Congenital Vertical Talus

The left foot of this 4-month-old boy has a convex sole with a rocker-bottom appearance, hindfoot equinus, and midfoot and forefoot dorsiflexion. This is the typical appearance of congenital vertical talus. This deformity is usually rigid; the midfoot cannot be brought into proper alignment with the hindfoot. The entire foot appears to be in a pronated or valgus position. The head of the talus may be prominent and can be palpated on the medial and plantar aspects of the foot.

Congenital vertical talus is relatively uncommon, with an incidence of approximately 1 in 10,000 live births. It occurs with equal frequency in both sexes and is bilateral in approximately 50% of cases. Although idiopathic deformities occur, most are associated with an underlying disorder, such as trisomies 13 through 15 and 18 syndromes, arthrogryposis multiplex congenita, or myelodysplasia.¹ Thus, a very careful musculoskeletal and neurologic evaluation is necessary in all infants and children with this deformity.

Physical examination. It is important to distinguish congenital vertical talus from the more common calcaneovalgus of the newborn and from idiopathic flatfoot.

Radiographic evaluation. Obtain AP and lateral weight-bearing radiographs or simulated weight-bearing radiographs of the foot, as well as a lateral view with the foot in maximum plantar flexion. The hindfoot equinus and vertically oriented talus are recognizable in the lateral view. The plantar flexion lateral view can demonstrate the inability of realigning the midfoot (navicular) with the hindfoot (talus). (The long axis of the talus and first metatarsal are parallel in a normal foot.) However, keep in mind that the navicular is not seen on radiographs in infants and young children, because it does not ossify until age 3 or 4 years.

Management. All infants with congenital vertical talus require a trial of serial manipulation and casting.¹ The midfoot and forefoot may be cast in a plantar-flexed position in an attempt to reduce the dislocated navicular onto the head of the talus; however, this is rarely successful.

Improvement must be confirmed radiographically.

The majority of children with this deformity require surgery to achieve satisfactory alignment. This entails an extensive one-stage soft tissue release.^2-5 In some children, tendon transfers may be necessary to achieve muscle balance.⁵ The results of surgical intervention are relatively good, although some children may require an orthosis to maintain proper alignment during the early phase of growth and development.

References:

REFERENCES:1. Drennan JC. Congenital vertical talus. The American Academy of Orthopaedic Surgeons Instructional Course Lecture. J Bone Joint Surg. 1995;77A:1916-1923.
2. Kodros SA, Dias LS. Single-stage surgical correction of congenital vertical talus. J Pediatr Orthop. 1999;19:42-48.
3. Duncan DR, Fixsen JA. Congenital convex pes valgus. J Bone Joint Surg. 1999;81B:250-254.
4. Stricker SJ, Rosen E. Early one-stage reconstruction of congenital vertical talus. Foot Ankle Int. 1997;18:535-543.
5. Mazzoca AD, Thompson JF, DeLuca PA, Romness MJ. Comparison of the posterior approach versus the dorsal approach in the treatment of congenital vertical talus. J Pediatr Orthop. 2001;21:212-217.