Review Question - QID 218726

Congenital vertical talus (CVT) presents as a rigid foot deformity due to an irreducible dorsolateral navicular dislocation that results in a vertically oriented talus. Diagnosis can be made with forced plantar flexion lateral radiographs showing persistent dorsal dislocation of the talonavicular joint (Figure B), and treatment involves serial manipulation and casting followed by surgical release and talonavicular reduction and pinning at 6-12 months of age.

CVT represents a rare congenital anomaly that is most typically associated with neuromuscular or chromosomal abnormalities in neonates, with >50% associated with the presence of cerebral palsy, congenital hip dislocations, arthrogryposis, myelomeningocele, etc. The incidence is, overall, rare (occurring in only 1:150,000 live births) but is present bilaterally in over 50% of involved cases. The typical deformity presents as that of a rigid, rocker-bottom foot (Figure A) with fixed hindfoot equinovalgus, rigid midfoot dorsiflexion, and forefoot abduction. These deformities cause soft tissue contractures with displacement of the peroneus longus and posterior tibialis tendons so that they act as dorsiflexors instead of plantar-flexors, exacerbating the dorsiflexion deformity and rocker-bottom phenomenon. Treatment first begins with serial manipulation to stretch the dorsolateral soft tissues, followed by closed versus open reduction and pinning of the talonavicular joint at 6-12 months with or without Achilles tenotomy. Depending on the additional soft tissue contractures present, concomitant lengthening of the peroneals/toe extensors can be performed, in addition to plantar calcaneonavicular (Spring) ligament reconstruction, however, these procedures are never performed in isolation and always accompany proper reduction and stabilization of the talonavicular joint itself.

Miller et al. reviewed the etiology and management of congenital vertical talus (CVT). The authors note that CVT is a rare foot deformity that, if left untreated, causes significant disability, including pain and functional limitations. Despite a likely heterogeneous etiology, recent evidence suggests a strong genetic component linked to early limb development. They conclude that management typically involves a minimally invasive approach that relies on serial manipulation and casting to achieve most of the correction, which has been shown to produce excellent short-term results with regard to clinical and radiographic correction in both isolated and non-isolated cases of vertical talus, followed by K-wire fixation of the talonavicular joint to maintain the reduction.

Chan et al. reviewed the Dobbs method for the correction of idiopathic and teratological congenital vertical talus. The authors note that, traditionally, CVT correction involved extensive soft tissue releases that were associated with high complication rates. The Dobbs method is less invasive and comprises serial manipulation and casting, followed by minimally invasive reduction and K-wire fixation of the talonavicular joint and percutaneous Achilles tenotomy. They retrospectively reviewed 10 children with 18 affected feet, with 5 of the children having teratological CVT, and concluded that the Dobbs method is a less invasive and effective technique of CVT correction for both teratological and idiopathic patients despite a higher (but not statistically significant) recurrence rate being observed in the teratological group.

Figure A represents a clinical photo of a patient with bilateral rigid, rocker-bottom foot deformities characteristic of CVT. Figure B is a plantarflexion lateral radiograph showing persistent dorsal dislocation of the talonavicular joint in a patient with CVT.

Incorrect Answers:
Answer 1: A gastrocnemius recession in isolation would not be indicated as an appropriate treatment for a patient with CVT.
Answer 2: Observation and reassurance alone are not adequate treatment options if talonavicular joint reduction has not been performed.
Answers 3 and 4: Though these procedures are often performed alongside reduction and pinning of the talonavicular joint, they are not indicated in isolation if the joint has not been reduced.