The fractures in this region include Pott's fracture, and its converse; separation of the lower epiphysis of the tibia; fractures of the talus, calcaneus, and other tarsal bones; and fractures of the metatarsals and phalanges. Various dislocations also occur, the most important being those of the ankle joint, of the talus, and the sub-taloid dislocation.
#Surgical Anatomy.#--For the study of injuries in the region of the ankle-joint it is of importance to define the terms employed in describing the movements of the foot. Thus by _flexion_ or _dorsiflexion_ is meant that movement which approximates the dorsum of the foot to the front of the leg; while _extension_ or _plantar flexion_ means the drawing up of the heel so that the toes are pointed. In _inversion_ the medial edge of the foot is drawn up so that the sole looks towards the middle line of the body, an attitude which is analogous to supination of the hand. In _eversion_ the lateral edge of the foot is drawn up, the sole looking away from the middle line--analogous to pronation of the hand. _Adduction_ indicates the rotation of the foot so that the toes are turned towards the middle line of the body; while in _abduction_ the toes are turned away from the middle line.
The most prominent bony landmarks in the region of the ankle are the two _malleoli_, the lateral lying slightly farther back, and about half an inch lower than the medial. On the medial side of the foot from behind forward may be felt the _medial process (internal tuberosity)_ of the calcaneus; the _sustentaculum tali_, which lies about 1 inch vertically below the tip of the malleolus; the _tubercle of the navicular_, about 1 inch in front of the malleolus, and at a slightly lower level; the _first (internal) cuneiform_, and the base, shaft, and head of the _first metatarsal_.
On the lateral side may be recognised the _lateral process (external tuberosity)_ of the calcaneus; the _trochlear process (peroneal tubercle)_ on the same bone; the _cuboid_; and the prominent base of the _fifth metatarsal_.
The talo-navicular joint lies immediately behind the tuberosity of the navicular, and a line drawn straight across the foot at this level passes over the calcaneo-cuboid joint.