Foot Disorders

Metatarsus adductus is believed to be caused by
intrauterine compression or “packaging”. This etiology has not been
proven. Presumably, the feet are compressed during intrauterine
development.

About 1% of infants will demonstrate metatarsus
adductus. The condition may persist longer in premature babies.
First-born babies, large babies, and twinning may predispose to
metatarsus adductus due to intrauterine crowding. Metatarsus adductus
is reportedly seen in association with developmental dysplasia of the
hip, although several large series have not borne this out.
Theoretically, the packaging problem that leads to metatarsus adductus
can also affect the adducted hip. Therefore, the child presenting with
metatarsus adductus should have a careful hip examination. Pelvic
imaging is necessary only if there is a positive finding on the hip
examination.

Medial subluxation of the tarsometatarsal joints,
adduction of the metaphysis of the second through the fifth
metatarsals, and medial deviation of the articular surface of the
medial cuneiform have been demonstrated in stillborn infants with
metatarsus adductus.

Metatarsus adductus can be classified based on the
flexibility of the deformity. The three classification grades are:
actively correctable, passively correctable, or rigid. Actively
correctable feet straighten out when the lateral border of the foot is
stroked by the examiner’s finger and the muscles of the child’s foot
contract correcting the C-shape to neutral. The passively correctable
foot straightens out with gentle manipulation. To manipulate the foot,
grasp the heel with one hand and push the inward-turning forefoot
outward with your other hand in order to realign the foot in a straight
position and reverse the C-shaped outer border of the foot. The rigid
metatarsus adductus does not correct with manipulation. The rigid case
typically has a medial soft tissue crease at the tarsometatarsal level
with a medial soft tissue contracture. As the forefoot is pushed
laterally, the great toe will abduct and a tight abductor hallucis can
be palpated medially.

The amount of adduction can be quantified grossly by extrapolation of a line bisecting the heel up to the toes (Fig. 4.1-1).
This heel bisector should hit between the second and third rays of the
foot. If it hits the third ray, the metatarsus adductus is mild; the
fourth ray, moderate; and the fifth ray, severe. This measurement can
be used to follow the deformity over time.

The diagnosis of metatarsus adductus is made clinically (Box 4.1-1).
Radiographs are rarely needed. The outer border of the foot is curved
or C-shaped. When viewed from the dorsal surface, the entire foot
appears to be turned inward. When the foot is viewed from the plantar
surface, the sole of the foot has the shape of a bean. The base of the
fifth metatarsal may appear prominent. The arch may appear high. The
space between the first and second toe may appear wide. The first toe
often seems to be reaching medially. The ankle joint and heel alignment
are normal or in slight valgus in metatarsus adductus. If the foot
demonstrates a fixed valgus hindfoot then the child does not have
metatarsus adduction: instead the diagnosis of skewfoot (forefoot
adductor, midfoot abduction, and heel valgus) should be considered. The
ankle joint is supple in metatarsus adductus. For example, the foot
could easily dorsiflex above the neutral position. If the foot
demonstrates fixed equinus and cannot dorsiflex, and the hindfoot is in
a varus position, then the child does not have metatarsus adductus:
instead the diagnosis of clubfoot should be considered.

Radiographs of the feet are rarely needed for the
diagnosis or treatment of metatarsus adductus. Radiographs are taken in
the rare case undergoing surgery or in the patient being evaluated for
possible skewfoot. Radiographs should be taken in the weightbearing
position. Metatarsus adductus radiographs show medial deviation of the
metatarsals at the tarsometatarsal joints and in some cases medial
deviation of the metatarsal shafts. Radiographs in adults followed
long-term for metatarsus adductus demonstrate obliquity of the medial
cuneiform-metatarsal joint.

Flexible actively correctable metatarsus adductus does
not require treatment. About 90% of metatarsus adductus is flexible and
actively correctable. These cases correct spontaneously during the
first 2 years of normal growth and development. Reassurance and
education for the parents about the natural history of the deformity is
indicated.

Treatment of the passively correctable metatarsus
adductus is controversial. Some authors recommend observation of the
foot and reassurance and education for the parents because many of
these feet will correct without intervention. Other authors recommend
that the passively correctable foot with metatarsus adductus can be
treated by passive stretching exercises of the foot by the child’s
parents. The exercises are performed by holding the heel in one hand
and pushing the forefoot outward to correct the C-shape of the foot.
The foot is stretched in this manner for about 3 seconds and repeated 5
times. The exercises can be easily performed at each diaper change.
Reverse last shoes can be used to maintain correction. Although
exercises and reverse last shoes are commonly used, their efficacy has
not been proven.

Rigid metatarsus adductus or partly correctable
metatarsus adductus that has failed an attempt at stretching exercises
for 3 months can be treated with serial manipulation and casting.
Short-leg or long-leg casts have both been used successfully. Casts are
removed and the foot is remanipulated at 1- to 2-week intervals until
the convexity of the lateral border of the foot is straightened.
Correct molding of the cast is very important. After application of the
plaster, molding is performed with the lateral fulcrum at the
calcanealcuboid joint. The calcaneus is pushed medially and the
forefoot is pushed laterally. Once correction is achieved, reverse last
shoes can be used to maintain the correction. Adding a Denis Browne bar
to the reverse last shoe is not recommended because of the tendency

of
the bar to produce correction through the subtalar joint resulting in
hindfoot valgus and a flatfoot. Casting is reported to be most
effective in children younger than 8 months of age; however,
improvement has been reported in children as old as 2 years of age. A
Wheaton brace, a removable plastic version of a stretch cast, is also
an option.

A simple method of documenting the metatarsus adductus
at presentation and documenting the changes in the shape of the foot
over time during observation or active treatment involves taking
photocopies of the foot in the weightbearing position.

Rare cases of rigid metatarsus adductus may benefit from
surgical correction. Surgical indications include the rigid foot that
has failed serial casting and the older child who presents with fixed
adduction deformity and shoe-fitting problems.

Multiple surgical procedures have been reported for
treatment of rigid metatarsus adductus. Outcomes are reportedly good in
most cases; however a standardized outcome measure does not exist.
Surgery can include tendon releases, joint releases, osteotomies or
combinations of any of these. In the young child the simplest surgical
procedure includes release of the abductor hallucis tendon with or
without capsulotomy of the first tarsometatarsal joint followed by
casting. Release of the tarsometatarsal joints of all five toes has
also been reported. However, reports of the development of degenerative
arthritis at the operated joints have tempered enthusiasm for this
once-popular operation. In the older child, metatarsal osteotomies can
be performed. Complications specific to this procedure include
cross-union of the osteotomies and iatrogenic closure of the proximal
first metatarsal physis. In the child older than 5 years of age, a
lateral closing wedge osteotomy of the cuboid combined with a medial
opening wedge osteotomy of the first cuneiform can be performed. The
graft from the cuboid can be used to hold the medial osteotomy open.

Casting for 4 to 8 weeks followed by bracing or wearing
reverse last shoes is commonly practiced following surgical correction
of metatarsus adductus. The recommended duration of bracing or special
shoe wear varies by author but can last for up to 2 years.

Clubfeet resistant to nonoperative treatment or those
with clubfeet secondary to neuromuscular or congenital condition often
require operative intervention. Surgery is generally done between 6 to
12 months of age. Multiple surgeries have been described for clubfoot
and many surgeons will tailor the procedure to the needs of the
individual, creating an “a la carte” approach to clubfoot surgery.
Multiple incisions have also been described for the surgery. The two
most commonly used incisions are:

All procedures can be adequately performed through
either approach; in all cases, this phrase applies: “the decision (of
which structures to release) is more important than the incision.”

A comprehensive clubfoot release includes the following four components:

Internal fixation may be used to help stabilize the foot
after surgery, particularly after more extensive releases. Typically, a
smooth 0.062-inch Kirschner wire is used to transfix the talonavicular
joint for 4 to 6 weeks. Postoperative casting and care varies.
Generally some type of bracing is used after surgery, but the type and
duration varies widely from surgeon to surgeon.

Complications of surgery are numerous. They include:

Treatment of these complications is difficult, and must
be individualized. Repeat soft tissue releases, tendon transfers,
osteotomies, and fusions may all be used alone or in combination to
treat the recurrent, residual, or overcorrected clubfoot.

The treatment of a congenital vertical talus is almost
always surgical. Casting is applied usually for stretching of the
anteriorly contracted structures. Surgery is usually indicated before
walking age, around 9 to 12 months of age.

The normal anatomy (Fig. 4.4-1)
of the hindfoot is complicated. The two bones below the ankle joint lie
on top of each other—the talus above and the calcaneus below. They meet
at the subtalar joint, which has three facets—posterior, middle, and
anterior. Distal to this are two bones that lie side by side: the
navicular on the medial side and the cuboid on the lateral side. The
anterior calcaneus articulates with the cuboid, and the anterior talus
articulates with the navicular.

The most common coalitions are seen between the talus
and calcaneus (i.e., bridging the middle facet) and between the
calcaneus and the navicular (which do not normally form an
articulation).

The overall exam should begin with appropriate history,
noting any problems at birth and the age at which the onset of
ambulation began. Clinically, one should evaluate rotation of the hips,
tibial/malleolar torsion, foot deformities (i.e., metatarsus adductus),
joint laxity, limb lengths (a flat, pronated foot may indicate a
compensatory mechanism to lower or shorten a longer limb), tightness of
Achilles tendon, Hubscher maneuver (discussed later), foot callosities,
shoe wear patterns, patellar position, and forefoot to hindfoot
relationships.

Painless, flexible flatfeet require no treatment.
Flexible flatfeet that ache may be managed with orthoses. Orthoses are
contraindicated in flexible flatfeet with a tight Achilles tendon, as
raising the arch exacerbates the underlying problem. Treatment in this
case is stretching the Achilles tendon through physical therapy or
casting. Rigid flatfeet may respond temporarily to orthoses but are
more likely to require surgical treatment to correct the underlying
defect or deformity. Various osteotomies of the hindfoot and midfoot
have been described to correct bony deformity. Arthrodesis is rarely
indicated in children and is used primarily as a salvage procedure in
cases of severe subtalar joint arthrosis.

Congenital hallux varus is a rare deformity and is
bilateral in one-third of cases. It is classified as either primary or
secondary. Primary congenital hallux varus is a supernumerary cartilaginous toe anlage presenting on the medial aspect of the foot (Fig. 4.6-1). It is not associated with any other anomalies.

Secondary congenital hallux varus
is associated with other anomalies especially polydactyly, true
metatarsus varus, and dysplasia of bone such as dystrophic dwarfism and
Apert syndrome. In secondary congenital hallux, the first metatarsal is
broad and shortened. It is often associated with bracket epiphysis.

Surgery for this condition must be tailored to meet the
needs of the individual deformity. In both types, it is important that
sufficient skin be maintained medially to ensure complete correction.
Sometimes it is necessary to develop a flap to lengthen the shortened
medial side. All the structures medially, including a metatarsal
phalangeal joint capsule and the abductor halluces must be released to
obtain complete correction. If associated with bony deformities of the
distal phalanx (Fig. 4.6-2), an osteotomy is required to prevent recurrence of the deformity.

Congenital hallux valgus,
the result of deformity of the distal phalanx of the great toe, is
deviated laterally toward the second toe at the interphalangeal joint (Fig. 4.6-3). It is

associated with syndromes and is also seen in neurologic conditions
such as cerebral palsy. Treatment is indicated with severe deformities
that result in callus and nail problems. In the younger individual, a
wedge resection of the proximal phalanx is done to realign the toe. In
the older child, an interphalangeal joint fusion is required because of
the adaptive changes that occur at the interphalangeal joint.

Mallet toe is a result of a flexion deformity of the
distal interphalangeal joint and usually involves a single toe. It is
usually asymptomatic in young children, but can become painful in
adolescence with shoe wear leading to corns as the toe strikes the sole
of the shoe. In infancy treatment consists of stretching and adhesive
strapping to the adjacent toes. Sectioning of the long flexor can treat
more severe deformities, especially on the second or third toe if the
deformity is still flexible. A fusion of the distal interphalangeal
joint is required in the mature foot with a rigid deformity.

Congenital hammertoe is a flexion deformity of the
proximal interphalangeal joint. Hammertoe deformity is congenital in
origin and often familial. It will often become symptomatic by causing
pressure on the dorsum of the toe by the shoe. Treatment in the infant
consists of stretching exercises in conjunction with adhesive strapping
in corrected position. Flexor tendon transfer can be done in a flexible
deformity in the preadolescent and adolescent. Any fixed deformity
requires fusion of the interphalangeal joint. A flexor tenotomy is also
required in the rigid deformity.

Claw toe deformities are the result of muscle imbalance.
The distal and proximal interphalangeal joints are hyperflexed and the
metatarsophalangeal joint is hyperextended and often dorsally
subluxated. All toes are usually involved in contrast to a mallet toe.
Claw toes are associated with cavus feet seen in neurologic conditions
such as Charcot-Marie-Tooth disease, cerebral palsy, and polio; or as
residuals of compartment syndrome. The condition is listed as
idiopathic only after a thorough search for known etiologies.

Conservative treatment consists of orthotics to elevate
the metatarsal heads. Surgical treatment requires correction of any
hindfoot deformity before proceeding with correction of the forefoot.
Flexor tendon transfer to the dorsum of the toe (Girdlestone-Taylor
procedure) along with extensor tenotomies and metatarsophalangeal joint
capsulotomy are used in flexible deformities. In fixed deformities, a
resection of the distal proximal phalanx with extensive dorsal
capsulotomies is preferred. The proximal interphalangeal joint is fixed
with a Kirschner wire for 6 weeks to maintain alignment while soft
tissue healing occurs and stabilizes the digit. In the great toe, the
Jones procedure and arthrodesis of the interphalangeal joint and a
transfer of the extensor hallucis longus to the first metatarsal is
used to align the toe.

This is often a manifestation of a generalized disease
such as neurofibromatosis, hemangiomatosis, lipomatosis, and
arteriovenous fistula. It can be part of the Proteus syndrome and
Klippel-Trenaunay-Weber syndrome. Localized gigantism most frequently
involves the second and third toes and the accompanying metatarsal. The
soft tissue is enlarged with tissue of the primary disease. Magnetic
resonance imaging can be used to distinguish localized macrodystrophia
lipomatosis from other conditions causing local gigantism. In
lipomatosis there is an increase in fibrofatty tissue, bony
hypertrophy, and fatty infiltration of muscle. In neurofibromatosis
there is fibrofatty infiltration of neural fascicles.

Surgical treatment requires evaluation of toe deformity
as well as the systemic disease associated with it. The major objective
of surgery is to reduce the size of the foot to improve function and
cosmesis. For a single toe, early epiphysiodesis can be used to control
some of the growth. Epiphysiodesis is unpredictable and resection of
middle or distal phalanx is often indicated to shorten the digit.
Amputation or ray resection is indicated for severe enlargement,
multiple previous failed procedures, and in the insensate toe.
Amputation of a toe should be exercised with care in localized
gigantism as secondary deformities have been described. Amputation of
the second toe may lead to development of hallux valgus. In some cases,
partial toe amputation can help with shoe wear. Complications such as
skin necrosis, infection, and recurrence are common.

Congenital curly toe is the most common congenital deformity of the lesser toes (Fig. 4.6-4).
It is usually bilateral and has a high familial incidence. It commonly
involves the lateral three toes. The toe is deviated medially under the
adjacent medial toe. It is considered to be secondary to a hypoplasia
of the intrinsic muscles. Curly toe is usually asymptomatic. In the
infant, strapping has been found ineffective. Severe deformities can be
treated either by a tenotomy of the flexion digitorum longus and flexus
digitorum brevis or a Girdlestone-Taylor tendon transfer. Contracted
deformity will often require an osteotomy of the phalanx. In contrast
to congenital overlapping toe, surgery is less frequent, but still
requires special attention to the available skin.

Congenital overlapping (digitus minimus varus) is commonly seen with the fifth toe overlapping the fourth toe.

There is dorsiflexion of the metatarsus phalangeal joint with abduction external rotation of the digit (Fig. 4.6-5).
The condition is usually bilateral and is also familial. In contrast to
congenital curly toe, this condition is symptomatic and can cause
problems with shoe wear. Early treatment requires stretching of the
medial ligaments and structures and the dorsal medial capsule. Taping
is done in the correct position. Surgery, however, is the definitive
treatment. Lengthening of the extensor tendons and dorsal and plantar
capsulotomies are often required. The skin incision must be carefully
planned as it is also contracted. Amputation is not recommended because
it results in pain and pressure on the metatarsal head.

Polydactyly refers to
supernumerary digits of the foot. Postaxial (fibular) polydactyly is
transmitted as an autosomal dominant trait and may be associated with
polydactyly of the hand. It is more common in African Americans,
occurring at a rate as high as 1 in 100. Preaxial polydactyly occurs on
the tibial side and is more common among Caucasians. Morphologically,
polydactyly may present as:

Surgical treatment is indicated for difficulty in
fitting and wearing shoes. The optimum age for surgery is 9 to 12
months, when the child is beginning to walk. Two principles are
important in performing any surgery on a multidigited foot:

The duplicated phalanx is usually excised and its
accompanying metatarsal can be narrowed if the head is too large or
duplicated.

On the medial side, adequate soft tissue and bone must
be removed. Polydactyly of the first ray is often accompanied by
congenital hallux varus and a bracket epiphysis. Excision of the medial
ray, lengthening of the abductor, and plication of the adductor into
the metatarsophalangeal capsule of the first ray is recommended. If
there is significant accompanying varus of the first ray,
syndactylization of the first and second toes may be necessary.

Congenital webbing of the toes does not usually lead to
a functional problem. It is most common between the second and third
toes. It is ten times more common in whites than blacks and may be
associated with polydactyly, brachydactyly, phalangeal fusion, and
annular bands. It can be seen as an isolated anomaly or as part of a
syndrome. Surgery is rarely indicated, but when it is necessary, the
same principles and techniques for surgical separation of syndactyly of
the hand apply.

Temtamy and McKusick classified isolated syndactyly into five types. These three are seen in the feet:

Syndactyly may be a predominant feature in Poland
syndrome, Apert syndrome, and other forms of acrocephalosyndactyly. It
is an occasional feature in chromosomal abnormalities such as Down
syndrome, trisomy 18, and Cri-du-Chat syndrome. Syndactyly is also seen
in Möbius, Silver, Cornelia de Lange, and Prader-Willi syndromes.

Treatment is indicated because shoe fitting is often a
problem and peers often ridicule children with webbed feet. In the
foot, treatment is indicated in syndactyly associated with polydactyly
and fusion of the metatarsals. Treatment is aimed at reconstruction of
the commissure and reconstruction of the digits. The incision is never
linear and consists of a series of flaps with use of skin graft where
necessary.

Ingrown toenail problems in children are rare and are
due to hypertrophy of the nail folds, hypertrophy of the nail bed, and
hypertrophy of the distal pulp. Hypertrophy of the lateral nail folds
results in tissue overgrowth over the nail and occludes the nail
groove. In resistant cases, a resection of 50% of the nail and
resection of lateral nail wall usually solves the problem. In severe
cases wedge resections of the lateral nail fold can open up the nail
groove. In the infant, the nail can be so sharp that it can grow
directly into a hypertrophied distal pulp. Massaging the bulbous tip
underneath the nail is sometimes useful and its recurrence can be
prevented by the use of appropriate size shoes and socks. Some genetic
disorders with nail changes are the nail-patella syndrome
characterized by lunula, and atrophy of the nail. A dislocating
hypoplastic patella, iliac horns, hypermobility, and dislocated radial
heads also characterize this autosomal dominant condition. Darier disease
is an autosomal dominant condition with distal subungual wedge-shaped
keratosis, red and white longitudinal striations, and thinning of the
nail bed. Pachyonychia congenita is
characterized by massive hypertrophy of the nail plates with a brown
and yellowish discoloration. It is also an autosomal dominant
condition. Dyskeratosis congenita is an
Xlinked recessive or autosomal dominant condition with atrophy of the
nail plate and ridges and fusion of the proximal nail fold. Deafness, onycho-osteodystrophy, mental retardation (DOOR) syndrome is an autosomal recessive disorder with anonychia or atrophied nails.

Streeter dysplasia is a spectrum of deformities thought
to be secondary to a rupture of the amnion and results in bands of
tissue that wrap around the fetus’ extremities in utero. Four types of constriction band deformities are described:

Distal rings are more common, as is involvement of the central digits.

Treatment is indicated in the deep rings that cause
interference with circulation. If the ring is circumferential, a staged
procedure relaxing half the band at a time is preferred. The ring is
excised down to normal tissue and multiple Z-plasties are performed to
ensure adequate skin coverage. Acrosyndactyly should be treated early
because all the digits are fused at the tip and can result in
deformities if left untreated.