Foot and Ankle Injuries

Abstract

Man's foot is all his own. It is unlike any other foot. It is the most distinctly human part of the whole of his anatomical make-up.Wood Jones (1944) [ 1 ]The goal of this chapter is to further the understanding of pathomechanisms, performing diagnostics and reconstructing of injured feet, and to demonstrate ways to treat malunions and nonunions. Regaining anatomic joints if possible and rebuilding the normal shape of the foot, even by fusion of joints, is a safe way to avoid pain and to restore function. Anatomy of the FootThe human foot contains 28 bones and is divided into three parts: the forefoot, the midfoot, and the hindfoot ( Fig. 28.1 ) [ 3 , 4 ]. ForefootThe forefoot contains the fi ve metatarsals and toes with two sesamoids under the fi rst metatarsal head and an inconstant sesamoid beneath the fi rst interphalangeal joint. Six weight-bearing surfaces are located at the metatarsophalangeal level (two sesamoids and four lesser metatarsal heads) and fi ve weight-bearing surfaces are located under the distal phalanges in a normal foot.The metatarsals are short tubular bones with a base, shaft, neck, and head. The heads of the metatarsals are strongly connected by the intermetatarsal ligaments. The fi fth metatarsal has a tuberosity at its base, where the plantar aponeurosis, the peroneus brevis, and the peroneus tertius tendon insert.The fi rst toe has two phalanges and the other four toes have three phalanges. The fi rst metatarsal is slightly shorter, broader, and more mobile than the three middle metatarsals, and normally bears as much as one-third to one-half of the body weight through the forefoot and plays a key role in the gait cycle. The metatarsophalangeal joints are ellipsoidal joints, but only the fi rst and fi fth rays allow fl exion/extension and ab-/adduction. The joint capsules are strengthened by collateral ligaments on either side.The two sesamoids at the fi rst metatarsophalangeal joint are well embedded in the capsuloligamentous complex; the medial (tibial) sesamoid is larger than the lateral (fi bular) sesamoid, corresponding to its more important role in weight bearing within the medial sulcus of the metatarsal head.The sesamoids are held together by the strong intersesamoid ligament and the plantar plate, which is fi rmly attached at the base of the proximal phalanx and loosely attached at the neck of the metatarsal via the capsule. The sesamoids are located within the two slips of the fl exor hallucis brevis tendon. The abductor hallucis tendon inserts at the medial sesamoid, the adductor hallucis tendon at the fi bular sesamoid.