Congenital Talipes Equinovarus or Club Foot

Congenital talipes equinovarus or club foot or CTEV as it is often known as is a congenital deformity affecting single foot or both. Club foot may result from a bony, a muscular or a neuropathic error, or maybe termed idiopathic. Idiopathic club foot is the most frequent and unless specified otherwise, the term congenital talipes equinovarus represents an idiopathic type.

In this deformity, the foot is fixed in adduction, supination and varus resulting in inwardly inclined and downward pointing foot.

Four elements of deformity are

• Flexion of the ankle
• Inversion of the foot
• Adduction of the forefoot
• Medial rotation of the tibia.

The first metatarsal is more plantarflexed.

Clubfoot was described by Hippocrates around 400 BC.

Joint laxity, congenital dislocation of the hip, tibial torsion, ray anomalies of the foot, absence of some tarsal bones and a history of other foot anomalies in the family is found to be associated with club foot.

The incidence of clubfoot is approximately 1 case per 1000 live births. Males are twice as commonly affected as females.

Bilateral involvement is seen in 30-50% of cases.

Pathophysiology of Clubfoot

The exact cause of congenital talipes equinovarus is not known but there is strong evidence for genetic and environmental factors. There is evidence that development of bone, joint, connective tissue, innervation, vasculature and muscle may each be implicated in the pathophysiology.

Various theories of the pathogenesis of clubfeet have been advanced, including the following:

• Arrest of fetal development in the fibular stage
• Defective cartilaginous anlage of the talus
• Neurogenic factors
• Retracting fibrosis
• Anomalous tendon insertions
• Seasonal variations

Most infants who have clubfoot have no identifiable genetic, syndromal, or extrinsic cause.

Extrinsic associations include teratogenic like sodium aminopterin, oligohydramnios, and congenital constriction rings.

Changes in Foot and Leg in Club Foot

The typical congenital clubfoot is at first deformity of soft tissue only. The essential features are plantar flexion of the talus, inversion of the calcaneus and adduction of the forefoot.

At birth, the bones of the foot are normal in shape but altered in position. Over the skin on the outer part of the foot there are usually dimples which may be so marked as to resemble scars.

The lateral malleolus is prominent. The medial appears flattened and poorly developed.

Soft Tissue Changes

The muscles are poorly developed and the tendons attenuated. The tendocalcaneus passes downwards and inwards to its insertion into the calcaneus, while the plantar muscles, especially on the medial side, are contracted. The anterior muscles of the leg are elongated. Factors related to muscle anatomy include the following:

Thickening of the tendon sheaths frequently is present, especially of the tibialis posterior and peroneal sheaths. Contractures of the posterior ankle capsule, subtalar capsule, and talonavicular and calcaneocuboid joint capsules commonly are seen.

Contractures are seen in the calcaneofibular, talofibular, (ankle) deltoid, long and short plantar, spring, and bifurcate ligaments. The plantar fascial contracture contributes to the cavus, as does contracture of fascial planes in the foot.

The ligaments on the medial and inferior surfaces of the talocalcaneonavicular joint are contracted, the plantar calcaneonavicular ligament being very small and short. The deltoid ligament of the ankle joint is similarly affected.

Atrophy of the leg muscles, especially in the peroneal group, is seen in clubfeet

The number of fibers in the muscles is normal, but the fibers are smaller

The triceps surae, tibialis posterior, flexor digitorum longus (FDL), and flexor hallucis longus (FHL) are contracted

The calf is smaller and remains so throughout life, even after successful long-lasting correction of the feet

Changes in Bones

Bony changes appear as a result of the long-continued contraction of the soft parts. They are at first confined to the talus, but subsequently, the calcaneus, the navicular and the cuboid become appreciably altered.

Talus becomes prominent on the dorsum of the foot, broadens and in severe cases becomes an obstacle to passive dorsiflexion of the foot even after the soft structures have been stretched or divided.

The head and neck of the talus are deflected downwards and medially, carrying the navicular and the forefoot with them. The talar neck is often shortened. The head and neck relative to the axis of the body is reduced from the normal 150 degrees.

The articular surfaces of the talar head are wedges and displaced medially so that the talar navicular joint line lies out of the coronal plan towards the sagittal. The navicular is medially displaced, even dislocated, from its position in front of an abnormally directed talar head.

The calcaneus becomes tilted and so its medial tuberosity approaches the medial malleolus. Its vertical height is less on the medial side, and the anterior part of the bone deflected medially, following the direction of the neck of the talus. The posterior tubercle is displaced under the talus. The sustentaculum tali is often poorly developed.

The navicular and the cuboid are displaced inwards. The phalanges are plantar flexed.

Clinical Presentation of Congenital Talipes Equinovarus

When a child presents with club foot, detailed a detailed family history of clubfoot or neuromuscular disorders should be sought and a thorough general examination is performed to identify other abnormalities like myelomeningocele and arthrogryposis as similar deformities occur in these conditions.

The ankle is in equinus, and the foot is supinated (varus) and adducted. Dorsiflexion beyond 90° is not possible.

[A normal infant foot usually can be dorsiflexed and everted, so that the foot touches the anterior tibia).

The navicular and cuboid bone is medially displaced. Medial plantar soft tissue contractures are present. Calcaneus is found be in u and rotated so that anterior aspect is medialward and posterior aspect lateralward.

The heel is small and empty and soft to the touch.  It becomes firmer as it gets filled with treatment.

The neck of the talus is uncovered laterally [due to medial movement of navicular] and easily palpable in the sinus tarsi area.] The medial malleolus is difficult to palpate and is often in a proximity of the navicular. The normal navicular-malleolar interval is decreased.

There is supination of hindfoot but the forefoot is in relative pronation to hind foot.

There is the drop of the first metatarsal which creates a position of cavus.

The tibia often has internal torsion.

The leg is smaller and less well-developed than on the healthy side. The skin of the foot may be normal, though stretched and thin on the dorsum and thrown into creases along the medial border and on the sole.

There may be a sign of external pressure on the dorsum in the shape of scars. The head of the talus can be felt on the dorsum of the foot.

In many cases a well-marked genu valgum is present.

Bursae and callosities develop over the weight- bearing areas.

Imaging

Imaging is not needed to gauge the nature or the severity of the deformity but provides a useful baseline before and after correction of the feet

Radiographs can also confirm rocker bottom foot, a complication that can arise by forceful correction.

X-rays are also useful to rule out any bony abnormality like tibial hemimelia..

The weight-bearing dorsoplantar or anteroposterior foot radiograph is key to the assessment. In addition,  lateral radiographs are also done.

Where weight bearing is not possible, it should be simulated.

AP and lateral views also can be taken in full dorsiflexion and plantarflexion and are important in measuring the total amount of dorsiflexion achieved at the end of treatment, as well as the relative positions of the talus and calcaneum.

Talocalcaneal angle is measured in AP and lateral films by drawing lines through the center of the long axis of the talus and through the long axis of the calcaneum. Normal values are between  25-40°.

The angle less than 20° is considered abnormal.

In lateral view, lines are drawn through the midpoint of the head and body of the talus and along the bottom of the calcaneum. Normal values are 35-50°. In clubfoot, the values are between -10 and 35°

These two angles, AP and lateral, are added to derive the talocalcaneal index, which in a corrected foot should be more than 40°.

The AP and lateral talar lines normally pass through the center of the navicular and the first metatarsal.

A lateral film with the foot held in maximal dorsiflexion is the most reliable method of diagnosing an uncorrected clubfoot.

Treatment

The objectives of successful treatment are

• Deformity correction
• Development of sufficient muscle power to maintain the correction.

Even after correction, the child needs to be under pronged constant supervision until the period of growth is over, as there is distinct tendency to retrogression.

The type of treatment varies with the age at which treatment begins.

The treatment should be begun as early as possible.

Treatment of congenital talipes equinovarus has undergone a significant shift after Ponseti’s work.

Recent studies have suggested that the Ponseti method has a definite edge over the traditional treatment approach and results in the lesser need for surgery.

Pirani Scoring System

Traditionally, two categories of clubfeet are identified, as follows:

• Easy or correctable clubfeet – These are readily corrected with manipulation, casting, and splintage alone
• Resistant clubfeet – These respond poorly to splinting and relapse quickly after seemingly successful manipulative treatment; they require early operative management and are said to be associated with a thin calf and a small high heel.

The Pirani scoring system can be used to identify the severity of clubfoot and also to monitor correction.

Pirani’s scoring system consists of six categories, three in the hindfoot and three in the midfoot, as follows –

Midfoot score

• Curvature of the lateral border (CLB) of the foot
• Medial crease (MC)
• Uncovering of the lateral head of the talus (LHT)

Hindfoot score

• Posterior crease (PC)
• Emptiness of the heel (EH)
• Degree of dorsiflexion (DF)

Each category is scored as 0, 0.5, or 1.

The lowest possible [best] total score for all categories combined is 0, and the highest possible [worst] total score is 6.

Traditional Nonoperative Treatment

Immediately after Birth

Manipulation, frequently repeated, but gently, is the method of treating the deformity in an infant. The infant lies supine on its mother’s lap, while she protects the knee, and prevents any strain from falling on the ligaments, by grasping the upper end of the tibia. While one hand fixes the heel, the other reduced the adduction of the forefoot. To do this, the thumb of one hand rests on the talus and acts as a fulcrum, while the other hand presses the forefoot into abduction. The maximum result is maintained for a few seconds at the sitting and should be repeated six times at each ‘nappy’ change.

This is continued for 10-15 days. By this time, the infants’ legs become shapely enough to apply corrective splints/casts. At this time,  the limb is immobilized, after correction, in splint or cast. The casts/splints are changed after 10-15 days to accommodate the growth of the limb.

The order of correction is as follows:

• Forefoot adduction
• Forefoot supination
• Equinus

Forceful correction of equines may lead to rocker bottom foot.

If full correction has not been achieved by 3 months, conservative management has failed and operative intervention is considered. While awaiting surgery, splintage will be continued to maintain any incomplete correction.

If the foot gets corrected, the patient is put on Denis Browne bar splint and when he starts walking Denis Browne shoes in the day and splint in the night.

Denis Browne splint is a splint that is worn on both the feet and connected by a bar. It takes the advantage of kicking motion of infant’s legs that kids do when they lie. It corrects deformity, prevents recurrence of deformity and at the same time encourages the activity which is so important for muscular development. Any residual deformity demands surgical correction.

The child is given DB shoes until about 7 years of age.

Ponseti method

Ponseti’s method includes manipulation followed by immobilization for some period, percutaneous tenotomy for final equines correction and then brace for holding the foot in corrected position.

The treatment is begun as soon as after birth [within 7-10 days] but in late cases can be done as long as deformity is correctable.

Ponseti’s method differs from traditional method in the order of deformity correction.

It considers the calcaneal internal rotation (adduction) coupled with plantarflexion as the key deformity.

The goal is to abduct the foot and dorsiflex it.

For this, the calcaneum should be allowed to rotate freely under the talus. Thus the correction is through a normal arc of the subtalar joint.

The foot is manipulated and a long leg cast is applied to hold the correction.

After maximal foot abduction is obtained, most cases require a percutaneous Achilles tenotomy.

After the manipulation and casting phase, the feet are fitted with open-toed straight-laced shoes attached to a Dennis Brown bar.

In 10-30% of cases, a tibialis anterior tendon transfer to the lateral cuneiform is performed when the child is approximately 3 years of age giving lasting correction of the forefoot, preventing metatarsus adductus and foot inversion. This procedure is indicated in a child aged 2-2.5 years with dynamic supination of the foot.

Surgery for Talipes Equino Varus

Traditionally, surgery for clubfoot is indicated when a plateau has been reached in nonoperative treatment. It is usually performed when the child is of sufficient size to allow recognition of the anatomy. No specific contraindications to surgery exist, though the child’s size dictates that surgery is best performed at approximately age 6 months. With greater acceptance of the Ponseti conservative technique, surgery has come to be seen to be a contentious issue. Surgery for clubfeet is no longer the only standard of care.

Soft tissue releases

The rationale for soft tissue release is that realignment of the talus, calcaneum, and navicular allows remodeling of the articular surfaces to occur.

Surgical treatment should take into account the age of the patient, as follows:

• In children younger than 5 years, correction can be achieved with soft-tissue procedures
• Children older than 5 years require bony reshaping (eg, dorsolateral wedge excision of the calcaneocuboid joint [Dillwyn Evans procedure] or osteotomy of the calcaneum to correct varus)
• If the child is older than 10 years, lateral wedge tarsectomy or triple fusion (arthrodesis) is required (salvage procedures)

Posterior release

If the forefoot adduction and heel varus are virtually corrected after conservative treatment, a posterior release can be performed.

Lengthening of the tendo Achillis and posterior capsulotomy of the tibiotalar and subtalar joint.

Posteromedial release [Turco]

• Lengthening tendocalcaneus
• Release of  flexor hallucis longus, flexor digitorum longus and tibialis posterior released
• Release of talofibular, calcaneofibular, and deep portion of deltoid ligaments release
• Release of distal tibial and fibular ligaments
• Posterior release of the subtalar joint
• Plaster-of-Paris cast in corrected position for 4 weeks, followed by splints until maturity

Circumferential release

Mckay based this procedure on the belief that abnormal rotation of the talus must be corrected effect this is a complete subtalar release.

Tendon transfer

A passively correctable deformity resulting from muscle imbalance may be resorted by transferring tendons

Tendon transfer is never indicated as primary treatment. Transfer of the tibialis anterior to the more lateral cuneiforms or fifth metatarsal may correct some of the deformity.

Osteotomy

In general, these procedures are carried out on residual deformity in order children.

• Dwyer’s opening wedge osteotomy of the calcaneus to correct residual varus deformity.

• The Dillwyn-Evans procedure –  The Dillwyn Evans procedure consists of a medial and posterior release together with excision and fusion of the calcaneocuboid joint. It should be reserved for patients older than 4 years.

Triple Arthrodesis

The arthrodesis is a salvage procedure for the stiff and painful foot. It is carried out after the skeletal age is at 12 years. At this stage, the rate of pseudarthrosis is reduced and undue shortening of the foot is avoided. These patients have almost always had previous surgery unsuccessfully.

Complications

• Infection (rare)
• Wound breakdown
• Stiffness and restricted range of motion –
• Avascular necrosis  of the talus
• Persistent intoeing

Prognosis

Approximately 50% of clubfeet in newborns can be corrected nonoperatively.

Patients report satisfactory results in 81% of cases.

Previous surgery seems to have a deleterious effect on the result.

Heavy and those who have jobs involving long periods on their feet were found to be more likely to have painful feet.

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