Calcaneus

Calcaneus or Calcaneum is the largest of the tarsal bones is the largest bone of the foot.

The posterior half of the bone is the tuber calcanei. On its lower edge on either sides are its lateral and medial processes which serve as the origins of the abductor hallucis and abductor digit minimi. The Achilles tendon is inserted into a roughened area on its superior side, the cuboid bone articulates with its anterior side, and on its superior side are three articular surfaces for the articulation with the talus bone.

Between these superior articulations and the equivalents on the talus is the tarsal sinus  which is a canal occupied by the interosseous talocalcaneal ligament.

On the medial side of the bone, below the middle talar facet, is the sustentaculum tali which serves for the attachment of several other ligaments. On the lateral side is commonly a tubercle called the peroneal trochlea, under which is a groove for the tendon of the peroneus longus.

Left Calcaneus, Superior Aspect

Left Clcaneus, Medial Aspect

The ossification center is developed during the 4-7th intrauterine month.

Left Calcaneus, Lateral Aspect

With normal axial alignment in the hindfoot, the axes of the tibia and calcaneus lie on a vertical line (pes rectus). If the calcaneal axis is turned medially the foot is in an everted position (pes valgus), and if it is turned laterally the foot is in an inverted position (pes varus).

The cacaneus gets injured commonly in fall from height cases.

Text & Images Credit-Wikipedia