Congenital Vertical Talus

Courtesy: Mathew Dobbs, Ashok Shyam, IORG, OrthoTV

 

Definition

• Congenital Vertical Talus (CVT) is a rare rigid foot deformity

• Characterized by:

  • Fixed dorsal dislocation of the talonavicular joint

  • Rigid hindfoot equinus

• Produces the classic “rocker-bottom foot” deformity

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Associated Conditions

Central Nervous System / Spinal Cord

• Myelomeningocele

• Spinal muscular atrophy

• Diastematomyelia

• Sacral agenesis

Musculoskeletal Disorders

• Distal arthrogryposis

• Arthrogryposis multiplex congenita

• Neurofibromatosis

Chromosomal Abnormalities

• Trisomy 18

• Trisomy 15

• Trisomy 13

Known Genetic Syndromes

• Prune belly syndrome

• Rasmussen syndrome

• Split hand–split foot syndrome

• Costello syndrome

• De Barsy syndrome

Single Gene Defects

• HOXD10

• CDMP1

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Etiology (Proposed Mechanisms)

• Abnormal skeletal muscle development

  • Type I muscle fiber size

• Congenital vascular abnormalities

  • Deficient posterior tibial artery

  • Dominance of anterior tibial and dorsalis pedis arteries

• Muscle imbalance

• Intrauterine compression ± arthrogryposis

• Arrest of fetal foot development between 7th–12th weeks of gestation

• Autosomal dominant inheritance

  • Parent-to-child transmission reported

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Clinical Presentation

Foot Deformity

• Rocker-bottom foot

• Fixed hindfoot equinus

• Rigid midfoot dorsiflexion

• Forefoot abducted and dorsiflexed

• Elevation of lateral toes

• Prominent talar head

• Callosities over talar head

• Tight peroneal tendons

• Deep dorsolateral skin crease anteroinferior to lateral malleolus

Gait Abnormality

• Peg-leg gait

  • Excessive heel contact

  • Limited forefoot contact

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Classification

Coleman Classification

• Type I: CVT with isolated talonavicular dislocation

• Type II: CVT with talonavicular and calcaneocuboid dislocation

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Lichtblau Classification

• Group 1 (Teratogenic)

  • Rigid, bilateral

  • Present at birth

  • Tight extensors and heel cords

• Group 2 (Neurogenic)

  • Milder deformity

  • Associated with myelomeningocele or neurofibromatosis

• Group 3 (Acquired)

  • Due to intrauterine malposition

  • Moderate severity

  • Partially correctable

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Pathologic Anatomy

Skeletal Abnormalities

• Talus

  • Flattened head and neck

  • Elongated and ovoid

  • Deviated medially and plantarward

• Calcaneus

  • Displaced posterolaterally relative to talus

  • Tilted into equinus

  • Contacts distal fibula

• Navicular

  • Dorsally and laterally displaced

  • Hypoplastic

• Cuboid

  • Deformed and laterally deviated

• Dorsolateral subluxation or dislocation of the calcaneocuboid joint

• Elongated medial column

• Shortened lateral column

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Ligamentous and Tendinous Abnormalities

• Attenuated spring ligament

• Contracted tibionavicular part of superficial deltoid ligament

• Contracted:

  • Calcaneofibular ligament

  • Interosseous talocalcaneal ligament

• Muscle–tendon contractures:

  • Tibialis anterior

  • Long toe extensors

  • Peroneus brevis

  • Triceps surae

• Posterior tibial and peroneal tendons displaced anteriorly

  • Act as dorsiflexors instead of plantar flexors

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Vascular Abnormalities

• Dominant blood supply from:

  • Anterior tibial artery

  • Dorsalis pedis artery

• Posterior tibial artery is deficient

• Clinical implication:

  • Extensive anterior dissection + forced plantarflexion can compromise vascular supply

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Imaging Evaluation

Plain Radiographs

Lateral View of Foot

• Talus oriented vertically

• Talus parallel to long axis of tibia

• Calcaneus in equinus

• Increased talocalcaneal angle

• Navicular displaced dorsally and laterally

• Navicular aligned with long axis of first metatarsal

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Forced Dorsiflexion Lateral View

• Talus and calcaneus remain plantarflexed

• Confirms fixed equinus

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Forced Plantarflexion Lateral View

• Navicular fails to reduce onto talus – Congenital Vertical Talus

• If navicular reduces – Congenital Oblique Talus

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Key Angles

• Meary’s angle > 20°

• Talocalcaneal (Kite) angle > 40°

  • Normal: 20–40°

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Ultrasound (USG)

• Useful in infants before ossification

• Helps assess talonavicular alignment dynamically

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Management (Brief Overview)

• Early diagnosis and treatment are critical

• Resistant or neglected cases may require:

  • Extra-articular procedures

  • Bone grafting (e.g., anterior tibial graft)

  • Triple arthrodesis in older children

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Complications

Postoperative

• Residual midfoot sag

• Persistent forefoot abduction

• Decreased foot and ankle motion

• Recurrent deformity

• Ankle and subtalar joint stiffness

Severe / Late Complications

• Ischemic necrosis , may require amputation

• Neglected deformity in older children – Triple arthrodesis

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Key Take-Home Points

• CVT is a rigid, non-reducible deformity

• Always differentiate from congenital oblique talus

• Strong association with neuromuscular and genetic conditions

• Imaging with stress views is diagnostic

• Early treatment improves outcomes and reduces need for fusion surgery