++
Medial deviation of the forefoot of an infant, termed metatarsus
adductus, is one of the most common pediatric foot conditions
(Fig. 213-1). Intrauterine positioning—medial
rotation of the foot across the fetal torso—is the presumed
cause of this positional deformity. The “deformity” is
usually flexible and can be passively corrected, in which case no
treatment is actually necessary. Rare cases with severe rigid deformity
may require treatment.1
++
++
Clinically, the forefoot is medially deviated in relation to
the hindfoot. When viewed from the plantar surface, the lateral
border of the foot is curved and appears “bean shaped” (Fig. 213-1B). There may be additional medial
deviation of the great toe and the appearance of a high arch.2 The
deformity can be passively “corrected” if the
examiner grasps the heel and maintains it in the neutral position,
while abducting the forefoot (eFig. 213.1).
Metatarsus adductus is almost always bilateral, although some children
will demonstrate a “windswept” position of the
feet, with one foot internally rotated with metatarsus adductus,
and the opposite externally rotated by the intrauterine position.
++
++
Many children will present at walking age with intoeing. Metatarsus
adductus is but one reason the foot progression angle can be deviated
medially—the most common being internal tibial torsion
(ITT). By observing the plantar surface of the foot (Fig.
213-1), the contribution to the intoeing coming from the forefoot can
easily be appreciated and differentiated from ITT. Metatarsus adductus
is distinguished from talipes equinovarus (clubfoot) by noting that
the ankle and hindfoot have a normal range of dorsiflexion and plantarflexion,
whereas a true clubfoot has a fixed hindfoot deformity (see discussion
below). Rarely, the forefoot may be medially deviated in a foot
that appears to have severe midfoot and hindfoot valgus, a foot
that is commonly described as skewfoot (see discussion below).
++
Treatment of metatarsus adductus varies from observation to casting
in more severe presentations.2,3 If the forefoot
can be passively manipulated into a corrected position, then the parents
can be instructed in passive stretching, and the “deformity” can
be observed. Full resolution can be expected. Night splints or reverse-last
shoes for children younger than 6 months can also be utilized, although
there is little evidence that such orthotic treatment facilitates what
would otherwise be spontaneous resolution. If the forefoot is not
passively correctable, a short period of casting may be warranted. If using
short leg casts, one must carefully insure that the heel is not
pushed into valgus during the maneuver to abduct the forefoot and straighten
the lateral border (eFig. 213.1).
++
Surgical correction is reserved for the rare patient with a fixed
adductus, and symptoms. The decision for operative treatment, whether soft
tissue release or bony procedures, is controversial. Orthopedic
consensus is that, even with moderate fixed residual adductus, adult function
is still normal.2,3
++
This postural deformity of infancy is characterized by a sometimes
dramatic hyperdorsiflexion position, where the dorsum of the foot is
plastered to the anterior surface of the tibia (Fig.
213-2). Plantarflexion is limited,
and the condition may seem severe if the contractures of the dorsal
ankle structures do not allow early manipulative relief (eFig. 213.2).
++
++
++
The foot may also be deviated laterally, the “valgus” portion
of the deformity, preventing inversion of the foot. The key is to
determine whether the heel is also in dorsiflexion. If the heel
has descended and moves appropriately upward when the forefoot is
plantarflexed, one may conclude that this is a postural, in utero
deformity, resulting as a “packaging” defect,
which will resolve with time and manipulative stretching.4,5 On
the other hand, if the heel has not descended with the hyperdorsiflexed
forefoot or does not move appropriately when the forefoot is raised
and lowered, then a congenital vertical talus must be ruled out.
The latter is usually characterized by the foot having a “rocker
bottom” appearance, due to the fixed equinus of the heel
(see discussion below). Hip dysplasia must be ruled out in the newborn
with a hyperdorsiflexed foot, because the same abnormal in utero
fetal position responsible for the calcaneovalgus foot can also
cause hip dysplasia.5 A less subtle deformity is
a posteromedial bow of the tibia that may present concomitantly
with the calcaneovalgus foot. In the latter, the tibia is deformed
with an apex based posteriorly, which is easily understood as an
additional packaging defect associated with the hyperdorsiflexed
foot.6 However, the posteromedial bow of the tibia
will require some orthopedic intervention due to the shortening
of this portion of the lower extremity.
++
Once congenital vertical talus, posteromedial bow of the tibia,
and hip dysplasia have been ruled out, then The hyperdorsiflexed
foot can be treated by gentle manipulation and stretching, pushing
the foot into plantarflexion (eFig. 213.2).
Such stretching exercises can be taught to the parents. Inversion
of the foot may also be carried out as a corrective maneuver. Typical
calcaneovalgus foot will resolve spontaneously in a period of 3
to 6 months, although occasionally a more severe case may be referred
to the orthopedist for either splinting or casting. Parents should
be educated as to the benign nature of this deformity, but they should
also be warned that there may be a flatfoot appearance when ambulation
begins.
+++
Flexible Flatfoot
(Pes Planovalgus)
++
Flatfoot is probably the most common “deformity” evaluated
by pediatric orthopedists. Whether it constitutes an actual deformity
is, in fact, questionable.7 In general, the weight
of the child’s body in the presence of lax ligaments in
the foot flattens the normal arch. In the infant and pretoddler
child, a “fat” foot should not be mistaken for
a flatfoot, as the arches of infants and young children are often obscured
by subcutaneous fat.8 Finally, a lower arch is
a normal variant. It is thus surprising that flatfoot is evaluated
and treated, often prophylactically by nonorthopedic branches of
medicine, fearing that the loss of the longitudinal arch, however
subjective, will result in symptomatic disability.
++
There is no universally accepted definition of flatfoot. The
normal height of the longitudinal arch is unknown, and radiographic
analysis of the foot is rarely indicated if the physical examination
does not reveal a specific indication (see discussion below). The
appearance of a flatfoot is well known—the heel is everted with
a loss of height, and the talar head and navicular appear to rest
on the floor medially. The medial column of the foot may appear
longer than the lateral column. When viewed from behind, the examiner
may note that all five toes are visible to the lateral side of the
tibia (called “too many toes” sign) (eFig.
213.3). However, while observing the child from behind, the
examiner may request that the child go up on tiptoes, at which time
in the flexible flatfoot, the longitudinal arch will reconstitute,
and the heels will invert (eFig. 213.3C).
This simple maneuver basically rules out any significant congenital
foot pathology. When examining the foot with the child seated and
the foot dangling, the flexible flatfoot will demonstrate ease of
inversion and eversion, and again the longitudinal arch will be
seen to reconstitute.
++
++
The differential diagnosis of flatfoot includes conditions such
as congenital vertical talus, in which the heel is in equinus and
will not correct, and tarsal coalition, in which there is marked
restriction of subtalar and midfoot movement, most easily detected
by the tiptoes test just described. Tarsal coalition usually presents
in older children, typically because of pain.
++
A decreased longitudinal arch has been described in as much as
a quarter of the adult population, and thus must be considered a
normal variant. This, however, does not remove the possibility that
the patient may have symptoms, which are almost always associated
with a contracture of the triceps surae9 and can
be detected by dorsiflexion of the foot with the heel stabilized
in neutral and the knee fully extended. Patients with a tight triceps
complex tend to have more complaints from their flexible flatfeet. Should
heelcord contracture be suspected, the child should be asked to
walk on his or her heels, which will be difficult with a significant
contracture.
++
Treatment of flexible pes planovalgus depends on the presence
or absence of symptoms. Asymptomatic flatfeet require no treatment, with
education and reassurance being given to the parents. There is no
evidence that prophylactic treatment of flexible pes planovalgus
prevents either the development of symptoms or the progression of
a deformity.10,11
++
In symptomatic patients, a variety of shoe inserts, shoe modifications,
and exercises are available. If the child has a tight heel cord,
then exercises to stretch the gastrocsoleus complex are indicated
(eFig. 213.4). The most effective exercise
is the gentle dorsiflexion of the foot with the heel stabilized
in neutral and the knee in full extension. Calf muscle stretching
by leaning forward with the feet inverted, knees extended, and hands
on a wall is also recommended (eFig. 213.4). For
heel eversion, a medial heel wedge attached to the sole of a shoe may
be useful, and with more symptomatic feet, the use of a soft or
rigid insert to invert the heel and support the longitudinal arch
are often considered (eFig. 213.5). There
is no evidence, however, that any of these corrective devices change
the anatomic structure of the foot. In light of the not-insubstantial
costs of some of the custom-molded orthotics, there is little justification
for prescribing such devices unless symptoms warrant. Perhaps the
most effective shoe modification for the child with painful flexible pes
planovalgus is the recommendation to purchase “running
shoes” from an athletic store. Such running shoes, often
prescribed for “hyperpronated feet,” include most
of the modifications, such as a medial heel wedge, arch support,
and rigid heel cup, which are normally prescribed by physicians
and gladly provided by orthotists. The use of such running shoes makes
prescription of these additional orthoses unnecessary.
++
++
++
There are occasionally older adolescents whose hypermobile flatfoot
continues with intractable symptoms in spite of stretching exercises
and shoe and orthotic prescriptions. Such patients are rare and
represent the only true candidates for surgical management. Because many
of the surgical procedures for hypermobile flatfoot are often unsatisfactory
in long-term outcomes, pediatric orthopedists are reluctant to recommend
such treatment except in the most dire of circumstances. In order
to change the anatomic position of a hypermobile flatfoot, some
form of stiffening of the joints of the foot—either by
imbrication, osteotomy, or fusion—must be applied to the foot. Although
short-term efficacy is to be expected, longer-term studies report
unsatisfactory results from such surgery,12-14 because all
of these stiffening maneuvers will result eventually in osteoarthritic
changes within the foot at the adjacent unfused joints. For this reason,
only the most recalcitrant of hypermobile flatfoot is ever considered
for surgical correction.
++
This rare deformity resembles metatarsus adductus but also has
the elements of hindfoot valgus and is usually more rigid and severe than
any metatarsus adductus alone (eFig. 213.6). Skewfoot
has also been termed serpentine or Z-foot,
based on the radiographic deformity (eFig. 213.6). Patients
will usually present because of discomfort under the base of the
fifth metatarsal or under the head of the talus on the medial side.
The rigidity of the skewfoot is the striking difference between
its relatives, simple metatarsus adductus or simple hypermobile
flatfoot.
++
++
Patients usually present in older childhood or adolescence when
pain and complaints become more severe.15 Because
of the later presentation and rigidity, nonoperative methods are
rarely successful. Operative treatment may be indicated if symptoms
warrant and is often complex due to the rigid deformities at multiple
points from the heel to the forefoot.
+++
Clubfoot (Talipes Equinovarus)
++
Clubfoot is probably the best-known pediatric foot condition
requiring treatment, having been known since ancient times. It represents congenital
dysplasia of all musculoskeletal tissues distal to the knee and
is present in 1 to 2 per 1000 live births. Ancient practitioners struggled
with producing an acceptable outcome for clubfoot just as modern
orthopedists do because of the myriad of pathologic findings that
prevent an optimal outcome from being achieved. Regardless of whether
a clubfoot is corrected nonoperatively or operatively, there always
appears to be some degree of impairment in the function of the extremity, due
to restricted motion in the ankle and hindfoot, diminished muscle
strength and power generation of the triceps surae, and kinetic
and kinematic abnormalities related to atrophy and fibrosisof the
musculoskeletal tissues below the knee. Clubfoot is a congenital
abnormality that begins developing prior to the 12th week of gestation;
thus, by the time the infant is born, the congenital dysplasia of
the lower limb has been present for up to 7 months of intrauterine
life.16,17
++
Evidence of such dysplasia is noted when one looks, for example,
at the severely dysmorphic bones of the fetal clubfoot (eFig. 213.7). This difference, combined with
the soft tissue fibrosis that impairs manipulative correction, defines
why clubfoot is a serious congenital anomaly. Modern treatment, which
has returned to an emphasis on nonoperative methods, seeks early
anatomic correction while at the same time providing as much motion
as possible to counteract atrophy and muscle weakness. Clinical
identification of the clubfoot is rarely difficult. The classic
appearance of the heel in marked equinus with the foot severely
inverted on the end of the tibia is unmistakable (Fig.
213-3). The foot may approach a position of being upside down in
relation to the normal position. Lack of correctability of the inversion
and the heel equinus separates the true clubfoot from a more mild postural
deformity. At the time a newborn infant with a clubfoot is evaluated, Other
associated syndromes or conditions, such as Down syndrome, arthrogryposis (eFig. 213.8), skeletal dysplasias, spina
bifida or spinal dysraphism, or other trisomy and dysmorphic conditions
should be kept in mind. Although concomitant dysplasia is reported
to occur in less than 1% of patients with idiopathic clubfeet,
a screening hip examination should always be done.
++
++
++
++
The infant with a clubfoot should be referred quickly, as it
is generally agreed that the earlier treatment is begun, the more
likely that nonoperative methods will be successful. This is due
to the relatively viscoelastic character of the newborn foot, which
rapidly becomes nonelastic if treatment is delayed beyond the age
of 3 months. Nonoperative treatment has become the mainstay because
of the clearly unsatisfactory long-term results obtained with surgery,
based on many studies demonstrating that surgically treated feet
are stiffer and weaker, due to scarring and muscle atrophy.18,19 Nonoperative
treatment proposes to gradually correct the clubfoot deformity without
producing the scar tissue that inevitably diminishes the result.
++
Two methods of nonoperative treatment are currently employed.
The first is serial casting, described and popularized by Ponseti
of the University of Iowa.20 This method, which
involves weekly manipulation and cast application, proposes to correct
the foot and allow relaxation of the collagen and remodeling of the
osseous structures without producing fibrosis and scarring. The
technique is usually spread out over 4 or 5 cast applications done weekly
(Fig. 213-4), with a percutaneous heel-cord
release done prior to the final cast to bring the foot out of equinus,
commonly the most recalcitrant of the four major deformities (cavus,
adductus, varus, equinus) that characterize a clubfoot. The retention
of the corrected position by a long-leg cast is an important aspect
of the Ponseti method, as is the percutaneous heel-cord prior to
the final casting Over the 5 weeks of casting, the foot is gradually
brought out of cavus and externally rotated, with the dorsiflexion
of the foot being the final maneuver assisted by the percutaneous TAL
(tendoachilles lengthening). A certain degree of “overcorrection” is
sought by the final cast so as to ensure full derotation and correction
of the initial cavus, adduction, and varus (Fig.
213-4). Following removal of the last cast, an equally important
period begins of bracing the foot in the corrected position by the
use of a Denis Browne bar attached to shoes which maintains the
feet in 50 to 70 degrees of external rotation (eFig.
213.9). The orthosis is worn full time for a period of 4 months,
and then part time for up to 2 years to maintain the correction.
++
++
++
The results of the Ponseti technique have generally been favorable,
with 90% of patients undergoing early treatment avoiding
surgery20 (the percutaneous TAL is not considered
a surgical procedure as it is part of the initial protocol). The
avoidance of early surgical procedures is one of the great advantages
of the Ponseti method, and long-term outcomes document that by physical
examination over half the feet are considered “normal,” although there
are both motion and radiographic changes that characterize the residual
of any clubfoot. It must be realized, however, that relapses of
corrected clubfeet with the Ponseti method are relatively common,
requiring additional casting, limited surgical releases, or tendon
transfers in order to obtain correction over the longer term. Most
studies, however, report a high degree of success with Ponseti’s method
despite recurrences reported for up to one third of the patients.
++
The second nonoperative method is termed the functional or French
method, having been developed in Europe, primarily by French orthopedists,
in the 1980s.21 The method is considered functional
because the foot is stretched daily by trained physiotherapists,
with the correction being maintained overnight by a method of taping.
The passive manipulations are combined with active stimulation of
dorsiflexors and peroneal muscles for a period of 2 to 6 months.
Nighttime splinting for up to 2 to 3 years follows.
++
The French method became known in the United States in the 1990s.
Its primary deficiency is the fact that trained physical therapists
are necessary for it to succeed, and it is considerably more time
consuming than the weekly castings of the Ponseti method. Cooperation
and transportation of families is essential for such a program to
work, and obviously, patients who live a long distance from the
treatment center cannot participate successfully. Nevertheless,
in patients able to undergo the French method, similar results have
been obtained in the short term, with surgical releases generally
being avoided in the first year of life.21 Posterior
release, however, is frequently required, because the equinus deformity
is not addressed surgically until the child begins ambulation.22 Residual
equinus, the most resistant of the clubfoot components, may not
be adequately corrected except by percutaneous TAL or posterior
release, frequently delayed until ambulatory age.
++
Surgical correction is appropriate for a foot that is resistant
to nonoperative methods. Although many orthopedists believe that
surgery is the only method to completely correct a severe clubfoot,
the long-term outcome of the surgically treated feet, critically
reviewed in the 1990s by several investigators,18,19 demonstrates
that multiple operations are common but need to be avoided, and
that recurrence is almost always due to incomplete correction. The
stiffness and atrophy as well as scarring from operative procedures
leave no doubt that surgery for clubfoot should not be the primary
choice.
++
Typically surgery is performed around walking age in the patient
who has failed nonoperative methods early due to intolerance of casting,
intolerance of posttreatment bracing (DB bar), or noncompliance
with either of the nonoperative protocols. There is
no advantage to performing surgery earlier than walking age, because
the ability to be fully weight-bearing in the postoperative period
may in fact be of great assistance in maintaining correction by encouraging
a plantigrade foot with no equinus. Soft tissue releases are recommended
as the first approach at this age and include extensive ligament
and tendon releases and lengthenings, from the posterolateral corner
of the ankle and subtalar joint to the medial side of the midfoot. The
extent of the procedure must be evaluated intraoperatively in order
to ensure that both under- and overcorrection are avoided. As mentioned
earlier, although undercorrection is most frequently the cause of “relapse” and
leads to repeated surgical procedures, overcorrection into excessive
valgus and dorsiflexion can also occur, with debilitating long-term
functional implications. The surgeon who is the first to operate
on a congenital clubfoot bears a great responsibility in that subsequent
operative procedures will almost certainly be regarded as salvage,
and whatever improvement in anatomic position that is achieved will
almost undoubtedly be accompanied by functional disability due to
weakness and stiffness.18,19
++
Congenital clubfoot remains a treatable but somewhat unsolved
problem in pediatric orthopedics. The outcome of treatment depends significantly
on the severity of the deformity at presentation, as well as the
timeliness and competence of the nonoperative treatment. Competence
and timeliness notwithstanding, success also depends significantly
on the compliance of the family in maintaining the corrected foot
in an appropriate orthosis until walking age, with timely limited
surgery being appropriate if there is residual deformity or recurrence
following the initial nonoperative method of infancy.
+++
Congenital Vertical Talus
++
Congenital vertical talus (CVT), also known as congenital convex
pes valgus, is a rare foot anomaly, typically differentiated from
clubfoot by the appearance of the foot resembling a rocker-bottom
deformity (Fig. 213-5). The pathology in
CVT is a teratologic dorsal dislocation of the talonavicular joint,
in which the midfoot and subtalar joints are dislocated dorsally
and laterally while the heel is still fixed in equinus (Fig. 213-5B). In a sense, the reverse of
the inverted cavus deformity represents clubfoot.
++
++
CVT often presents in association with arthrogryposis or myelomeningocele
and various trisomy syndromes. In fact, idiopathic vertical talus is
a relatively rare entity, so the patient presenting with a true
convex pes valgus must be evaluated for a generalized condition
or syndrome.
++
Clinically the foot has a rocker-bottom appearance, due to the
heel being in equinus, combined with the talar head presenting itself in
the medial plantar sole of the foot (Fig. 213-5).
The forefoot is everted and dorsiflexed and cannot be inverted,
due to the contracture of the soft tissues of the dorsum and lateral
aspect of the ankle. The navicular is palpable on the dorsum of
the talar neck.
++
A lesser degree of severity may manifest itself as an oblique
talus. In this situation, the dorsilateral structures of the ankle
are not as severely contracted, and the navicular can be reduced
onto the head of talus when the forefoot is plantarflexed and inverted.
The heel remains in some degree of equinus.23 This feature—the
residual equinus of the calcaneus—and the resulting plantarflexion
of the talus describe the radiographic appearance on the lateral
X-ray which gives the condition its name—the talus is vertical
and parallel to the longitudinal axis of the tibia (eFig.
213.10). Any foot of a newborn or young child which has heel
equinus, a rocker-bottom appearance, and lack of inversion and plantarflexion should
be suspected of having CVT.
++
++
Differential diagnosis for CVT includes a calcaneo-valgus foot.
The latter deformity is not easily confused when the heel is seen
to descend appropriately when the foot is dorsiflexed. At walking
age, a severe flatfoot with a heel-cord contracture may also be
mistaken for a vertical talus. This is differentiated by the fact
that flatfoot can be inverted and plantarflexed, with the navicular
reducing on the head of the talus, and whatever valgus is seen in
the flatfoot can also be corrected by inversion. No such flexibility
occurs with CVT. Obviously, if any doubt remains following clinical
evaluation, a lateral radiograph of the foot in plantarflexion will
settle the issue (eFig. 213.10).
++
Treatment of the congenital vertical talus includes early casting
in an attempt to stretch the contracted dorsilateral structures
and reduce the navicular on the talus, followed by operative open
reduction of the talonavicular joint and release of the hindfoot
equinus. The procedure is similar in many ways to the clubfoot release
and can be done at any age from immediately prewalker to mid-childhood,
depending on the time of recognition of the deformity. The results
tend to be better in children under the age of 2, and older children usually
require some form of joint stabilization by arthrodesis in order
to prevent recurrence.24 Long-term functional outcome
of CVT is uncertain, because most patients with CVT have various
disabilities and low functional demands due to comorbidities associated
with their underlying syndrome or chromosomal abnormality.
++
This condition usually presents as a painful flatfoot. By definition,
there is an abnormal lack of segmentation between two or more bones
of the foot, and this accounts for the rigidity and pain that bring
the patient for evaluation.25,26 Because of the
rigidity and appearance of the foot, the condition is also known
as peroneal spastic flatfoot.
++
Patients typically present between the ages of 12 and 16 years,
although some coalitions have been documented in children as young
as 6 years.27 Pain is almost always the initial complaint
and is often located in the tarsal sinus, though it may also be
present under the medial malleolus and along the arch of the foot.
Pain is often activity related, and patients may notice a progressive
external rotation and flatfoot, the latter being responsible for
the medial arch discomfort.
++
The predominant physical finding is decreased range of motion
at the subtalar joint, best demonstrated by lack of inversion. Patients
are often unable to stand on tiptoes without discomfort, and there
is a noticeable lack of inversion of the heel when the tiptoe position
is requested. This is in contradistinction to the physical findings
of a flexible flatfoot. The hindfoot may be in significant valgus
as well, and the resistance to passive inversion is often attributed
to spasticity of the peroneal tendons—hence, peroneal spastic
flatfoot.
++
The diagnosis should be suspected in any adolescent with painful
flatfeet and restricted inversion. Plain radiographs should include
anteroposterior (AP), lateral, and oblique views. A calcaneonavicular
coalition, the most common tarsal coalition, is usually readily
apparent on the oblique x-ray (eFig. 213.11).
On the lateral x-ray, secondary changes suggestive of medial facet
talocalcaneal coalition (eFig. 213.11B) include
talar beaking and the “C” sign, a crescentic bony
ridge underneath the talocalcaneal joint. True visualization of
a medial facet coalition usually requires a computerized tomography
(CT) scan (eFig. 213.11) with the appropriate
coronal plane cuts across the subtalar joint (eFig.
213.11C). Coalitions involving other foot joints, including
talonavicular, calcaneocuboid, and others, are rare but can usually
be recognized on plain radiographs of the feet.
++
++
The differential diagnosis of painful rigid flatfeet includes
inflammatory processes involving the subtalar joint, as with pauciarticular
juvenile arthritis. A difficult clinical problem is the patient
with classic symptoms and findings of a tarsal coalition but in
whom no coalition can be identified radiographically. Occasionally
fibrous coalitions are found, but surgical treatment of such cases
frequently is ineffective or the patient develops recurrence.
++
Treatment of tarsal coalition, documented radiographically or
suspected, should be conservative initially, including the use of
orthoses, a short period of casting, and injection of the involved
subtalar joint with a combination of local anesthetic and steroid.
The latter serves both as a diagnostic as well as a therapeutic
modality, with some patients receiving long-term relief of the pain
for reasons that are not known. but presumably have to do with decreasing
the inflammatory response produced either by the abnormal subtalar
motion or an intra-articular pain generator. Patients who fail conservative
treatment with documented coalitions are then candidates for either
resection of the coalition or subtalar midfoot arthrodesis. A calcaneonavicular
coalition is easily excised, and the defect created by the excision
is filled with subcutaneous fat taken locally from the same lower
leg. A medial facet talocalcaneal coalition is more difficult to
resect, with subsequent motion more difficult to achieve. If the
coalition is not completely removed, the abnormal subtalar motion
will continue. Most authors report success resecting calcaneonavicular
coalitions, but talocalcaneal coalitions are more unpredictable.28,29 Large
coalitions, as well as average size coalitions in obese patients,
seem to be most likely to fail. In the latter circumstance, the
presence of a large medial facet coalition may best be treated by
subtalar fusion rather than an attempt at resection. The best treatment
for medial facet coalitions remains controversial.
++
The cavus foot is defined by an abnormal elevation of the longitudinal
arch. The deformity has complex underlying etiologies and consists
of both forefoot equinus and varus as well as pronation of the midfoot.
The etiology of pes cavus is often neurologic,30,31 with
the most common underlying diagnoses being peripheral neuropathies
such as Charcot Marie Tooth disease and tethered spinal cord. Other
diagnoses include cerebral palsy, poliomyelitis, Friedrich’s
ataxia, and myelomeningocele. Idiopathic pes cavus exists but must
be made as a diagnosis of exclusion.
++
The clinical features of a cavus foot include plantarflexion
of the forefoot with a high arch, with some degree of varus of the
hindfoot and pronation of the first metatarsal (eFig.
213.12). The latter deformity produces an inversion and varus
of the entire foot by the tripod effect32 (eFig. 213.12), as the plantar surface of
the first metatarsal is the first portion of the foot to strike
the ground during weight bearing, then producing an inversion of
the entire foot and varus of the heel. Patients typically present
because of pain under the lateral aspect of the foot due to excessive
weight bearing, as well as complaints of frequent lateral ankle sprains
due to the forced inversion in association with whatever muscle
imbalance or weakness is present from the neuropathic etiology.
++
++
The clinical deformity may be fairly mild, if the primary deformity
is only a high arch. Inversion of both the forefoot and hindfoot
usually produce callosities or pain under the lateral border of
the foot due to the abnormal weight bearing in a more advanced case
(eFig. 213.13). Secondary changes, again
due to the progression of neuropathic changes, include cock-up and
clawing deformities of the toes (eFig. 213.14).
Determining the underlying etiology of a cavus foot is the first
priority because of possible treatment of conditions involving the
spinal cord (including tumors) or the underlying neurologic condition.
Conservative measures to relieve the abnormal weight bearing and
ankle instability include orthoses to balance the weight-bearing
surface of the foot or ankle–foot orthoses (AFOs) to stabilize the
ankle, and in the case of a muscle weakness etiology, assist with
dorsiflexion. Such methods may be quite efficacious but frequently
due to progression of the neuropathic condition, the foot deformity
progresses to require surgical stabilization.
++
++
Surgical procedures to correct a cavus deformity are as numerous
as there are underlying etiologies producing it. Depending on the etiology
and the severity of the neural imbalance, such procedures as plantar
fasciotomy, osteotomy of the first metatarsal and calcaneus, or
midfoot osteotomy may be required alone or in combination to create
a plantigrade foot with a decreased longitudinal arch and removal
of hindfoot varus, thus stabilizing the ankle.32,33 In
recurrent or more progressive cases, some form of hindfoot and midfoot
arthrodesis, with or without first metatarsal osteotomy to dorsiflex
the forefoot equinus, is often required. The surgical goal is to
provide stable plantigrade feet that do not require bracing unless
the patient also has a foot drop due to weakness of the tibialis
anterior muscle.
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Hallux Valgus (Bunion)
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Hallux valgus in a pediatric orthopedic practice is usually seen
in adolescent females who are concerned about cosmesis as well as
pain. A positive family history is present in up to three quarters
of the patients, and the concern becomes more significant as the
child enters adolescence. The deformity consists of lateral deviation
of the great toe, with the apex at the first metatarsophalangeal
joint (Fig. 213-6). The prominence of the
head of the first metatarsal is usually responsible for the discomfort,
but the lateral deviation with under- or overlapping of the second
toe produces the cosmetic concern. Patients with hallux valgus usually
have a rather wide forefoot, making narrow “fashionable” shoes
difficult if not impossible to don (eFig. 213.15).
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Occasionally,
there is an underlying condition associated with the hallux valgus,
which may be mild cerebral palsy or connective tissue conditions
such as Marfan syndrome or Ehlers-Danlos syndrome. There is controversy
whether a flexible flatfoot can actually lead to hallux valgus,
as well as the likelihood of recurrence of a hallux valgus deformity
in the patient with an uncorrected or untreated flatfoot.34,35
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Pediatric patients with hallux valgus should initially be strongly
encouraged to avoid surgical treatment. Surgical procedures to straighten the
deformity are fraught with untoward effects and complications, not
the least of which is recurrence if the patient is skeletally immature
or has a significant flexible flatfoot.34,35 Because most
procedures involve imbrication of the first metatarsal-phalangeal
joint to help maintain correction of the deformity, a certain degree
of stiffness will be imparted to this joint, which may impact athletic
activities such as running, as well as be the precursor for degenerative
arthritis. Unfortunately, the latter can occur in the untreated
hallux valgus, and thus there is no consensus on the value of prophylactic
correction in adolescents.
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If the patient is skeletally immature, surgery should be delayed
until maturity, as the risk of recurrence is exceptionally high
in younger patients.35 Treatments such as night
bracing and stretching exercises of the great toe have value, although
there is no evidence that this will provide a long-term solution. Toe
spacers and other splints can be tried and may have short-term benefit
but again eventually will be unsatisfactory. In patients with pes
planovalgus, an arch support and other shoe inserts to decrease
the valgus pressure on the great toe are appropriate.
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Surgical treatment for the mature adolescent is similar to the
treatment for the adult, in that a combination of osteotomies, soft
tissue releases, and capsular imbrication are usually used (eFig. 213.15). The indications for the various
osteotomies, as well as other adjunctive procedures to displace
the great toe dorsally or medially, are sources of orthopedic controversy
yet to be resolved. In failed hallux valgus surgery, the final common
procedure is a metatarsal-phalangeal fusion, often considered an
unsatisfactory outcome because it sacrifices the important function of
the great toe during running and push-off.
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Extra toes are probably the most common congenital toe deformities
noted, with an incidence of almost 2 per 1000 live births. A positive
family history is present in one third of the patients, with the
fifth toe being the most frequently duplicated (postaxial polydactyly) (eFig. 213.16).36 Duplication
of the fifth toe probably accounts for 80% of the cases
of polydactyly of the foot. Preaxial (duplication of the great toe)
is less common (eFig. 213.16C) and is seen
in association with syndromes including trisomy-13, tibial hemimelia,
and Down syndrome.
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Removal of a duplicated fifth toe can be accomplished at essentially
any time but is probably best done around walking age. This allows
the toes to enlarge to a point where the surgery is technically
simple due to ample skin and soft tissue for coverage. An important aspect
of this waiting is also to make the risk of anesthesia less severe
than it would be if the surgery were done in a newborn. For duplication
of the great toe, general guidelines for when surgery should be
attempted are more difficult, because the variety of duplications vary
from simple to complex, and some consideration for no treatment
should be made if the deformity is not significantly bulky and,
as in most cases, the function is nondisturbed. In cases, however,
where there is deformity associated with the duplication (eFig. 213.16C), surgical treatment is appropriate
when the child begins ambulating and shoe wear becomes an issue.