An intrauterine developmental malformation with a genetic component affecting the talus and resulting in medial and plantar deviation. Clubfoot is part of multiple syndromes.
Varies according to the racial group. One study reported an incidence of 1:1,000 in Caucasians, 7:1,000 in Polynesians, and 0.5:1,000 in Japanese. Bilateral cases occur in 40%. The male-to-female ratio is approximately 2.5:1.
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.
In some cases, electron microscopy has shown some evidence of neurogenic muscle disease, suggesting an innervation defect.
Deformity of the talus with medial and plantar deviation of its neck. The ankle joint mortise is normal, and foot deviation follows the talar neck deformity.
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 mortise. 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 mortise, and contracted and hypoplastic calf muscles.
Precautions before anesthesia
Search for evidence of coexistent diseases, such as Myelomeningocele, ☞Chondrodysplasia Punctata, ☞Arthrogryposis Multiplex Congenita, ☞Neurofibromatosis Generalisata, and others. If clubfoot is an isolated finding, routine preoperative assessment is considered adequate.
Anesthesia may be performed with general, regional, or combined techniques. A regional anesthesia 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 (type I fiber predominance in 24% of patients, nonspecific congenital myopathy in 24%, congenital myotonic dystrophy in 12%, mild spinal muscular atrophy in 5%, and mild congenital muscular dystrophy in 5%). This high rate of myopathic changes suggests regional anesthesia techniques may be preferred to prevent possible problems related to malignant hyperthermia and/or rhabdomyolysis and exaggerated hyperkalemia.
It has been recommended that MH-triggering drugs should best be avoided in patients with clubfeet. Due to the high rate of (often subclinical) myopathy, nondepolarizing neuromuscular blockers should be used with peripheral nerve stimulator guidance.