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An intrauterine developmental malformation with a
genetic component affecting the talus and resulting in medial and plantar
deviation. Clubfoot is part of multiple syndromes.
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Varies according to the racial group. One study reported
an incidence of 1:1000 in Caucasians, 7:1000 in Polynesians, and 0.5:1000 in
Japanese. Bilateral cases occur in 40%. The male-to-female ratio is
approximately 2.5:1.
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It is thought to be due to the action of a
major gene with additional contribution of multifactorial inheritance.
Autosomal dominant inheritance has been suggested.
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In some cases, electron microscopy has shown some
evidence of neurogenic muscle disease, suggesting an innervation defect.
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Deformity of the talus with medial and plantar deviation
of its neck. The ankle joint mortice is normal, and foot deviation follows
the talar neck deformity.
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Medial and plantar deviation of one or both feet
(pes adductus, equinovarus, supinatus) can be diagnosed by ultrasound in
utero. Postnatally, radiographic evaluation requires weight-bearing or
simulated weight-bearing anteroposterior and lateral radiographs of the
foot. The talus deformity consists of hypoplasia with plantar and medial
deviation of the shortened talar neck with lateral rotation in the ankle
mortice. Radiographs show medial subluxation of the navicular bone, which
articulates with the medial aspect of the talus neck. Medial subluxation of
the cuboid bone on the calcaneus head results in medial midfoot
displacement. Additional findings include shortening and contractures of
ligaments and joint capsules around the ankle mortice, and contracted and
hypoplastic calf muscles.
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Search for evidence of coexistent
diseases, such as Myelomeningocele, Chondrodysplasia Punctata,
Arthrogryposis Multiplex Congenita, Neurofibromatosis Generalista, and
many others.
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Anesthesia may be performed with
general, regional, or combined techniques. A regional approach may be
preferred in the presence of a myopathy. Combined neurologic,
electromyographic, and muscle biopsy studies show myopathic changes in up
to 70% of clubfoot patients. This high rate of myopathic changes suggests
regional anesthesia techniques may be preferred to prevent possible problems
related to malignant hyperthermia.
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Careful use of succinylcholine and
nondepolarizing neuromuscular blockers in the presence of myopathy and the use
of a peripheral nerve stimulator is recommended.
Chapman C, Stott NS, Port R, et al: Genetics of club foot in Maori and
Pacific people.
J Med Genet 37:680, 2000.
[PubMed: 10978359]
Wang J, Palmer RM, Chung CS: The role of major gene in clubfoot.
Am J Hum Genet 42:772,
1988.
[PubMed: 3358425]
Zanette G, Manani G, Pittoni G, et al: Prevalence of unsuspected myopathy
in infants presenting for clubfoot surgery.
Paediatr Anaesth 5:165, 1995.
[PubMed: 7489436]