Congenital Clubfoot

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This 3-month-old boy has an untreated right clubfoot deformity. The foot is stiff and uncorrectable. The vertical midfoot crease indicates significant deformity. An anteroposterior (AP) simulated weight-bearing radiograph shows parallelism of the long axis of the talus and calcaneus; this indicates varus alignment of the hindfoot. There is also forefoot adduction.

This 3-month-old boy has an untreated right clubfoot deformity. The foot is stiff and uncorrectable. The vertical midfoot crease indicates significant deformity (A). An anteroposterior (AP) simulated weight-bearing radiograph shows parallelism of the long axis of the talus and calcaneus; this indicates varus alignment of the hindfoot (B). There is also forefoot adduction.

This is a typical case of congenital talipes equinovarus-or clubfoot-the most obvious of all childhood foot deformities, and one of the most common. It is easily diagnosed at birth by its characteristic appearance and soft tissue contractures. The incidence is 1 per 1000 live births; the condition is bilateral in about half of cases. The right side is involved more often than the left, and boys are affected twice as often as girls. Genetic factors are apparently involved, since the risk of a second child having this deformity in a family is about 5%.1 If a parent has a clubfoot, the risk per child will be approximately 25%.

Muscle and soft tissue biopsies and electromyographic studies show abnormalities that suggest a possible neuromuscular cause.2-6 This partially explains the foot-size discrepancy, calf hypoplasia, and mild lower extremity length discrepancy.

Physical examination. As its name suggests, the characteristic position of the foot resembles that of the head of a golf club; deformities include ankle equinus, hindfoot inversion (or varus), forefoot adduction, and variable rigidity. Positional clubfoot, in which the foot is flexible and its positioning is correctable, represents an in utero positional variation. It does not have the causative factors associated with a congenital clubfoot. Any child with a true congenital clubfoot requires a careful musculoskeletal and neurologic evaluation, since this deformity can be part of a more encompassing syndrome, such as arthrogryposis multiplex congenita.

Radiographic evaluation. Radiographs are not necessary for the diagnosis of clubfoot, but they are obtained as a baseline for assessing response to treatment. These include AP and lateral weight-bearing radiographs or simulated weight-bearing radiographs and a lateral film in which the foot is in maximum dorsiflexion (see B). The characteristic radiographic features of untreated clubfoot include ankle equinus, parallelism of the long axes of the talus and calcaneus (hindfoot varus), and forefoot varus and adduction.

Ultrasonography can help visualize the unossified cartilaginous tarsal bones of the foot, but it is not commonly used.7,8 In a clubfoot, the navicular, which does not ossify until 3 to 4 years of age, is subluxated medially on the head of the talus. Ultrasonography has also been used to diagnose clubfoot antenatally.8 This has led to consideration of treatment before delivery.

Management. Initial treatment consists of weekly manipulation and casting.9,10 This begins as soon after birth as possible. An affected infant should be referred to an orthopaedic surgeon before discharge from the newborn nursery. Initially, manipulation is directed at the foot deformity rather than the ankle plantar flexion (equinus). After each manipulation, the foot is immobilized in a long leg cast in the maximally corrected position. Weekly manipulation and casting continue until the foot is correct, both clinically and radiographically. The equinus is corrected last by stretching the Achilles tendon and posterior ankle structures.

The goal is to have the foot corrected clinically and radiographically by 3 months of age. The success rate has increased to 90% to 95% with the currently popular Ponseti technique.

Feet that correct with serial casting are managed with continued casting, an orthosis, or a Denis Browne splint. The last uses plates attached to the soles of an infant's shoes with a crossbar between them to hold the foot in the desired position.10

Clubfoot that is not completely corrected by age 3 months is best managed by surgical intervention when the child is between 6 and 12 months of age. Postoperatively, the foot is immobilized for 6 to 12 weeks. The child is allowed to walk on the foot immediately following removal of the last cast. An orthosis, corrective shoe, or Denis Browne splint may be used until he or she is walking well.10 The results of surgery are satisfactory in approximately 85% to 90% of children.11-13 However, all children with clubfoot need to be followed throughout growth and development, since residual muscle imbalance can lead to partial recurrence or additional deformities.

REFERENCES:
1.
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13. Huang YT, Lei W, Zhoa L, Wang J. The treatment of congenital clubfoot by operation to correct deformity and achieve dynamic muscle balance. J Bone Joint Surg. 1999;81B:858-862.