Talipes calcaneovalgus is a foot deformity that is relatively commonly observed in newborns. It is characterized by dorsiflexion and a valgus position of the foot. Some categorize it as flexible flatfoot and contrast it with rigid flatfoot, i.e. vertical talus, which involves bone dislocation. Treatment does not usually require surgery; stretching exercises and massaging are adequate in mild cases, whereas splinting, high-top shoes or casting may be applied in more severe cases.
Talipes calcaneovalgus is a foot deformity encountered fairly frequently in neonates. Its incidence is around 4 cases per 10,000 newborns [1], but less severe cases may occur as frequently as in 5% of newborns [2]. Girls are affected more frequently than boys, and the condition can appear in one leg or both [3]. Predisposing factors are being a first-born, and breach delivery [1]. Together with irregularities in the digits, vertical talus, clubfoot, and metatarsus adductus, it represents the most prevalent foot problem apparent in the examination of the newborn.
The nomenclature of the foot deformities is somewhat ambiguous. The term clubfoot is used by some as the equivalent of talipes equinovarus (the sensu stricto clubfoot, a condition with plantar flexion and other characteristics). Others describe ”clubfoot” as a group of irregularities that include talipes calcaneovalgus (with dorsal flexion) and metatarsus adductus (with forefoot involvement only), in addition to talipes equinovarus. Congenital talipes calcaneovalgus is categorized as a positional talipes because the deformity is determined by the position of the foot pressed against the wall of the uterus.
Talipes calcaneovalgus is characterized by dorsal flexion of the foot, sometimes to an extreme degree, such that the toes touch the anterior tibia. The foot cannot be plantar-flexed beyond 90 degrees, and often is flexed to less than 90 degrees. In addition, the calcaneus is rotated externally, the feet are everted, the Achilles tendon is stretched, and the muscles of the leg are taut [4]. The ‘up and out’ appearance of talipes calcaneovalgus is the opposite of the ‘down and in’ presentation of talipes equinovarus – i.e. clubfoot in the narrow sense. Hence the name “reverse clubfoot” occasionally emerges for talipes calcaneovalgus [5]. Talipes calcaneovalgus must be differentiated from congenital vertical talus [6].
Foot deformities are discovered in the newborn by careful examination of both feet. Even the skin can reveal unusual tightness in cases of abnormality, but an important part of the examination is testing for the movements of the joints. In talipes calcaneovalgus, the plantarflexion is markedly limited; however, the dorsiflexion can, to some extent, be rectified by gently stretching the foot. In contrast, congenital vertical talus, which can be misdiagnosed for talipes calcaneovalgus, and which is characterized by a rigid bone dislocation, is not correctable.
Radiographs are used to verify the diagnosis and for differentiating talipes calcaneovalgus from congenital vertical talus. On lateral radiographs, the first metatarsal aligns with the talus bone in case of a talipes calcaneovalgus foot, whereas the axis of the talus is plantar to that of the first metatarsal in the congenital vertical talus condition.