The most common congenital disorder of the lower extremities, clubfoot, or talipes, is marked primarily by a deformed talus and shortened Achilles tendon, which give the foot a characteristic clublike appearance. In talipes equinovarus, the foot points downward (equinus) and turns inward (varus), and the front of the foot curls toward the heel (forefoot adduction).
Clubfoot, which has an incidence of about 1 per 1,000 live births, usually occurs bilaterally and is twice as common in boys as it is in girls. It may be associated with other birth defects, such as myelomeningocele, spina bifida, and arthrogryposis. Clubfoot is correctable with prompt treatment.
A combination of genetic and environmental factors in utero appears to cause clubfoot. Heredity is a definite factor in some cases, although the mechanism of transmission is undetermined. If a child is born with clubfoot, his sibling has a 1 in 35 chance of being born with the same anomaly. Children of a parent with clubfoot have 1 chance in 10.
In children without a family history of clubfoot, this anomaly seems linked to arrested development during the 9th and 10th weeks of embryonic life, when the feet are formed. Researchers also suspect muscle abnormalities, leading to variations in length and tendon insertions, as possible causes of clubfoot.
Signs and symptoms
Talipes equinovarus varies in severity. Deformity may be so extreme that the toes touch the inside of the ankle, or it may be only vaguely apparent.
In every case, the talus is deformed, the Achilles tendon shortened, and the calcaneus somewhat shortened and flattened. Depending on the degree of the varus deformity, the calf muscles are shortened and underdeveloped, with soft-tissue contractures at the site of the deformity. The foot is tight in its deformed position and resists manual efforts to push it back into normal position.
Clubfoot is painless, except in older, arthritic patients. In older children, clubfoot may be secondary to paralysis, poliomyelitis, or cerebral palsy, in which case treatment must include management of the underlying disease.
An early diagnosis of clubfoot is usually no problem because the deformity is obvious. With subtle deformity, however, true clubfoot must be distinguished from apparent clubfoot (metatarsus varus or pigeon toe).
Apparent clubfoot results when a fetus maintains a position in utero that gives his feet a clubfoot appearance at birth. This can usually be corrected manually.
Another form of apparent clubfoot is inversion of the feet, resulting from the peroneal type of progressive muscular atrophy and progressive muscular dystrophy. With true clubfoot, X-rays show superimposition of the talus and the calcaneus and a ladderlike appearance of the metatarsals.