regions (Fig. 6.98C). One of these raised areas—the fibular trochlea (peroneal tubercle)—is anterior to the middle of the surface and often has two shallow grooves, which pass, one above the other, obliquely across its surface. The tendons of the fibularis brevis and longus muscles are bound to the trochlea as they pass over the lateral side of the calcaneus.
Superior and posterior to the fibular trochlea is a second raised area or tubercle for attachment of the calcaneofibular part of the lateral collateral ligament of the ankle joint.