Manual of Surgery Volume Second: Extremities—Head—Neck. Sixth Edition.

by Alexis Thomson; Alexander Miles

Treatment.—Under the age of six, and particularly in children, who are actively growing, the bones will probably straighten if the child is treated for rickets and kept off his feet; well-padded lateral splints are applied as recommended for knock-knee, and these should be taken off at intervals for massage and douching. Above the age of six, the choice lies between osteoclasis and osteotomy. In performing osteotomy the bone is either simply divided or a segment is resected. The fibula can usually be forcibly straightened, but may require to be divided through a separate incision. In aggravated cases it may also be necessary to lengthen the tendo Achillis.

The deformities of the bones of the leg in inherited syphilis, ostitis deformans, and osteomalacia have already been described.

Congenital Deficiencies of the Bones of the Leg.—The tibia may be absent completely or in part, more often on one side than on both sides. In either case the leg is short and stunted, the knee is flexed, the foot occupies the position of extreme equino-varus, and the limb is useless. The extent of the defects is demonstrated by the Röntgen rays. Among other defects with which it may be associated, absence or deficient development of the patella is the most frequent. When the upper end of the tibia is absent, the fibula articulates with the lateral condyle of the femur. The operative treatment aims at correcting the flexion at the knee, the equino-varus deformity of the foot, and at substituting the fibula for the absent tibia. The deficiency of the upper end may be compensated for by implanting the head of the fibula between the condyles of the femur, and that at the lower end by splitting the fibula so as to form a socket for the talus. Amputation should be avoided, as even a dwarfed leg and foot improves the service of an artificial limb. A modification of the O'Connor extension boot may be employed.

The fibula may be absent completely or in part. The clinical appearances depend upon the condition of the tibia. When the tibia is normal, the most notable feature is the absence of the lateral malleolus, and the extreme valgus attitude of the foot. More commonly the tibia makes a sharp forward bend just below its middle, and the overlying skin presents a dimple or scar-like depression. This has usually been regarded as an evidence of intra-uterine fracture, but the observations of Hoffa suggest that both the bend of the bone and the depression on the skin are due to pressure exercised upon the leg from without by an amniotic band or adhesion. The leg fails to grow, the deformity becomes more pronounced, and the toes become pointed. If the tibia is markedly bent, it may be straightened by osteotomy; and the tendons, Achillis and peronei, may require to be lengthened. If the ankle is unstable as a result of the absence of the lateral malleolus, it may be artificially ankylosed, or the lower end of the tibia may be split vertically so as to make a socket for the talus. In either case, the foot is placed in the equinus attitude to compensate for the shortening of the leg. Deficiency of the tibia is frequently associated with imperfect development of the great toe; deficiency of the fibula with absence of the lateral toes and their metatarsal bones.

Volkmann's Supra-malleolar Deformity.—This condition, which is closely allied to that just described, consists in a congenital deficiency in the development of the bones of the leg, and especially of the fibula, as a result of which the articular surface is oblique and the foot deviates to one or other side. The foot usually occupies a valgus position, the sole looking laterally, and only its medial border coming into contact with the ground. It is treated by supra-malleolar osteotomy.

The Foot

Various deformities are met with in the region of the ankle and tarsus. The term “talipes” is commonly used to include all these, but here it will be restricted to that form in which the heel is more or less elevated, and the foot supinated so that it rests on its lateral border—talipes equino-varus. In pes equinus the foot is in the position of plantar-flexion, and the patient walks on the toes. In pes calcaneus the foot is dorsiflexed so that the tip of the heel comes in contact with the ground; this deformity may be combined with eversion of the foot, pes calcaneo-valgus, or with inversion, pes calcaneo-varus. When the instep is unduly arched, the terms pes cavus, pes arcuatus or hollow claw-foot are employed; while loss of the arch constitutes flat-foot, and eversion of the sole, pes valgus.

Club-Foot

Talipes Equino-varus.—This deformity may be congenital or acquired.

Congenital talipes equino-varus ([Fig. 142]) is a common malformation which is sometimes associated with other deformities, such as hare-lip or spina bifida, and may be met with in several members of one family. It is nearly twice as common in boys as in girls, and is slightly more frequently bilateral than unilateral. Its etiology is obscure, and various hypotheses have been put forward to account for it, but no one is convincing. It may be pointed out, however, that the fœtal foot is very easily moulded into abnormal attitudes by external pressure such as might be exercised by the wall of the uterus when the liquor amnii is deficient. In a number of cases there are indications of such pressure over the bony prominences of the foot, in the shape of circumscribed scar-like areas in which the skin is atrophied; and in the infant, the intra-uterine position can be reproduced, thus demonstrating its method of origin. The occurrence of club-foot in several generations is alleged to support the Mendelian law.