Although often considered independently, the ankle and hindfoot joints have a symbiotic relationship. The ankle provides plantar flexion and dorsiflexion, while the hindfoot predominantly moves the foot into inversion and eversion. Together, these two joints act as a universal joint, allowing the foot to accommodate to uneven terrain while the leg remains vertical.

The hindfoot is made up of the talonavicular, subtalar, and calcaneocuboid joints. The talonavicular and subtalar joints are essential: their function is important for normal foot biomechanics. The calcaneocuboid joint is not as important; loss of this joint results in minor hindfoot stiffness.1 Many of the joints of the midfoot and forefoot are also not essential. Thus, assuming the same functional result can be obtained, arthrodesis of a midfoot joint is often preferred over that of a hindfoot joint.