Clfb-Foot, a deformity arising from rigidity and contraction of the muscles of the leg, in which the individual walks, with one or both legs, on the toes, on the external or internal border of the foot, or in some rare forms on the heel or the top of the foot. This deformity, which may be congenital or accidental, was known to Hippocrates; Celsus gave the names varus and valgus, which are still used, to two of the varieties; but the true anatomical history of the affection may be dated from 1803, when Scarpa published his memoir on the subject. In the simplest form, called talipes equi-nus, the heel is so raised that the person walks on the ball of the foot; this may vary from an elevation of an inch or two to a perfect continuation of the axis of the leg with that of the foot; it may be complicated with distortion inward or outward, and, in old cases, with permanent flexion of the leg on the thigh from contraction of the hamstring muscles. In talipes varus, which is the most common, the distortion is more complex; the heel is raised, the inner edge of the foot is drawn upward, and the whole foot is twisted inward, so that the person walks on the outer edge, and in extreme cases on the top of the foot and the outer ankle.

In this form the limb is small, the muscles of the calf being feebly developed; the toes arranged vertically, the great toe uppermost; the sole of the foot very concave, and the back very convex; the external ankle turned backward, and very near the ground, the internal high up and approaching the heel bone; a callus on the outer edge which corresponds to the sole. Walking is difficult and fatiguing, and the standing position insecure; when existing in both limbs, the feet must be constantly crossed over each other in walking; from the inward rotation of the limb the knee is turned outward, which increases the difficulty of standing and walking firmly. The joints are generally movable; the tendo Acliillis is tense, shortened, and turned inward with the heel. In new-born children the foot can be brought into the natural position, and in them varus is almost always combined with some degree of the first variety; indeed, the two are usually combined, giving a great number of intermediate forms. In talipes valgus the characters are the opposite of varus; the outer edge of the foot is raised up, and the person walks on the inner ankle and metatarsal bone of the great toe; the foot is strongly turned outward, as is the heel; the internal border is convex and the external concave; in this variety walking and standing are still more difficult and fatiguing.

An extreme degree of varus has been described by Duval, in which the dorsum or back of the foot touches the ground; in its first stage the foot rests on the dorsal surface of the great toe, the other toes being rolled inward toward the sole; in the second, the deviation begins further back, and the metatarsus is bent at a right angle toward the sole; and in the worst form the whole anterior part of the foot is turned back, the dorsum resting on the ground and the sole turned upward. This is usually congenital, and accompanied by deformity and stillness in the other joints of the limbs, and depends on contraction of the flexors of the toes and the muscles of the calf. A fifth form is described, in which the toes are turned upward, the dorsum of the foot approaching the anterior surface of the leg, and the person walking on the heel. Club-foot consists essentially in a contraction, rigidity, and atrophy of the muscles of the calf, the deformity taking place in whichever direction the muscular equilibrium is the most easily disturbed. - Various causes have been assigned for congenital club-foot, such as vicious positions of the foetus, and mental and physical affections of the maternal system, such as are generally supposed to cause arrests of development.

Convulsive diseases in infancy often cause permanent contraction of the muscles and consequent clubfoot. Before the time of Scarpa it was supposed that there was in club-foot a dislocation of the bones of the tarsus and metatarsus; he maintained that there was rather a torsion of the scaphoid, cuboid, and os calcis, which would carry with them in the same direction the rest of the foot. The deformity may depend on an abnormal conformation of the astragalus and cuboid bones, with deviation of the anterior bones, this being especially the case in congenital club-foot; and in some rare forms there may be dislocation of the astragalus, though in most cases this bone preserves its normal relations to the tibio-tarsal articulation. In varus, the scaphoid and cuboid and heel bones are rotated outward, and the ligaments which bind the last two are generally relaxed; in congenital cases all the bones are small and the muscles wasted, and the limb is cold and feeble, indicating imperfect nutrition and innervation; the tibialis anticus and posticus, the flexors of the toes, and the muscles of the calf, being stronger than the peroneal muscles, increase the torsion as age advances, and the tense tendo Achillis draws the tuberosity of the os calcis obliquely upward.

In talipes equinus the astragalus is more or less dislocated forward, and may be felt under the skin at the top of the instep; when the foot is rolled backward, the bones of the tarsus are more or less separated on their dorsal surface, and the joints below are proportionally approximated; the dorsal ligaments are thin and elongated, while those of the sole are shortened and thickened. In valgus, the deviations of the tarsal bones arc the opposites of those in varus. - In children the prognosis is more favorable than in adults, on account of the flexibility of the muscles and the suppleness of the joints. Until the latter part of the last century the only means employed for the treatment of club-foot were various kinds of bandages and apparatus for extension; these were inconvenient, painful, expensive, requiring years of trial, and useless except in the simplest cases and in early childhood. The indications for treating club-foot are fulfilled by the division of the tendo Achillis, or any other contracted tendon or tense fascia, and an apparatus for extending the foot at right angles with the leg.

The tendo Achillis had been for many years frequently divided in veterinary practice, but was not interfered with in man for the cure of club-foot until about the year 1782; though an acknowledged operation in surgery, it was not practised in France until 1816, when Delpech performed it with indifferent success; it had become almost forgotten when Stromeyer revived it in 1831; since that time the operation has become improved and simplified, and the apparatus for extension rendered efficient by Duval, Bouvier, Guerin, Roux, and the best surgeons of Europe and America. Tenotomy, as the operation is called, has been performed at all ages, from a few weeks to 50 years, and has been applied not only to the tendo Achillis, but to the flexors of the toes, the plantar fascia, and any of the tendons surrounding the ankle joint which seem to aid in producing the deformity. The operation is so simple, so free from pain, so easily performed, so little liable to unfavorable consequences, and generally so speedily efficacious, that it seems unpardonable, unless in a few exceptional cases, for a surgeon to submit his patient to the plaster moulds, starched bandages, and other immovable apparatus of the old method.

The divided tendon heals by a callus, which, when recent, may be extended to any desired length; the wasted antagonist muscles, being relieved from tension, gradually recover their power. At first the knife was passed under the tendon, piercing the skin largely on both sides of the limb, and extension was not applied until the fifth week, when the divided ends had contracted adhesions and lessened the chance of a favorable result. Stromeyer improved upon this by making a single puncture of small size, and by putting on the apparatus in the course of the second week. The tenotome is generally blunt-pointed, the skin being pierced by a lancet; it is introduced on the inner side of the limb, and is made to cut the tendon, previously put upon the stretch, from before backward, or toward the skin, without wounding the latter; this subcutaneous operation is painless, bloodless, and, from the exclusion of air from the wound, not liable to be followed by inflammation; extension should be applied as soon as it can be done, without causing too much pain.