Manual of Surgery Volume II Part 28

In _adolescent knock-knee_ the patient seeks advice because of the deformity or of pain after exertion, especially at the medial side of the epiphysial junctions, of being easily tired, and of incapacity for any occupation involving standing. The bones are coa.r.s.e and badly formed, and there is frequently a spinous process projecting downwards from the medial side of the tibia about three finger-breadths below the joint.

When the deformity is bilateral, the patient abducts the thigh and rotates the limb outwards at the hip to disguise the deformity, and to allow the projecting knees to pa.s.s each other. He usually supinates or inverts the foot, with the object of bringing the whole length of the lateral border of the sole into contact with the ground. Flat-foot is exceptional. The boots are usually more worn along the lateral than along the medial border of the sole and heel.

No apparatus that allows of the patient walking is of any value. If the deformity is marked, there should be no hesitation in having recourse to operation by one or other of the various methods of osteotomy.

In severe cases it may be found that when the deformity is corrected by osteotomy, the patella shows a tendency to be dislocated laterally on flexion of the knee. This may be prevented by putting up the limb in the att.i.tude of slight genu varum.

The most difficult cases to treat are those in which, owing to curving of the lower part of the shaft of the femur with the convexity forwards, the knee is permanently flexed and cannot be completely extended.

#Other forms of genu valgum# are relatively rare. There is a congenital form arising from faulty position of the limbs _in utero_; a traumatic form following fracture or epiphysial separation in the region of the knee; and a paralytic form, usually combined with flexion, in cases of spastic paralysis. Finally, genu valgum may be a result of various forms of osteomyelitis of the lower end of the femur, or of disease in the knee-joint, such as tuberculosis, arthritis deformans, or Charcot's disease.

#Genu Varum--Bow-knee.#--In this deformity, which is the converse of genu valgum, the leg joins the thigh at an angle which is open medially. It is almost invariably bilateral, is of rachitic origin, and is frequently a.s.sociated with bow-legs (Fig. 141). The tibia takes a greater share in its production than the femur. Although an ungainly deformity, it is much less frequently the source of complaint than knock-knee, because it scarcely interferes with locomotion--as a matter of fact, the subjects of bow-knee, although short in stature, are unusually st.u.r.dy on their legs. An extreme example of the deformity is shown in Fig. 141.

[Ill.u.s.tration: FIG. 141.--Bow-knee in Rickety Child.]

Treatment is carried out on the same lines as in genu valgum.

#Rickety Deformities of the Bones of the Leg--Bow-leg.#--These deformities are common in children; are nearly always bilateral and symmetrical, and may be a.s.sociated with knock-knee or bow-knee. They may occur before the child is able to walk, the bones bending in the att.i.tude in which the limbs are habitually placed--over the nurse's knee, for example, or as they are crossed underneath the child in sitting. In children who are able to walk, the curve is due to the weight of the body acting on the softened bones. In either case, the bending may be increased by the traction of muscles, and sometimes by the occurrence of greenstick fracture. The most common deformity is a uniform curvature of the bones laterally and forwards, or a more acute bend in the lower thirds of their shafts. In some cases the chief curvature is forwards. The ungainliness in walking may be added to by flat-foot. Backward curving of the upper end of the tibia has been already described as one of the causes of genu recurvatum. The most extreme deformities are met with in rickety dwarfs.

_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 ma.s.sage 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_, _ost.i.tis 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 Rontgen rays. Among other defects with which it may be a.s.sociated, 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 subst.i.tuting 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 att.i.tude 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 p.r.o.nounced, 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 att.i.tude to compensate for the shortening of the leg. Deficiency of the tibia is frequently a.s.sociated 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 const.i.tutes _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 a.s.sociated 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 ftal foot is very easily moulded into abnormal att.i.tudes 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 circ.u.mscribed 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.

[Ill.u.s.tration: FIG. 142.--Bilateral Congenital Club-foot in an infant.]

_Pathological Anatomy._--In well-marked cases the foot presents a concavity towards the medial side, the maximum point of the curve being opposite the mid-tarsal joint. When the patient attempts to stand, only the lateral border of the foot touches the ground, and the weight is borne on the fifth metatarsal, the cuboid, and the greater process of the calcaneus.

[Ill.u.s.tration: FIG. 143.--Radiogram of Bilateral Congenital Club-foot in an infant.]

The individual tarsal bones, especially the talus and calcaneus, are altered in shape as well as in their relations to one another and to the tibio-fibular socket. The navicular and cuboid are rotated medially around the anterior ends of the talus and calcaneus respectively, and the tubercle of the navicular comes to lie close to the medial malleolus. The lower third of the tibia is twisted medially on its vertical axis.

The changes in the soft parts follow the general law that tissues which are relaxed become shortened, while those that are put on the stretch are lengthened. All the tissues on the medial, concave side of the foot are shortened, the structures most affected being the medial and the posterior ligaments of the ankle, and the inferior calcaneo-navicular ligament. There is also shortening of the muscles inserted into the tendo Achillis, and to a less extent of the tibiales anterior and posterior. The extensor tendons on the dorsum are displaced medially.

_Clinical Features._--_In children who have not walked_, the degree of deformity varies, sometimes being very slight; in p.r.o.nounced cases, the foot is turned medially, and in that position forms a right angle with the leg; the sole looks backwards and the medial border upwards.

The foot appears shortened because it is curved on itself, the heel is narrower and more vertical than normal, the medial malleolus is obscured by the approximation of the navicular, and the lateral malleolus is unduly prominent.

In extreme cases, the supinated foot forms an acute angle with the leg, and there is frequently a deep transverse depression across the sole, the result of contraction of the plantar fascia--a feature which is distinctive of the congenital form of club-foot.

_In children who have walked_, the deformity becomes aggravated. The dorsum of the foot is markedly uneven, partly because of the prominence of the individual tarsal bones, and especially of the head of the talus and greater process of the calcaneus, and partly because of a depression over the neck of the talus. Instead of resting on its lateral border, the foot may finally rest on the dorsum, the sole looking upwards and backwards. While the skin over the heel remains comparatively thin and delicate, that covering the lateral border and dorsum of the foot becomes the seat of callosities, beneath which advent.i.tious bursae are formed. These bursae are liable to become inflamed, and are then a source of great suffering, and if they suppurate may cause persistent sinuses. The muscles of the leg and foot, although not paralysed, undergo atrophy from disuse. In walking, the patient lifts one foot over the other in an ungainly and laborious manner, without any spring, as if walking on stilts.

_In adults_, these features are further aggravated, and there are permanent changes in the bones (Fig. 144).

[Ill.u.s.tration: FIG. 144.--Congenital Talipes Equino-varus in a man aet.

24; seen from behind.]

_Treatment._--This should be commenced as soon as the viability of the infant is beyond question, as the younger the patient the more easily and completely is the deformity rectified. Manipulations to correct the deformity should be carried out twice or thrice daily, and the limbs are also ma.s.saged and douched. At the end of two or three months, a.s.sistance may be derived from the use of a simple lateral poroplastic or aluminium splint with a foot-piece, or more simply by a strip of rubber plaster. The foot is held in the over-corrected att.i.tude and the plaster is applied so as to maintain this att.i.tude.

If this regime is systematically persevered with from within a few days after birth, by the time the child begins to walk the sole can be brought into contact with the ground, and the weight of the body will aid in correcting the deformity. If the equinus element resists correction, the tendo Achillis should be lengthened.

The turning in of the toes may be overcome by strapping the feet at night to a wooden board with the whole lower limb rotated laterally so that the toes of each foot point directly outwards. On account of the tendency towards relapse, the manipulations and ma.s.sage must be persevered with for at least a year.

_Tenotomy and Forcible Correction under Anaesthesia._--In more severe cases we have to deal not only with the contracted soft parts, but with changes in the bones resulting from their having grown in adaptation to the deformed att.i.tude. The majority of surgeons defer operative measures until the child is about a year old.

The soft parts to be divided are the tendo Achillis, the medial and posterior ligaments of the ankle, the plantar fascia, the calcaneo-navicular ligaments, and the tibialis posterior tendon. The varus deformity may then be corrected by laying the foot on its lateral side on a padded triangular wooden block, and pressing forcibly on the anterior and posterior ends of the foot so as to undo the curve on its medial side and allow of abduction of the foot; this is usually attended with cracking as the shortened ligaments give way.

The equinus element is next dealt with by forcibly dorsiflexing the foot until the deformity is over-corrected. If it is preferred to correct the deformity in stages instead of at one sitting, the equinus element is left to the last. In older children, the strength of the hands is usually insufficient to stretch the tissues, and mechanical wrenches may be employed, such as those devised by Thomas, Bradford, or Lorenz.

_Resection of a wedge from the tarsus_ (Davies Colley, 1876) is reserved for the most severe cases in which the shape and rigidity of the bones prevent correction of the deformity by any other means. The base of the wedge is on the lateral aspect, and the bone removed includes parts of the calcaneus, cuboid, talus, and navicular.

_Removal of the talus_ is an alternative operation to resection of the tarsus, and may yield equally good results.

In children, before the tarsal bones have become completely ossified, Ogston's method yields good results; instead of removing a wedge from the tarsus, the osseous nucleus of each bone is gouged out, leaving the cartilaginous sh.e.l.l. In this way the intertarsal joints are not interfered with, and the cartilaginous tarsus can be moulded so that when ossification is completed the bones differ but little from the normal.

After any of these operative procedures, manipulations, ma.s.sage, exercises, electrical stimulation of the muscles, and the wearing of some apparatus must be persevered with for at least twelve months.

Failures are due to not sufficiently over-correcting the deformity in the first instance, and to neglect of after-treatment; in hospital practice it is difficult to ensure continuous supervision over long periods.

Finally, _amputation_ may be called for when other methods have failed, and the patient is unable to put the foot to the ground because of suppurating bursae and ulceration of the skin.

#Acquired Talipes Equino-varus.#--In the great majority of cases this condition results from anterior poliomyelitis. It especially affects the peronei and the extensors of the toes, and is unilateral. The patient is unable to dorsiflex and abduct the foot, which hangs with the toes pointed and the sole turned medially.

At first the joints are flaccid, and the att.i.tude can easily be corrected by manipulation. In course of time, however, the opposing muscles--those inserted into the tendo Achillis, the tibialis posterior, and the long flexors of the toes--become shortened, and there is secondary contraction of the plantar fascia and of the ligaments on the medial side of the foot, and the deformity is thus rendered permanent. The bones also are altered in their shape and mutual relations, the talus being rotated forwards so that a large portion of its trochlear surface protrudes from the tibio-fibular socket. The skin is cold and livid, and readily suffers from pressure sores. The whole limb is ill-developed, and may be shorter than its fellow, and the paralysed muscles are wasted and exhibit for a time the reaction of degeneration.

A similar deformity may result from section of the peroneal (external popliteal) nerve, from the peroneal form of progressive muscular atrophy, and from peripheral neuritis.

The _treatment_ of paralytic equino-varus, short of operation, has been referred to under anterior poliomyelitis (p. 242). If tendon transplantation is indicated, the tendon of the tibialis anterior is attached to the cuboid, and a strip of the tendo Achillis to the dorsal aspect of the tarsus. Jones displaces the tibialis anterior into the base of the fifth metatarsal.

If the paralysis is widely distributed, and the joints are flail-like, it is better to ankylose the ankle and mid-tarsal joints. It may be necessary to divide in several places the plantar fascia and other structures that have undergone secondary shortening.

As using the limb hastens the restoration of function, the child should be got on to his feet as soon as possible.