The sinus tarsi, also known as the talocalcaneal sulcus,[1] is a cylindrical canal in the hindfoot.

It has a complex anatomy, with five ligamentous structures and a pad of adipose tissue (fat).

[3] The sinus tarsi helps stabilize the ankle, as the cervical ligament limits inversion of the (turning in) and the interosseous talocalcaneal ligament limits eversion (turning out).

This disorder can have a variety of causes; however, the most common is an inversion ankle sprain.

[5] In recent years, approaching a displaced intra-articular calcaneus fracture via the sinus tarsi during surgery has been found to be more efficient in reconstructing the bone and less invasive, preserving soft tissue around the bone.