Congenital
deformities
This term is more accurate than the older congenital dislocation of
the hip (CDH) because it includes dislocation along with other less severe
forms, all of which have in common a dysplasia or natural shallowness of the
acetabulum. The femoral neck is usually anteverted.
There
is a wide spectrum of presentation of DDH from birth to adult life. The
condition can manifest as a neonate with clinical hip instability (Fig.
27.31),
an infant with limited abduction (Fig. 27.32), a limping toddler
(Fig. 27.33),
a
Incidence
This is highest in the neonate where environmental factors such as
breech presentation, transient ligamentous laxity and the skills of examiners
can influence the rate of detection of instability.
The incidence depends on the criteria by which the diagnosis is made. The rates of detection of neonatal instability in some series approach 20 per 1000 births, whereas the incidence of late presenting dislocations (after the age of 3 months) is generally in the order of 0.5—1 per 1000. The inference is that many cases will stabilise spontaneously and this creates a dilemma for the surgeon as to which cases should be treated
Aetiology
Many factors are related to DDH (Table 27.6). A family history of
DDH increases the risk up to 30 times. The condition is five times more common
in girls, possibly related to hormonal factors producing joint laxity.
The left side is affected more commonly than the right.
Breech
presentation, especially the extended
position, firstborn children and caesarean section are
associated with increased neonatal instability, possibly through restricted
foetal movement.
A
foot deformity or torticollis should also alert the examiner to
possible associated DDH. Finally, there may be hip dislocation or dysplasia in
association with neuromuscular disease syndromic conditions and skeletal
dysplasia.
Diagnosis
Neonate. The clinical examination is only part of the general
examination. All newborn babies should be screened for hip
The
specificity of clinical neonatal examination is 100 per cent (no false
positives). However, its sensitivity is much lower; even skilled examiners are
unable to eliminate late diagnosed cases.
Ultrasonography
is a valuable test. It is more sensitive than clinical examination and
can detect not only displacement of the femoral head but also varying degrees of
dysplasia. Therein lies its weakness for it tends to over diagnose the condition
and thus subject babies to unnecessary treatment. Also, it is very difficult to
deliver universal ultrasound screening to communities where the population is
mobile, the time in hospital is short, and obstetric and imaging services may be
geographically separated.
Radiography
can be helpful in the neonate provided
care is taken in positioning the patient. However, X-rays are not generally
reliable until approximately the age of 3 months (Fig.
27.36).
Infant.
The hips should be examined as part of routine developmental checks, looking in
particular for asymmetry, such as an extra thigh crease, shortening of a limb or
limitation of abduction (Fig. 27.32).
Child.
The child limps, the affected leg is externally rotated, there is an increased
lumbar lordosis, and there is regularly an extra thigh crease and limited
abduction. However, the signs may be subtle (Fig. 27.33) and easily
misinterpreted as part of normal development in an unsteady toddler. A bilateral
case is more difficult to diagnose because the gait is symmetrical. Indeed, the
condition may be missed until late in childhood.
Adolescent.
Pain is the usual feature and an X-ray will reveal dysplasia and possible
subluxation.
Adult.
Pain is again the usual complaint and X-rays may now show degenerative change as
well as dysplasia (Fig. 27.35).
Treatment
Although the details of treatment vary at different ages the principles
are the same (Table 27.7) and should all be considered before deciding which
one is appropriate for an individual case. The objective is a stable congruous
reduction through gentle methods so that the fragile growth plate is not
damaged. Such an event (avascular necrosis) is a major complication and usually
results in shortening, coxa vara and a greater trochanter, which is high
because its growth plate is not affected.
Infant.
Traction and surgery are not indicated. The hips can usually be reduced (Ortolani)
and should then be held in a harness or splint (Fig.
27.37) for about 8 weeks. A
harness allows movement but requires more supervision, and out of expert hands
carries a significant failure rate. A splint contains the hips better but
thereby carries a risk of avascular necrosis.
A
baby, for example, aged 6 months would usually require preliminary traction
followed by closed reduction augmented by soft-tissue release (psoas and/or
adductor).
An
arthrogram is often helpful to define the abnormal soft tissues and confirm a
satisfactory reduction.
Toddler
and young child. Although it is still possible to achieve reduction by closed
methods it becomes more likely that, with age, open reduction along with femoral
or innominate osteotomy will be required.
Open
reduction. This is usually undertaken through the anterior approach. The
iliac apophysis is split. The psoas is divided near its insertion. The capsule
is opened and excess trimmed. The ligamentum teres and soft tissues in the
acetabular floor are removed. The transverse ligament is divided. The inturned
labrum (limbos) may also need to be cut in a radial fashion to allow entry of
the femoral head. Reduction can then usually be achieved. However, in the
majority of cases it is necessary to complement the reduction with a realignment
femoral or innominate (Salter) osteotomy. If reduction is impossible because of
a high dislocation, femoral shortening along with realignment is necessary.
Postoperatively, the child is held in a cast for 6—8 weeks and then mobilised.
In
later childhood, dislocations can still be treated by the combination of open
reduction, femoral osteotomy and acetabuloplasty. However, the older the child the more difficult and
unrewarding the surgery becomes, especially in bilateral cases.
Adolescent
or young adult. Those presenting with a painful dysplastic hip may require
surgery. A realignment of the joint through pelvic or femoral osteotomy is only
appropriate if there is a congruous hip joint. Otherwise (i.e. subluxation)
the acetabulum has to be augmented by other means, for example shelf
arthroplasty.
Special
cases. DDH associated with neuromuscular disease, syndromic disorders or
skeletal dysplasia requires special thought. In such cases (e.g. arthrogryposis,
spina bifida) surgery is likely to fail through redisplacement or stiffness.
Therefore, it may well be in the child’s overall best interests to leave the
hip joint alone and restrict one’s surgery by treating major limb malalignment
by corrective osteotomy.
Coxa
vara
This is a descriptive term that describes a decrease in the angle
between the femoral neck and shaft. Many conditions can produce this deformity
but three general categories are recognised.
•
Congenital — this is present at birth and results in shortening of the
leg. It is often associated with femoral deficiency.
•
Developmental (infantile) — coxa vara develops in early childhood and
progresses with growth. The cause is likely to be related to defective
enchondral ossification in the metaphysis. Corrective osteotomy may be required.
•
Acquired — this group includes cases where the deformity is due to a
metabolic disorder (e.g. rickets), trauma (e.g. avascular necrosis in the
treatment of DDH) and infection.
Congenital
deformities of the feet
Congenital
t
If ever there was a condition which exemplified ‘Beauty and the
Beast’ this is it. The deformity can present over a wide spectrum of severity.
At one end there are postural forms which respond easily to simple
treatment; at the other there are severe fixed deformities which resist
treatment and behave in a beastly fashion.
Incidence.
This is generally quoted as one—two cases per 1000 babies.
Aetiology.
Although the majority of cases is idiopathic, the condition can regularly be
related to factors such as posture, heredity and associated conditions like
neuromuscular disease (Table 27.8 and Fig. 27.38).
The
risk of club foot is increased 20-fold if a first-degree relative has the
condition, and there ate examples of racial prevalence, for example among
Polynesians. The most difficult club feet tend to be in association with
neuromuscular, syndromic or dysplastic conditions.
Clinical
features. The baby must be fully examined because of the links between foot
deformity, hip disorder and other conditions. The diagnosis of club foot is
usually obvious. The hindfoot and forefoot are in equinus and varus (Fig.
27.39). However, the stiffness varies from case to case and it is important to
assess whether the deformity is likely to be postural or fixed (Fig.
27.40).
Mild postural cases may be corrected above the plantigrade position, whereas a
severe fixed deformity falls well short of this.
Pathological
anatomy. In fixed deformity the navicular dislocates medially and downwards
off the head of the talus, whose neck likewise becomes deformed in the same
direction. The front of the os calcis goes medially under the talus, whereas the
back of the os calcis is high and lateral, with tethers between it and the
fibula. Several tendons are tight (tendo achilles, tibialis posterior, flexor
hallucis longus, flexor digitorum longus) and there are contractures of joint
capsules and ligaments. Debate continues as to which of the changes in club foot
are primary and which are secondary.
Treatment.
This depends on stiffness. Mild cases will respond to stretching, whereas fixed
deformities will probably need surgery.
The
parents must be given careful explanation of the condition. They should
understand that club foot alone does not prevent a child walking, and even in
the untreated case function can be good (Fig. 27.41). However, the foot cannot
be made normal. It usually ends up smaller and stiffer and the calf is thinner.
Finally, parents must realise that relapse can occur and, therefore, follow-up
until maturity is necessary.
Most
babies with significant congenital talipes equinus varus (CTEV) undergo
stretching and strapping, usually supervised by a physiotherapist. Alternative
methods include serial casts or splints.
Surgeons
generally advise nonoperative treatment for 3 months when it is likely to be
clear whether soft-tissue surgery is needed. If so, persisting with stretching
and splintage is unlikely to remain effective. Indeed, persistent or over-vigorous
stretching may cause a breach in the midfoot to produce a rocker bottom
deformity which is very difficult to treat.
Primary
surgery. This can be undertaken at 3 months, but most surgeons prefer to
wait until after 6 months of age. In infants who are handicapped in other
ways, and whose prognosis for walking is unclear, it is wiser to wait
even longer.
The
operation depends on the severity of the condition. The structures to be
considered for division or lengthening are tendons (achilles, tibialis
posterior, flexor hallucis longus, flexor digitorium longus), joint capsules
(ankle, subtalar, calcaneocuboid, talonavicular, naviculocuneiform) and
ligaments (talofibular, calcaneofibular, talotibial, peroneal sheath, plantar
fascia).
The
surgical approach depends on what are to be divided. The posterior route alone
will suffice for most cases, whereas a pantalar release will require a more
extensive approach (e.g. Cincinnati). Temporary wires may be used to fix reduced
joints, especially the talonavicular. In very severe cases (e.g. arthrogryposis,
sacral agenesis) soft-tissue surgery alone will not correct the deformity. In
this event, talectomy may be indicated.
Postoperatively,
an above-knee cast is applied with the knee at a right angle and the foot as
dorsiflexed as the wound and the circulation will allow. The cast is changed at
2—3 weeks when further correction is gained. Difficult cases may need more
than one change. Plasters are retained for 8 weeks or so. Thereafter, continuing
splintage and supportive footwear may be needed according to severity.
Secondary
surgery. Recurrence of deformity (relapse) is, unfortunately, common in
severe cases and bony surgery is ultimately necessary.
However, most surgeons try to avoid such surgery in patients under the
age of 5 years. Meanwhile, repeat soft-tissue release and/or transfer of
the tibialis anterior tendon may hold the foot, at least temporarily.
Later
on, collateral release (division of medial structures combined with
calcaneocuboid fusion), wedge tarsectomy, triple arthrodesis, supramalleolar
osteotomy and the Ilizarov technique are possible salvage operations.
This is a rare condition, 100 times less common than club foot (Fig.
27.42). The hindfoot is in equinus with the talus vertical.
The
navicular is dislocated on to the neck of the talus and the combination gives
the appearance of a rocker bottom foot. However, unlike the deformity caused by
over-correction of club foot, the talus and os calcis retain a normal
relationship.
The
condition is regularly associated with neurological disorder. Surgical
correction is usually required and involves complex reconstruction of the foot.
Curly
toes
The third and fourth toes are usually affected and flexed at their
distal interphalangeal joints. The condition may correct spontaneously and
surgery (normally flexor tenotomy) should be delayed until after the age of 3
years, as for symptomatic toes.
Congenital
abnormalities of the knee
Patella
There is a number of congenital conditions involving the patella, which
may be absent or hypoplastic in association with the nail—patella syndrome.
Other features of the syndrome include hypoplasia and splitting of the nails,
elbow abnormalities and bony spurs on the ilium. The patella may be bipartite
and confused with a fracture; the separate ossicle is usually superolateral.
There may be congenital dislocation of the patella, which is small and fixed to
the lateral femoral condyle; a fixed flexion deformity of the knee and genu
valgum will be noted.
Discoid
meniscus
The lateral meniscus is almost always involved, and there is either a
complete discoid meniscus of normal mobility or the
Congenital
dislocation of the knee
The joint is hypo extended with the tibia displaced forwards on the
femur. Mild cases are postural and related to malpresentation (e.g.
extended breech). They can be treated by simple splintage or exercises. More
severe ones involve quadriceps contractures, which require surgical release (quadricep plasty).
Congenital
deformities of the fingers
Camptodactyly
This is a nontraumatic flexion deformity of the little finger at the
proximal interphalangeal joint. Most cases are better left alone as function is
usually normal.
Clinodactyly
This is a curvature of a digit in the radioulnar direction. It may be
associated with other syndromes.
Kirner’s
deformity
This affects the little finger in which there is radial and palmar
curving of the distal phalanx.