Congenital Vertical Talus [CVT]
Congenital vertical talus is the ankle and foot disorder.
It is characterized by fixed dorsal dislocation of the talonavicular joint in conjunction with rigid hindfoot equinus.
Synonyms of congenital vertical talus are rocker-bottom foot and talipes convex pes valgus.
The exact cause is unknown in most cases.
The proposed theories are skeletal muscle abnormalities, vascular abnormalities, and muscle imbalance.
CVT is often associated with arthrogryposis, myelomeningocele, Prune-belly syndrome, spinal muscular atrophy, Rasmussen syndrome, Trisomy 13-15, and 18.
Usually presents with deformity since birth.
On examination, the foot will be convex on the plantar surface at the apex of the talar head.
Calcaneus will be fixed in the equinus with tight tendo Achilles.
Navicle will be palpable on the dorsolateral aspect.
The peroneal and tibialis anterior tendon will be taut, so the foot will be everted, valgus and externally rotated position.
Plain radiographs are necessary to make the diagnosis.
Weight-bearing anteroposterior, lateral, plantar flexion and dorsiflexion lateral view are needed to differentiate between vertical and oblique talus.
In infancy, gentle manipulation with immobilization in the cast is beneficial as it stretches the soft tissues. However reduction of the talonavicular joint is rarely possible just by the conservative method.
1-4 years – Open reduction, realignment of the talonavicular, and subtalar joint.
3/>3 years – With severe deformity, may need navicular excision.
4-8 years – Open reduction, soft tissue procedures, and extra-articular subtalar arthrodesis.
>12 year – Triple arthrodesis
Untreated cases will results in disability with the rigid plantarflexed head of the talus, produce pressure-induced callosities and pain.
There will gait disturbance with no push-off phase.