Vertical Talus

Vertical talus (also called congenital vertical talus or rocker-bottom foot) is a rare congenital foot deformity in which the talus bone is locked in a vertical position, causing the midfoot joints to dislocate. The result is a rigid, convex-soled foot that resembles the bottom of a rocking chair — hence the term "rocker-bottom foot."

Unlike flexible flat feet, vertical talus is a rigid deformity present from birth and will not resolve on its own. It requires early, structured treatment to achieve a functional, pain-free foot.

Vertical talus can be isolated or associated with underlying conditions:

• Idiopathic (isolated): Approximately half of cases have no identifiable cause and occur in otherwise healthy infants
• Neuromuscular conditions: Spina bifida, arthrogryposis, and sacral agenesis are commonly associated
• Chromosomal syndromes: Trisomy 13, 15, and 18 — genetic workup is recommended in all cases
• Intrauterine positioning: Abnormal fetal position during development can contribute
• Both feet are affected in approximately 50% of cases

• Characteristic "rocker-bottom" appearance of the foot — convex sole, prominent heel
• The foot is rigid — unlike flexible flat feet, the arch cannot be recreated by passive manipulation
• The forefoot is dorsiflexed (pointing upward) and the hindfoot is in equinus (pointing downward)
• Tightness of the Achilles tendon and anterior tendons
• If untreated and the child begins walking, painful calluses develop on the prominent midfoot where weight is borne abnormally
• Associated neurological or systemic features may be present depending on underlying cause

• Clinical examination confirming rigidity and rocker-bottom deformity
• Lateral X-rays of the foot in forced plantar flexion — the talus remains vertical (axis greater than 45°), confirming the diagnosis
• Ultrasound can be helpful in very young infants before bones are ossified
• Genetic testing (chromosomal karyotype) to identify associated syndromes
• Neurological assessment and spine imaging (MRI) to evaluate for spinal dysraphism
• Echocardiogram and renal ultrasound as part of syndrome workup when indicated

Treatment should begin as early as possible — ideally in the first weeks of life:

• Reverse Ponseti serial casting: The foot is progressively stretched and cast in the opposite direction to club foot — casting begins from birth and continues for 4–6 weeks to stretch soft tissues and partially reduce the talonavicular joint
• Mini-open surgical reduction: After casting, a small surgical procedure is performed to fully reduce and stabilise the talonavicular joint. A temporary Kirschner wire (K-wire) holds the joint in position while healing occurs
• Achilles tenotomy: The Achilles tendon is lengthened percutaneously at the time of surgery to correct hindfoot equinus
• Post-operative casting and bracing: A full-length cast is worn for 6–8 weeks after surgery, followed by foot abduction bracing (similar to club foot protocol) to maintain correction
• Salvage procedures: For older children or failed primary treatment — more extensive surgery may be required to achieve a plantigrade foot