DEFORMITIES OF THE EXTREMITIES
The origin of deformities: (1) Those arising before birth; (2) those
produced during birth; and (3) those acquired after birth.
Palsies of children: _Anterior Poliomyelitis_. Cerebral palsies:
_Spastic paralysis_.
THE LOWER EXTREMITY: Congenital dislocation of hip--Snapping
hip--Paralytic deformities--Contracture and ankylosis of hip--Coxa
vara and coxa valga--Congenital dislocation of knee and
patella--Genu recurvatum--Paralytic deformities--Contracture and
ankylosis of knee--Genu valgum and genu varum--Congenital
deformities of leg--Bow-leg--Club-foot: _Talipes equino-varus_;
_Pes equinus_; _Pes calcaneus_; _Pes calcaneo-valgus and varus_;
_Pes cavus_; Flat-foot and pes valgus--Painful affections of
heel--Metatarsalgia--Hallux valgus and bunion--Hallux
varus--Hallux rigidus and flexus--Hammer-toe--Hypertrophy of
toes--Supernumerary toes--Webbed toes.
THE UPPER EXTREMITY: Congenital absence of clavicle--Elevation of
scapula--Winged scapula--Congenital paralytic deformities of
shoulder--Deformities of elbow--Club-hand--Deformities of
wrist--Madelung's deformity--Deformities of fingers--Dupuytren's
contraction--Polydactylism.
The surgery of the extremities is so largely concerned with the
correction of deformities that it is necessary at the outset to refer
briefly to some points relating to the time and mode of origin of
these.
1. _Congenital deformities_--that is, those which originate _in utero_
and are present at birth--are comparatively common and may be due to a
variety of causes. Some result from errors of development--for
example, supernumerary fingers or toes, and deficiencies in the bones
of the leg or forearm. A larger number are to be attributed to a
persistent abnormal attitude of the foetus, usually associated with
want of room in the uterus--for example, the common form of club-foot
and congenital dislocation of the hip. Less frequently amniotic bands
so constrict the digits or the limbs as to produce distortion, or even
to sever the distal part--_intra-uterine amputation_. Lastly, certain
diseases of the foetus, and particularly such as affect the
skeleton--for example, achondroplasia--cause congenital deformities.
2. _Deformities originating during birth_ are all traceable to the
effects of injuries sustained in the course of a difficult labour.
Examples of these are: wry-neck resulting from rupture of the
sterno-mastoid; lesions of the shoulder-joint and brachial plexus due
to hyper-extension of the arm; a spastic condition of the lower
limbs--Little's disease--resulting from tearing of blood vessels on
the surface of the brain with haemorrhage and interference with the
function of the cortical motor area.
3. _Deformities acquired after birth_ arise from widely different
causes, of which diseases of bone, including rickets, diseases of
joints, and affections of the nervous system attended with paralysis,
are amongst the commonest. Other deformities are produced by
unsuitable clothing, such as a tight corset, or ill-fitting shoes
distorting the toes, prolonged standing in growing subjects
overstraining the mechanism of the foot and giving rise to the common
form of flat-foot.
The part played by the palsies of children in the surgical affections
of the extremities necessitates a short description of their more
important features.
#Anterior poliomyelitis# is the lesion underlying what was formerly
known as _infantile paralysis_--a name to be avoided, because the
condition is not confined to infants and it is not the only form of
paralysis met with in young children. Anterior poliomyelitis is
characterised by an illness attended with fever, in which the child is
found to have lost the power of one, less frequently of both lower
extremities; or, it may be, of one or both arms. After a period,
varying from six weeks to three months, the paralysis tends to
diminish both in extent and degree, and in the majority of cases it
ultimately persists only in certain muscles or groups of muscles. At
the onset of the paralysis the affected limb is helpless and relaxed,
the reflexes are lost, the muscles waste, and those that are paralysed
exhibit the reaction of degeneration. In severe cases, and especially
if proper treatment is neglected, the nutrition of the limb is
profoundly affected; its temperature is subnormal, the skin is bluish
in cold weather and readily becomes the seat of pressure sores. In
course of time the limb lags behind its fellow in growth, and tends to
assume a deformed attitude, which at first can easily be corrected,
but later becomes permanent.
[Illustration: FIG. 127.--Female child showing the results of
Poliomyelitis affecting the left lower extremity; the limb is short
and poorly developed, the pelvis is tilted and the spine is curved.]
When the acute stage of the illness is past, the chief question is to
what extent recovery of function can be looked for in the paralysed
muscles.
It would appear to be established that if a muscle reacts to faradism
it will recover, but the contrary proposition does not follow. It was
formerly accepted that a muscle which exhibits the reaction of
degeneration is incapable of recovery, but observation has shown that
this is not the case. Complete destruction of the motor cells in the
anterior horn of grey matter as a result of poliomyelitis is now known
to be exceptional; as a matter of fact, damage to the nerve cells is
usually capable of being repaired. The muscles governed by these cells
may appear to be completely paralysed, but with appropriate treatment
their functional activity can be restored. As functional disability is
frequently due to the affected muscle being _over-stretched_, it is of
the first importance, when the acute symptoms are on the wane, that
every care should be taken to prevent the weak muscular groups being
put upon the stretch, and the greatest attention should be paid to
_the posture of the limb during convalescence_. For example, if the
child is allowed to lie with the wrist flexed, the flexor muscles
undergo shortening, and the extensors are over-stretched and are
therefore placed at a mechanical disadvantage. As the inflammatory
changes in the anterior horn of the cord subside, the flexor tendons,
from their position of advantage, are in a condition to respond to the
first stimuli that come from their recovering motor cells, while the
extensors are not in a position to do so. If, on the other hand, the
wrist and fingers are maintained in the attitude of extreme
dorsiflexion, the extensors become shortened, and, relieved of strain,
they soon begin to respond to the stimuli sent them from the
recovering nerve cells. Similarly in the lower extremity, when, for
example, the muscles innervated through the peroneal (external
popliteal) nerve are paralysed, if the foot is allowed to remain in
the attitude of inversion with the heel drawn up--paralytic
equino-varus--an attitude which is rendered more pronounced by the
pressure of the bedclothes, the chance of the muscles recovering their
function is seriously diminished. Another potent factor in preventing
recovery, especially in the lower limbs, is _erroneous deflection of
the body weight_. If, for example, there is weakness in the tibial
group of muscles, and the child is allowed to walk, the eversion of
the foot will steadily increase, the tibial muscles will be more and
more stretched, the opposing peroneal muscles will shorten, and, in
time, the bones of the tarsus will undergo structural alterations
which will perpetuate the deformity. If, on the other hand, by some
alteration of the boot, the foot is maintained in the attitude of
inversion, the weakened or paralysed tibial muscles are placed in a
much more favourable condition for recovery.
It must be emphasised that no operation should be performed in these
cases until the question whether it be possible or not to restore the
apparently paralysed muscle is settled. The clinical test of the
recoverability of a muscle is to keep it for a long period--six or
even twelve months--in a condition of relaxation. This test should be
made, no matter how many months or years the muscle may have been
paralysed.
The first stage in the treatment, therefore, is the correction of
existing deformity, after which the limb should be kept immovable
until the ligaments, muscles, and even the bones have regained their
normal length and shape. The slightest stretching of a muscle which is
in process of recovery disables it again.
The age of the patient influences the method of treatment. In young
children in whom the structures are soft and yielding, gradual
correction of the deformity is to be preferred to the more rapid
methods employed in older children. The proper sequence consists in
correcting the deformity, providing the simplest apparatus to keep the
limb in good position, preventing erroneous deflection of body weight
during walking, and then allowing the child to grow and develop until
he has reached the age of five before considering such an operation as
transplanting tendons, and the age of ten before deciding to ankylose
a flail-like joint.
_Reposition, Manipulations, Supports._--An attempt is made to correct
the deformity by manipulation, and the proper attitude is maintained
by a mechanical support. If the foot has become rotated so that the
sole looks laterally, the medial side of the boot must be raised, and
an iron worn which extends from the knee down the lateral side of the
leg, to end, without a joint, in the heel of the boot. In pes equinus,
the iron is let into the back of the heel and extends forwards into
the waist of the boot, to keep the foot at right angles to the leg and
to relax the weak extensor muscles.
_Division of Contractions._--Bands of fascia and contracted tendons
which prevent correction of deformity may have to be divided or
lengthened. This is best done by the open method.
_Removal of Skin._--To assist in maintaining the desired attitude,
Jones recommends the plan of excising an area of the redundant skin on
the weaker aspect of the limb; in equinus, the skin is taken from the
dorsum; in equino-varus, from the front and lateral aspect of the
foot. When the edges of the gap have united, the foot is maintained in
the desired attitude for some months, even if parents carelessly
remove the iron support to let the child run about.
_Tendon transplantation_, a procedure introduced by Nicoladoni, is to
be considered in children of five and upwards. It may be employed for
different purposes: (1) To reinforce a weak muscle by a healthy
one--for example, by transplanting a hamstring tendon into the patella
to reinforce a weak quadriceps, or reinforcing the weak invertors of
the foot by a transplanted extensor hallucis longus. (2)
Transplantation may also be performed to replace a muscle which is
quite inactive and does not show any sign of recovery--for example,
the tibiales being paralysed, the peroneus longus may be implanted
into the navicular or first metatarsal to act as an invertor of the
foot.
Wherever possible a tendon should be transplanted directly into bone,
as, if it is attached to soft parts it rarely holds firmly enough. The
bone should if possible be tunnelled, and the tendon passed through
the tunnel and securely fixed. When bringing a tendon to its new point
of attachment, it should pass in as straight a line as possible,
avoiding any bend or angle which might impair its action. Fat is the
best medium for the transplanted tendon to traverse, as it acts as a
sheath and prevents the formation of adhesions which would interfere
with the function of the new tendon. All deformity must be corrected
before transferring the tendon; if the tendon is too short to admit of
this, it can be lengthened by means of silk threads (Lange).
According to Jones, the most successful transplantations are the
following, in order: (1) The tibialis anterior into the lateral tarsus
in paralysis of the peronei; (2) the peroneus longus into the
navicular in paralysis of the tibial group; (3) the extensor hallucis
longus into any part of the foot where it may be wanted; (4) the
hamstrings into the patella, to reinforce the quadriceps, provided the
strictest after-treatment can be secured; (5) deflection of part of
the tendo Achillis to one or other side of the foot.
_Arthrodesis._--This operation, first performed by Albert in 1877,
consists in removing the cartilage covering the articular surfaces of
bones with the object of producing a firm ankylosis. The procedure is
most successful in the ankle and mid-tarsal joints, and as a result of
it there is obtained a secure and firm base of support in walking.
Before performing arthrodesis, the surgeon must decide whether the
patient will be better off with a stiff joint or with a weak and
movable ankle supported by apparatus. This is often a matter of social
position; in the poor, an ankylosed joint is more useful and less
expensive. An arthrodesis should seldom be performed at the ankle
until the child has passed his eighth year, or at the knee until he
has reached his twentieth year. There is plenty to be done during the
period of waiting, and if this is done well, it is possible that the
operation may not be required. The existing deformities, for example,
will have to be corrected, areas of skin removed to relieve
functionless muscles of strain, the body weight appropriately
deflected, and the child must be taught to walk with the aid of a
support, swinging his limb about, and using it effectively in a
correct position. Such exercise is a powerful agent in promoting
physiological and functional development.
_Nerve anastomosis_, which seeks to provide a new channel for the
transmission of motor impulses to the paralysed muscles, has as yet a
restricted field of application--for example, the tibial and peroneal
nerves may be anastomosed when the muscles supplied by one of them are
paralysed. Stoffel of Heidelberg lays stress on regard being paid to
the anatomical arrangement of the nerve bundles within the nerve-trunk
so that motor fibres may be joined to motor ones and not to sensory.
It is necessary also to cut across some of the fibres of the healthy
nerve in order that they may grow into the nerve which is degenerated.
In extreme cases in which the limb is hopelessly paralysed and
useless, it may be _amputated_ to admit of an artificial limb being
worn; it must be borne in mind, however, that such limbs furnish poor
stumps, usually quite unable to bear pressure.
#Cerebral Palsies of Childhood--Spastic Paralysis.#--These may be due
to arrest of development of the brain, to injuries of the head at
birth, to meningeal haemorrhage, or to other lesions of the brain, with
secondary degenerative changes in the spinal cord. The commonest cause
is haemorrhage occurring during child-birth from the veins which ascend
from the middle part of the convexity of the hemisphere to open into
the superior sagittal (superior longitudinal) sinus. The blood is
poured out beneath the dura on one or on both sides of the falx
cerebri, and as it accumulates near the vertex, the damage to the
motor centres for the legs is usually more extensive than that to the
centres for the arms. The paralysis may affect one side of the
body--_hemiplegia_, or both sides--_diplegia_; less commonly one
extremity alone is involved--_monoplegia_. In diplegia, in which both
arms and both legs are affected in the first instance, the arms may
recover while the lower extremities remain in a spastic state, a
condition known as _Little's disease_. The mental functions may be
normal but more frequently they are imperfectly developed, the
impairment in some cases amounting to idiocy. The affected limbs
exhibit muscular rigidity or spasm, which is aggravated on movement
but disappears under an anaesthetic; the reflexes are exaggerated, and
sometimes there are perverted involuntary movements (_athetosis_). The
growth of the limb is impaired, and contracture deformities may
supervene (Fig. 131). The amount of power in the limb is often
astonishing, in marked contrast to what is observed to follow upon
anterior poliomyelitis. The degree of natural improvement is by no
means great, and normal function is almost never regained.
The _treatment_ is concerned in the first place with improving the
condition of the muscles by methodical exercises and massage. When
reflex irritability of the muscles with consequent spasm is a
prominent feature, the reflex arc may be interrupted by _resection of
the posterior nerve roots_ corresponding to the part affected. This
operation, first suggested by Spiller but chiefly popularised by
Foerster, has yielded the best results in cases of Little's disease,
in which there still remains a considerable amount of voluntary
movement, and yet there is inability to walk on account of involuntary
spasm. In the case of the lower extremities, three or more of the
lumbar and one or more of the sacral nerve roots are resected within
the vertebral canal. Sensation is diminished but not abolished in the
area of skin involved. Massage and exercises and, it may be, splints
or apparatus are essential factors in promoting the recovery of
function. It has not yet been decided whether the results of the
resection of nerve roots justify the risk.
Apart from Foerster's operation, or when it has failed, the spasm of
any individual muscle or group of muscles may be got rid of by
diminishing the nerve supply to the muscle or by lengthening the
tendon. Diminishing the nerve supply was suggested by Stoffel; it
consists in exposing the motor nerve as it enters the muscle and
resecting one-third or one-half of the fibres so as to reduce the
innervation to the required degree. The method is still on its trial.
_Lengthening the Tendons._--In spastic paraplegia, for example, Jones
resects the origins of the adductors longus and brevis, lengthens the
tendo Achillis, divides the popliteal fascia and hamstrings, and
transplants the biceps into the quadriceps; after which the limbs are
put up in the attitude of wide abduction for six weeks. It is
important that the patient should begin to walk with the legs wide
apart and learn to balance himself without any feeling of insecurity;
he should be taught to look at an object straight in front of him
rather than on the ground.
THE LOWER EXTREMITY
CONGENITAL DISLOCATION OF THE HIP
This is the commonest of all congenital dislocations. Its frequency
varies in different countries, being greater on the continent of
Europe than in this country. It is more often unilateral than
bilateral (about 4 to 1), and is about three times more common in
girls than in boys.
The dislocation takes place in the early months of intra-uterine life,
and may be associated with deficiency of the liquor amnii.
#Pathological Anatomy.#--_In the infant_, the anatomical changes in
the joint are less marked than they are after the child has borne its
weight on the limb. The acetabulum, never having been occupied by the
head of the femur, is imperfectly developed; it remains flat and
shallow, is partly filled with fibro-fatty tissue derived from the
synovial membrane, and is always too small for the head of the femur.
The cotyloid ligament being broader and thicker than usual, makes the
osseous portion of the socket appear deeper than it really is. In
unilateral cases the affected half of the pelvis is contracted, so
that the pelvic basin is narrowed and oblique. The head of the femur
is small, flattened, and, in some cases, conical; and the angle formed
by the neck with the shaft is altered, sometimes diminished, it may be
to a right angle--_coxa vara_ (Fig. 129); sometimes increased--_coxa
valga_. There is also a variable degree of torsion of the neck,
ante-torsion being of practical importance as it increases the
difficulty of retaining the head in the socket. The capsule is lax and
admits of the head passing upwards for a variable distance on to the
dorsum ilii. In unilateral cases the ligamentum teres is elongated and
thickened; in bilateral cases it is frequently absent.
[Illustration: FIG. 128.--Radiogram of Double Congenital Dislocation
of Hip in a girl aet. 4.]
[Illustration: FIG. 129.--Innominate Bone and upper end of Femur from
a case of Congenital Dislocation of Hip.]
In _children who have walked_, the head of the femur is pushed farther
upwards on the dorsum ilii; the capsule becomes lengthened by
supporting the weight of the body. That part of the capsule which
arises from the lower margin of the acetabulum stretches across the
socket and partly shuts it off from the rest of the joint cavity. In
course of time the capsule becomes greatly thickened, and may present
an hour-glass constriction about its middle, which may prove a serious
obstacle to reduction. The socket becomes small and triangular, and
there is almost no ledge against which the head of the femur can rest.
A superficial depression may form on the ilium where it is pressed
upon by the head of the femur, covered by the capsule; and in the
course of years, as the head changes its position, several secondary
sockets may be formed. No proper new bony socket forms like that in
traumatic dislocations that remain unreduced because in the congenital
variety the thickened capsule intervenes between the head of the bone
and the dorsum ilii. The displacement of the head is most frequently
backwards (dorsal luxation), and as the point of support thus falls
behind the acetabulum the pelvis tilts forwards, and the lumbar spine
becomes unduly concave (lordosis). The muscles of the hip and thigh
alter in consequence of the changed relations; the gemelli,
obturators, and piriformis are lengthened, the adductors, hamstrings,
and ilio-psoas are shortened, while the glutei and quadriceps are but
little altered. In rare cases the head is displaced upwards and lies
immediately above the acetabulum.
[Illustration: FIG. 130.--Congenital Dislocation of Left Hip in a girl
aet. 8. The patient is putting the whole weight on the dislocated
limb.]
_Clinical Features._--The condition rarely attracts attention until
the child begins to walk, but sometimes the unusual breadth of the
pelvis, the presence of a lump in the buttock, snapping about the hip,
or a peculiar way of holding the limb, leads the parents to seek
advice early. In _unilateral cases_, when the child has learned to
walk at the late age of two, three, or it may even be four years, it
is noticed that the back is hollow and the buttocks unduly prominent,
and that there is a peculiar and characteristic limp; each time the
weight of the body is put upon the affected limb, the trunk makes a
sudden dip towards that side. There is no pain on walking. The
affected limb is shortened, as is shown by the projection of the great
trochanter above Nelaton's line; the shortening gradually increases,
and in time may amount to several inches. It is partly compensated for
by resting the affected limb on the balls of the toes and flexing the
knee on the sound side. The gluteal fold is shorter, deeper, and
higher than on the healthy side, and on account of the obliquity of
the pelvis the spine shows a lateral curvature, with its concavity to
the affected side. The movements at the hip-joint are free in all
directions except abduction; on practising external rotation it is
often found to be abnormally free; lastly, in young children, if the
pelvis is fixed, the head of the bone may be made to glide up and down
on the ilium.
_In bilateral cases_ the trunk appears well grown in contrast to the
short lower limbs, the hollow of the back is exaggerated, the abdomen
protrudes, the perineum is broadened, and the buttocks are unduly
prominent. The gait is waddling like that of a duck, the trunk
lurching from one side to the other with each step. In untreated cases
the deformity and disability become more pronounced as the capsular
and round ligaments are further stretched, the shortening and limp
become more marked, the patient is easily fatigued by walking or
standing, and is usually unfitted for earning a living. We have had
under observation, however, an adult male with bilateral dislocation
and extroversion of the bladder, who efficiently performed the duties
of a carrier for many years.
Except in fat infants, the _diagnosis_ is not difficult; the absence
of pain and tenderness, the freedom of motion and the absence of the
head of the femur from its normal position, differentiate the
condition from tuberculous disease of the joint, and from coxa vara
and other deformities in the region of the hip. _Trendelenburg's test_
consists in noting the relative level of the buttocks when the patient
stands on the affected leg. Normally the buttocks remain on the same
level when the patient stands on one leg; in congenital dislocation
the buttock of the limb raised from the ground drops to a lower level;
in coxa vara it rises higher.
In paralytic conditions at the hip there may be considerable
resemblance to dislocation, but the muscles are slack and wasted, and
the normal attitude can easily be restored by pulling on the limb. The
most certain means of diagnosis is by the X-rays, which show the
position of the head of the bone in relation to the acetabulum, and
any torsion of the neck of the femur that may be present. This last
point is determined by taking a series of skiagrams in different
positions of the limb; these are also useful in correcting erroneous
impressions as to the angle of the neck of the femur.
_Treatment._--We are indebted to Paci, Schede, Calot, Lorenz, and
Hoffa for the rational treatment which seeks to reduce the dislocation
by manipulation.
#Reduction by Manipulation# (_Method of Lorenz_).--The child is
anaesthetised and placed on its back with the legs over the end of the
table. While an assistant steadies the pelvis, the surgeon pulls on
the limb so as to bring the trochanter down to Nelaton's line; this is
followed by forced rotation outwards and inwards and forcible
abduction to a right angle, and by kneading the adductors till they
are stretched and torn. The next step is to stretch the hamstrings,
and this is done by raising the foot, without bending the knee, until
the front of the thigh meets the abdomen, and the toes the face. To
stretch the anterior muscles, the patient is turned on the side or
face, and the hip is hyper-extended both in the straight and in the
abducted position. The stage is now reached at which attempts at
reduction may be made; the child is again laid on its back, the
surgeon grasps the knee, flexes the thigh to a right angle, rotates
laterally, and slowly flexes and abducts, while the thumb pushes from
behind on the trochanter, trying to guide and lift it over the rim of
the socket as the hip reaches the over-abducted position. Lorenz uses
a wedge of wood padded with leather about 3 inches high to rest the
trochanter upon while attempting to lift it forward. When reduction
takes place, there is generally a sound and a sudden jump, as in
reducing a traumatic dislocation.
To keep the head in the socket, the limb must be maintained in the
position of right-angled abduction and external rotation (90 deg.) by a
plaster case, which includes the lower part of the trunk and both
limbs down to the knee. Under the plaster, stockinette drawers are
worn, and the bony prominences are padded with cotton wool. The
plaster should overlap the costal margin. The first case is worn for
two months or more, and is then renewed at shorter intervals, the
degree of abduction being diminished at each renewal until the limbs
are nearly parallel. The child is only kept in bed for a week or two,
and is then allowed up, being provided with a boot and high sole on
the affected side, but should not use crutches. At the end of six
months, by which time the capsule has become tightened up round the
head of the femur, the plaster is given up and massage and exercises
are employed.
_In bilateral cases_ both dislocations are reduced at one sitting if
possible, and a plaster case applied with both thighs abducted and
flexed to a right angle, the so-called "frog position."
In the event of failure to reduce a dislocation at the first attempt,
the limb should be fixed in plaster in the abducted attitude for ten
days or a fortnight, and then another attempt made. The greatest
number of successes in bilateral cases is met with under five years of
age, and in unilateral cases under seven. Reduction may sometimes be
accomplished, however, in older children.
If it is found impossible to restore the head of the femur to the
acetabulum, an attempt should be made by similar manipulations to
wedge it under the long head of the rectus femoris, or, failing this,
below the anterior iliac spine under the sartorius and tensor fasciae
femoris. By thus converting a posterior into an anterior dislocation,
the tilting of the pelvis and the lordosis are greatly diminished.
This procedure, named by Lorenz _anterior transposition of the head of
the femur_, is specially applicable to cases in which relapse has
taken place after reduction, and to those above the age when reduction
should be attempted.
_Reduction by open operation_ may be had recourse to in cases in
which, after several attempts, reduction has failed, or in which
re-dislocation has occurred; it is, however, a serious operation.
Attempts have also been made by means of pegs and other contrivances
to fix the head of the bone and prevent it sliding upwards on the
ilium. When reduction is impossible by any means, a stiff leather
jacket with prolongations around the thighs may diminish the deformity
and improve the walking.
#Snapping Hip# (_Hanche a ressort_).--This is a rare affection, met
with in children and young adults, and characterised by the occurrence
of a sudden, snapping sound, sometimes attended with pain in the
region of the great trochanter. This usually occurs when the limb is
slightly flexed or adducted, and rotated either inwards or outwards.
On palpation a cord-like structure may be felt, which slips forwards
and backwards over the trochanter when the position of the limb is
altered.
The condition was formerly described as a voluntary dislocation of the
hip; it is now believed to be due to a cord-like band of tissue
slipping backwards and forwards over the trochanter. The band is
usually derived from the fascia lata, sometimes reinforced by the
anterior fibres of the gluteus maximus, sometimes by the tensor fasciae
femoris. The condition seldom gives rise to any appreciable disability
and surgical treatment is rarely called for. In a number of cases the
muscle has been fixed by sutures with satisfactory results. In a
recent case, an extensive open dissection proved negative, but the
stitching of the gluteus to the trochanter was followed by the
disappearance of the snapping.
#Paralytic Deformities of the Hip.#--In anterior poliomyelitis the
paralysis of muscles may be so widespread that the limb is unable to
support the weight of the body, or certain groups of muscles only are
paralysed and the child may be able to walk with the help of
apparatus. Even if the ilio-psoas is paralysed, flexion is still
possible by the anterior fibres of the gluteus medius, the anterior
adductors, and when the leg is rotated out by the tensor fasciae and
sartorius, the dislocation differs from the traumatic variety in that
the head, although it leaves the socket, remains within the capsule.
Dislocation tends to occur from the disturbance of muscular balance,
anterior dislocation being commoner than posterior in about the
proportion of two to one; the nature of the dislocation is best
demonstrated by means of the X-rays. Reduction is rarely possible
without an open operation. Tendon and nerve-transplantation are
scarcely possible, and arthrodesis is rarely to be recommended;
contracture deformities, however, are often benefited by tenotomy in
young children, and in older children by osteotomy through the
trochanter, and putting the limb up in the abducted position.
In _spastic paralysis_ of cerebral origin, the tendency is towards
contracture, usually in the attitude of flexion, with adduction and
inversion. This may result in dislocation backwards on to the dorsum
ilii, and may occur in patients confined to bed (Fig. 131).
[Illustration: FIG. 131.--Contracture Deformities of Upper and Lower
Limbs resulting from Spastic Cerebral Palsy in infancy.
(Photograph taken after death by Dr. Thomson of Norwich.)]
#Contractures and Ankyloses of the Hip.#--Various forms of contracture
are met with as a result of cicatricial contraction, or from
shortening of the fasciae, muscles, and ligaments when the hip has been
maintained in the flexed position for long periods--for example, in
psoas abscess, chronic rheumatism, or hysteria. The majority, however,
result from tuberculous disease of the hip-joint. In osseous
ankylosis, an attempt may be made to restore movement by the operation
of Murphy, which consists in chiselling through the osseous junction
between the bones, deepening the acetabulum if necessary, and then
interposing between the bony surfaces a portion of fat-bearing fascia
derived from the fascia lata over the great trochanter. The operation
of Jones consists in detaching the great trochanter (the insertions of
the glutei into it being left intact), dividing the neck of the femur,
and then securing the separated portion of the trochanter to the
proximal end of the neck to prevent union of the fragments.
COXA VARA AND COXA VALGA
These deformities depend on abnormalities of the angle of the neck of
the femur; the average or normal elevation is 125 deg. for the adult and
135 deg. for the child; variations between 120 deg. and 140 deg. are considered
normal. If the angle is less than 120 deg. the condition is one of coxa
vara; if greater than 140 deg., coxa valga. The angle of inclination of
the neck of the femur is dependent upon the adjustment of certain
forces, namely, the weight of the body, the action of muscles, and the
resistance of the bone. The most obvious cause of deviation of the
neck from the normal angle is some condition which causes softening
of the bone so that it yields under weight-pressure, the most common
being partial fractures, rickets, and other diseases of the bone.
#Coxa Vara--Incurvation of the Neck of the Femur.#--There may be a
simple adduction bend of the neck, the head sinking to, or even below,
the level of the great trochanter (Fig. 132); or this may be combined
with a curve of the neck, of which the convexity is upwards and
forwards, so that the lower border of the neck is greatly shortened
and the head approximated to the lesser trochanter. At the same time
the shaft of the femur is adducted and rotated outwards.
[Illustration: FIG. 132.--Rachitic Coxa Vara.
(Sir Robert Jones' case. Radiogram by Dr. Morgan.)]
_Adolescent Coxa Vara._--This, the most common clinical type, is met
with in boys between the ages of twelve and eighteen. The _unilateral_
form is nearly always the result of injury to the neck of the femur or
to the epiphysial junction, although the deformity may not show itself
for months or a year or two after the injury. The deformity may be the
first indication, or it is preceded by pain and stiffness; the patient
complains of being easily tired, of difficulty in kneeling and
sitting, difficulty in riding, and of an increasing limp in walking.
On examination, the limb is found to be shortened, the great
trochanter is displaced upwards and backwards and is unduly prominent,
and the muscles of the buttock and thigh are a little smaller and
softer than on the normal side. The limb is adducted, its normal range
of abduction, and sometimes also of flexion, is restricted, and there
is, as a rule, some degree of lateral rotation, so that the toes point
outwards. It should be noted that the same picture--shortening with
eversion and stiffness at the hip--results from the common fracture of
the neck of the bone in old people. The adduction element of the
deformity is partly compensated for by upward tilting of the pelvis on
the affected side and curvature of the spine with its concavity
towards the affected limb.
_When the condition is bilateral_ it is usually the result of disease
in the bone, rickets most frequently in this country. The attitude and
gait are highly characteristic, as the adducted and everted legs tend
to cross each other at the knee, the deformity being of the
scissors-like type (Fig. 134), and in extreme cases the patient is
only able to walk with the aid of crutches.
_Diagnosis._--Pain in the hip and a limp in walking suggest _hip-joint
disease_, but while in coxa vara the movements are chiefly restricted
in the direction of abduction, in hip disease they are restricted or
absent in all directions. From _congenital dislocation of the hip_
the diagnosis can usually be made by the history, the examination of
the joint and of its movements; and by the Trendelenburg test (p.
252). In _sacro-iliac disease_, the pain and tenderness are over the
sacro-iliac joint and the movements at the hip are free in all
directions. Valuable evidence is obtained from skiagrams.
_Treatment._--In the early stages, especially if there is pain and
tenderness, the patient must lie up and extension is applied in the
abducted position of the limb; after a fortnight or so recourse is had
to massage and exercises and the patient is allowed up for a little
each day, attention being paid to flat-foot, which is a common
accompaniment. When deformity is the prominent feature and interferes
with locomotion it must be corrected. The bloodless method is to be
preferred; under general anaesthesia, the shortened adductors are
stretched or divided, and forcible movements are carried out in all
directions, until the limb can be brought into an attitude of marked
abduction and internal rotation. A plaster-case is then applied, from
the pelvis to the middle of the calf, the knee being slightly flexed
for greater comfort; in a week or so the patient is able to go about,
and in a couple of months a second plaster-case is applied, this time
leaving the knee free. After another six weeks or so a moulded splint
is used, which can be removed at bedtime. The traumatic forms can
nearly always be corrected by this bloodless method. In advanced cases
the deformity can only be corrected by open operation, which consists
in dividing the femur obliquely downwards and medially through the
great trochanter, and, the adductor muscles having been ruptured or
divided, the limb is put up in the abducted position along with, if
required, powerful weight extension.
[Illustration: FIG. 133.--Coxa Vara, showing adduction curvature of
neck of femur associated with arthritis of the hip and knee.]
[Illustration: FIG. 134.--Bilateral Coxa Vara, showing scissors-leg
deformity.]
In cases of traumatic origin--epiphysial separation--Sprengel has
obtained good results by forcibly abducting and internally rotating
the limb under an anaesthetic, and then applying a plaster-case which
extends down to the knee.
#Other Forms of Coxa Vara.#--In _rickety children_, coxa vara is most
often associated with pronounced eversion of both lower extremities,
without the capacity for abduction being necessarily restricted, and
with but little impairment of function. The child should be treated
for rickets, and put up in a double long splint with the limbs
abducted and inverted.
In _arthritis deformans_ of the hip, it is not uncommon to have
considerable depression of the head of the bone and diminution in the
angle of its neck, with consequent restriction of abduction. Sometimes
the upper end of the shaft is also curved.
In _osteomyelitis fibrosa_, involving the upper end of the femur, a
gross form of coxa vara may be observed, of which a marked example is
shown in figures on pp. 476, 478, Volume I.
The _congenital variety_ of coxa vara is due to various intra-uterine
conditions, of which the chief is defective development of the upper
end of the femur; as it does not manifest itself until the child
begins to walk, the resemblance to congenital dislocation of the hip
is very close.
#Coxa Valga.#--Coxa valga is the reverse of coxa vara, the angle at
the neck of the femur being over 140 deg.. It is not nearly so important
in practice as coxa vara. It may result from incomplete fractures or
epiphysial separations, rickets, or various forms of osteomyelitis,
but it is also a frequent accompaniment of other deformities, such as
congenital dislocation of the hip and paralysis following anterior
poliomyelitis. It is commoner in boys than in girls, and is more often
single than bilateral. The limb is lengthened, abducted, and rotated
outwards; there is flattening of the buttock, and the trochanter is
depressed so that it lies below Nelaton's line. The patient is unable
to adduct the limb, and shows a peculiar gait, which has frequently
caused the condition to be mistaken for unilateral congenital
dislocation at the hip.
In recent cases it may be possible under anaesthesia forcibly to adduct
the limb and rotate it inwards, and to retain it in this position with
a plaster bandage. In advanced cases the length of the limbs may be
equalised by a high sole on the sound side, or by performing an
osteotomy through the great trochanter.
THE REGION OF THE KNEE
#Congenital dislocation# at the knee-joint is rare; it is usually
incomplete, and the patella is sometimes absent. The dislocation may
be permanent, or may only occur from accidental movements of the limb.
In some cases it can be produced at will by the patient or the
surgeon. We have observed one such case in a professional cyclist in
whom this capacity of partially dislocating the knee entailed no
disability. When the child begins to walk, an apparatus which will
prevent hyper-extension and lateral motion should be fitted to the
limb.
#Congenital absence of the patella# usually complicates other
abnormalities of the knee-joint. The tubercle of the tibia is
prominent and the extensor tendon unusually thick. In flexion the
tendon rises on to the lateral condyle of the femur.
#Congenital Dislocation of the Patella Laterally.#--This may be
persistent or intermittent. In the _persistent form_ the dislocation
is present from birth; the patella rests on the trochlear surface of
the lateral condyle, and when the knee is flexed may pass farther
outwards and become completely dislocated, lying against the lateral
aspect of the condyle.
In _the intermittent_ or _recurrent_ form the patella lies in its
normal place, but is liable to be displaced outwards when the joint is
flexed; the displacement occurs suddenly and unexpectedly in walking,
and the patient may fall to the ground, suffering intense pain. The
knee-cap is readily replaced on extending the joint, but the sprain of
the joint is followed by effusion, and the patient is usually disabled
for a day or two. It is met with chiefly in girls, and there may be a
history that the child was late in walking and learned with
difficulty. On examination, the patella is found to have an abnormal
range of movement outwards, although it cannot be completely
dislocated without considerable pain. If the child is brought for
advice when there is fluid in the joint, the condition is liable to be
mistaken for tuberculous synovitis. The observation that the undue
mobility of the knee-cap is present in both knees is of assistance in
arriving at a diagnosis, and also the history that the girl has
repeatedly hurt her knee in falling.
The cause of the abnormal mobility of the patella varies in different
cases; in some there is congenital laxity of the ligaments, in others
a faulty formation of the lower end of the femur. Bade has observed
families in which several children were affected, and although there
was nothing abnormal in the shape of the bones, the knee was slender
and delicately formed.
The use of a strong knee-cap may prevent falling, but as a rule an
operation is required, and there is quite a number to choose from, the
principle of them all being to prevent displacement of the bone
without unduly restricting flexion of the joint. That devised by
Goldthwait consists in exposing, by means of a vertical incision, the
whole length of the patellar ligament, splitting it longitudinally,
separating the lateral half from the tibia, passing it under the
medial portion and suturing it to the periosteum; this gives the
quadriceps a straight line of pull. We have achieved the same result
by dividing the lax capsule and synovial membrane on the medial side
of the patella, and overlapping the edges with a double line of catgut
sutures.
Lateral dislocation of the patella is met with in extreme forms of
_knock-knee_, and after correction of this deformity by osteotomy, and
its possible occurrence should be guarded against at the time of the
operation.
#Genu Recurvatum.#--In this deformity the knee is hyper-extended, the
thigh and leg forming an angle which is open forwards; the attitude
may be permanent or may only appear on walking. It is an extremely
disabling and unsightly deformity.
There are several varieties. In the _congenital form_, which is
apparently due to a faulty attitude of the lower extremities _in
utero_, the patella may be imperfectly developed or absent; the knee
is convex backwards, and attempts to flex the joint cause pain. Other
deformities frequently coexist. The treatment consists in flexing the
joint to a right angle under an anaesthetic, and maintaining this
attitude by means of plaster-of-Paris or splints until the growth of
parts overcomes any tendency to relapse.
_Acquired Forms._--The most common acquired form is the result of
anterior poliomyelitis, and is described in the next section.
The deformity may also be due to rickets which has caused a backward
bend of the tibia immediately below its upper epiphysis--sometimes
combined with an exaggerated forward curve of the femur. If there is
no prospect of spontaneous rectification, the upper end of the tibia
should be divided with the osteotome, and the limb straightened.
It may result also from fracture or from separation of one of the
epiphyses in the region of the knee, or from cicatricial contraction
of the quadriceps. As a result of bone and joint disease, it is met
with chiefly in neuro-arthropathies when the knee has become
disorganised and flail-like.
#Deformities of the Knee resulting from Anterior Poliomyelitis and
from Spastic Paralysis.#--When there is paralysis of all the muscles
acting on the knee, the joint may be so flail-like that the patient is
unable to stand without the aid of a crutch, or when weight is put on
the limb, it assumes the attitude of genu recurvatum. The usefulness
of the limb may be improved by the application of a rigid apparatus
with a lock at the joint so that it can be used in the extended
position for walking or in the flexed position for sitting. The rigid
knee produced by arthrodesis affords good support but is inconvenient
in sitting.
When the _quadriceps alone_ is paralysed, the patient is obliged to
maintain the joint in the position of extreme extension, because the
least degree of flexion results in the limb giving way under him. In
course of time the posterior ligament is stretched, and the joint
becomes hyper-extended, acquiring the attitude of _genu recurvatum_.
When it is bilateral the gait is seriously impaired. The treatment
consists in applying an apparatus which prevents hyper-extension, in
improving the condition of the thigh muscles, and in wearing a splint
at night which secures the flexed position. Recourse may be had to
operative measures, such as transplanting one of the hamstrings into
the patella, so as to compensate for the loss of power in the
quadriceps, arthrodesis, or supra-condylar osteotomy of the femur.
When the quadriceps is overcome by a _contraction of the hamstrings_,
as in spastic paraplegia, the knee is fixed in the flexed position and
the child is unable to walk. The flexion may be corrected by
lengthening the hamstring tendons, bringing the divided biceps tendon
through an opening in the vastus lateralis, and attaching it to the
rectus and to the patella. If there is a combination of flexion and
genu valgum, the knee-joint should be resected and ankylosed in the
straight position.
#Contracture and Ankylosis at the Knee.#--In addition to the different
paralytic forms above described, contracture may result from
ulceration and suppuration in the popliteal space, and from disease
(osteomyelitis) in one of the adjacent bones. The greater number of
contractures and ankyloses are the result of disease in the joint, and
have already been described.
GENU VALGUM AND GENU VARUM
In the normal limb, a line drawn from the centre of the head of the
femur to a point midway between the malleoli passes through the
centre of the knee-joint. If the line passes outside the centre of the
knee-joint, the condition is one of genu valgum; if inside, it is one
of genu varum (Fig. 135).
[Illustration: FIG. 135.]
#Genu Valgum--Knock-knee.#--In this deformity the leg joins the thigh
at an angle which is open outwards, and when the affection is
bilateral, the projecting knees tend to knock against each other in
walking; the term X-legs is sometimes applied to it.
_Etiology._--The observations of Macewen and of Mikulicz, and
information afforded by the Roentgen rays, have shown that the primary
cause of the deformity is an inequality of growth at the ossifying
junction of the femur or tibia or of both. This inequality of growth
is nearly always due to rickets, and its direction is determined by a
faulty attitude of the limbs in standing and walking. The legs being
abducted, the weight of the body falls unequally on the medial and
lateral parts of the ossifying junctions, and inequality of growth
results.
_Pathological Anatomy._--Examination of the femur usually shows that
the lower third of the diaphysis is lengthened on its medial side and
shortened on its lateral side, and that the epiphysis, itself
unaltered, is fitted on to the diaphysis obliquely, so that the medial
condyle appears to be increased in length and to occupy a level
distinctly below that of the lateral condyle. In many cases the tibia
shows corresponding alterations. On section of the bones, the
epiphysial cartilage and the zone of ossification are found to be
unduly broad and irregular.
[Illustration: FIG. 136.--Female child with right-sided Genu Valgum,
the result of Rickets. The pelvis is tilted, and the spine is curved.]
The neck of the femur is shortened and its angle diminished. The bones
of the leg are sometimes bent inwards in their lower thirds, and this
compensates partly for the valgus deformity at the knee. The articular
cartilage of the lateral condyle and the lateral meniscus are usually
thickened. In pronounced cases the quadriceps tendon and the patella
are displaced laterally, and this may be so pronounced that on flexion
of the joint the patella is dislocated on to the lateral condyle of
the femur. The biceps tendon and ilio-tibial band are shortened and
more prominent as a result of the approximation of their attachments,
and they are also displaced laterally. The sartorius and gracilis are
displaced backwards, so that they descend behind instead of on the
medial side of the knee. The popliteal artery lies on the back of the
lateral condyle instead of in the hollow between the condyles, and the
tibial (internal popliteal) nerve is displaced even farther outwards.
The capsular and other ligaments are slack, so that the joint is
unstable and easily hyper-extended. There is often some effusion into
the joint.
[Illustration: FIG. 137.--Female child with Rickety deformities of
upper and lower extremities.
(Mr. D. M. Greig's case.)]
_Radiograms_ reveal the changes in the bones (Fig. 138); the shaft of
the femur or tibia, or both, which may also be curved, is set
obliquely on its epiphysis; and the clear zone, corresponding to the
epiphysial cartilage, is uneven and broader than normal. There are
also less obvious changes in the density of the shadow and in the
arrangement of the trabecular structure of the bones.
[Illustration: FIG. 138.--Radiogram of case of Double Genu Valgum in a
child aet. 4.]
_Clinical Features._--In the infantile form (Fig. 139) the knock-knee
is commonly associated with rickets in other parts of the skeleton,
and especially with bending of the tibia and femur, and in extreme
cases the child may be unable to walk.
[Illustration: FIG. 139.--Genu Valgum in a child aet. 4. Patient
standing.]
The deformity is about as frequently bilateral as unilateral. There
may be knock-knee on the one side and bow-knee on the other. If, as is
usually the case, the deformity is due to obliquity of the femur, it
disappears on flexing the joint (Fig. 140), because in flexion the
tibia glides behind the projecting median condyle; if the deformity
affects the tibia only, the influence of flexion in disguising it is
not so marked. It is usually possible to hyper-extend the joint, and,
in the extended position, to rotate the leg outwards to a greater
extent than is normal. In unilateral knock-knee, the affected limb is
a little shorter than its fellow, but the patient compensates for this
by depressing the pelvis on the affected side.
[Illustration: FIG. 140.--Genu Valgum. Same patient as Fig. 139.
Sitting, to show disappearance of deformity on flexion of knee.]
_Prognosis._--In children below the age of six, the bones naturally
tend to straighten if the child is kept off its feet. After this age,
there is no such prospect.
The _treatment of knock-knee in children_ is directed towards curing
the rickets and preventing the child from putting its feet to the
ground. If it cannot have the services of a nurse and the use of a
perambulator, a light padded splint is applied on the lateral side of
the limb, extending from the iliac crest to 3 inches beyond the foot.
The splint is fixed above and below by bandages, and the projecting
knee is drawn towards it by a few turns of elastic webbing. A method
specially applicable to hospital out-patients, is to straighten the
limbs as far as possible under anaesthesia, and apply a plaster
bandage; the bandage is renewed at intervals of three weeks until the
deformity is corrected. Whatever plan is adopted, it must be
persevered with for at least six months, until the rickety changes in
the bones have been entirely recovered from.
If the child is approaching the age of five or six before it comes
under treatment, or if the deformity does not yield to treatment by
splints, it is better to straighten the limb by _osteotomy_.
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 coarse 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 pass 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 attitude 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 associated 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 sturdy on their legs. An extreme example of the
deformity is shown in Fig. 141.
[Illustration: 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 associated with knock-knee or bow-knee. They
may occur before the child is able to walk, the bones bending in the
attitude 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 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
Roentgen 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 foetal 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.
[Illustration: 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.
[Illustration: 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 pronounced 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
adventitious 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).
[Illustration: 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 massaged and douched. At the end of two or three
months, assistance 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
attitude and the plaster is applied so as to maintain this attitude.
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 massage 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 attitude. The majority of surgeons defer
operative measures until the child is about a year old.