Congenital Vertical Talus

Original Editor - Veena Jose Panicker Top Contributors - Stacy Lawrence, Veena Jose Panicker, Vidya Acharya, Kim Jackson, Alexandra Stead and Ewa Jaraczewska

Introduction

Congenital Vertical Talus (CVT) is a rare, rigid foot deformity present at birth, characterised by fixed dorsal dislocation of the navicular bone on the talar head, resulting in a characteristic "rocker-bottom" appearance of the foot. The deformity involves hindfoot equinus and valgus, midfoot dorsiflexion and forefoot abduction, creating significant functional challenges if left untreated. First described by Rocher in 1913 as "pied en piolet," CVT represents one of the most severe congenital foot deformities requiring prompt recognition and intervention to prevent long-term disability. The condition has also been known as reversed clubfoot, congenital valgus flatfoot, pied plat valgus congenital, congenital convex pes valgus and rocker-bottom foot. It is important to note that over the past 10 years there has been no high quality research papers on the subject matter.

Classification

Clinicians classify CVT into two primary categories based on aetiology:

A) Isolated vs Non-isolated

Idiopathic CVT (Isolated)

• Approximately 30-50% of cases
• No associated systemic conditions
• May have a genetic component (HOXD10 gene mutations)
• Often familial inheritance patterns

Teratological CVT (Syndromic / Non-isolated)

• Approximately 50-62% of cases
• Associated with underlying conditions, including:
  • Neural tube defects: Spina bifida, myelomeningocele
  • Neuromuscular disorder: Arthrogryposis, cerebral palsy
  • Chromosomal abnormalities: Trisomy 13, 15, 18
  • Genetic syndromes: Costello syndrome, Larsen syndrome

B) Hamanishi Classification

Hamanishi developed a five-group classification system based on associated conditions. Using radiological measurements to assess the severity of a dislocation:

1. Neural tube defects or spinal anomalies
2. Neuromuscular disorders
3. Malformation syndromes
4. Chromosomal aberrations
5. Idiopathic CVT

Epidemiology

Congenital vertical talus occurs in approximately 1 in 10,000 live births. Earlier research articles suggested an estimated 1 in 150,000 was determined to be a significant underestimation, possibly due to misdiagnosis or delayed recognition of the condition in newborns. CVT demonstrates no sex preference.

Aetiology and Pathophysiology

While the exact aetiology of CVT remains incompletely understood, researchers have identified multiple contributing factors.

Genetic Factors

Recent research revealed a genetic mutation associated with idiopathic CVT. These mutations include:

1. HOXD10 gene mutations identified in families with isolated CVT and Charcot-Marie-Tooth-like foot deformities.
2. CDMP-1 gene mutations are associated with variable hand and foot abnormalities, including CVT.
3. Autosomal dominant inheritance patterns are documented in some families.

Skeletal Muscle Abnormalities

Muscle biopsies from patients with CVT show abnormalities in approximately 45-64% of cases, including irregular fibre sizes, small Type 1 fibres, and abnormal fibre distribution. However, it is uncertain whether these muscle changes cause the deformity or result from it. The presence of muscle abnormalities may explain why some CVT cases are more rigid and resistant to treatment; however, the causal relationship needs further investigation.

Intrauterine Factors

Limited intrauterine space and abnormal foetal positioning may contribute to CVT development in some cases, particularly those associated with other positional deformities such as developmental dysplasia of the hip and metatarsus adductus.

Clinical Presentation

The clinical diagnosis of CVT relies on characteristic physical findings present at birth. Clinical examination reveals characteristic deformities across three anatomical regions of the foot:

• Hindfoot deformities: fixed equinus (plantar flexion) position. Valgus (outward turning) alignment. Inability to achieve neutral dorsiflexion
• Midfoot deformities: fixed dorsiflexion at the midtarsal joint. Dorsal dislocation of the navicular on the talar head. Prominent talar head palpable on the plantar-medial foot.
• Forefoot deformities: abduction (outward deviation). Dorsiflexion relative to the hindfoot.

Characteristic Appearance:

• Rocker-bottom foot
• Convex plantar surface
• Rigid deformity (distinguished from flexible flatfoot)
• Possible callosities (thickened, hardened skin) over the talar head in walking-age children.

A comprehensive motor function assessment is essential. This would include great toe flexion and extension, lesser toe movement and strength of ankle dorsiflexion as well as plantar flexion.

Diagnosis

As mentioned previously, CVT is typically diagnosed at birth through physical examination, although it may be misdiagnosed initially as other common foot deformities, such as:

• Calcaneovalgus foot
• Oblique talus
• Clubfoot
• Flexible flatfoot

Radiographic Evaluation

This would require three essential X-ray views:

• AP View (weight bearing): shows increased talocalcaneal angle and forefoot abduction with uncovered talar head
• Lateral view (neutral): reveals vertical talus orientation and dorsally dislocated navicular bone
• Lateral view (forced plantar flexion) - Most critical: talar axis-metatarsal angle stays >30 degrees in CVT and does not correct. This definitive diagnostic test distinguishes CVT from flexible oblique talus. In an oblique talus, this angle corrects to <30 degrees.

Vertical talus is typically diagnosed through a physical examination at birth, where the deformity is visibly noticeable. Imaging techniques such as X-rays are often used to confirm the diagnosis and evaluate the severity of the deformity, which reveals a dorsally dislocated talonavicular joint.

Clinical Red Flags

Healthcare professionals should observe and recognise red flags for potential complications and associated conditions:

Immediate referral is warranted with the following:

• Signs of compartment syndrome after cast removal. Observe for the 5 P's - pain, pallor, pulselessness, paraesthesia, paralysis.
• Suspected non-accidental injury
• Rapidly progressive deformity despite treatment
• Signs of systemic infection

Urgent referral is warranted with the following:

• Failure to achieve correction after 6-8 casts
• Wound dehiscence or infection post-surgery
• Cast-related skin breakdown or pressure sores
• New neurological symptoms (weakness, sensory changes)
• Suspected underlying neuromuscular diagnosis

Differential Diagnosis

CVT must be differentiated from:

Condition	Key Distinguishing Features
Calcaneovalgus Foot	Flexible, hindfoot in dorsiflexion (not equinus), resolves spontaneously
Oblique Talus	Flexible, corrects to <30 degrees on plantar flexion lateral X-ray
Flexible Flatfoot	Flexible, arch reconstitutes with toe-standing, develops later in childhood
Clubfoot	Rigid cavus and adduction, hindfoot varus (not valgus)
Posteromedial Tibial Bow	Associated tibial bowing, calcaneovalgus foot position

Management

Successful CVT management requires a comprehensive treatment approach with clearly defined objectives. The primary goals of CVT treatment are to:

1. Restore anatomical alignment of talus, navicular and calcaneus
2. Achieve a plantigrade (ability to place the entire sole on the ground during standing), functional foot
3. Maintain ankle and subtalar joint mobility
4. Prevent long-term pain and disability
5. Enable normal shoe wear and ambulation

Surgical Treatment

Traditionally, (before 2006) CVT was treated with extensive open surgery involving large incisions with complete soft tissue releases and multiple tendon lengthening and joint capsule cuts. This would lead to major complications such as severe joint stiffness, talus bone death, wound infection, poor correction rates, need for frequent surgical revision, and early arthritis. The current gold standard is the Dobbs Method, a minimally invasive "reverse Ponseti" technique combining serial manipulation and casting (average 5-7 casts) followed by percutaneous surgery (Achilles tenotomy and talonavicular joint pinning). This approach yields superior outcomes with significantly fewer complications compared to extensive open surgical release, with 100% initial correction rates and 80% recurrence-free outcomes at mid-term follow-up.

Non-operative Treatment

Serial Casting Protocol (The Dobbs Method)

The Dobbs method also termed the "reverse Ponseti technique," uses the talar head as a fulcrum to gradually reduce the navicular dislocation through serial manipulation and casting:

• Manipulation: Gentle sustained pressure applied to dorsal navicular whilst bringing foot into plantar flexion and adduction.
• Long leg casting: Applied weekly with knee flexed 90 degrees to prevent slippage
• Number of casts: Average 5-7 casts (range 4-10), typically requiring fewer casts for idiopathic CVT compared to syndromic cases
• Success is achieved when talar axis- first metatarsal base angle corrects to <30 degrees on forced plantar flexion lateral radiograph

Following serial casting, it is possible to have minimally invasive surgery consisting of percutaneous Achilles tenotomy and talonavicular joint pinning with K-wire stabilisation for 6 weeks. This concept uses the talar head as a pivot point to gradually reduce the dislocation in the opposite direction of the clubfoot correction.

International Classification of Functioning, Disability and Health (ICF)

Application of the ICF framework to CVT management
Body Structure & Functions (Impairments)	Activities (Activity Limitations)	Participation (Participation Restrictions)	Environmental Factors (Barriers/Facilitators)	Personal Factors
- b770: Gait pattern functions (altered due to foot deformity) - b7150: Stability of joints (reduced in ankle and subtalar joints) - s7502: Structure of ankle joint (dorsally dislocated talonavicular joint)	- d4500: Walking short distances (may be impaired without treatment) - d5400: Putting on footwear (difficulty due to foot shape) - d9200: Play (may be limited in untreated cases)	- d7504: Community life (potential social limitations) - d9201: Sports (may require modifications)	- e1101: Drugs (orthotic devices as facilitators) - e355: Health professionals (physiotherapist, surgeon as facilitators) - e580: Health services (access to specialised care)	- Parental compliance with bracing and stretching protocols - Family support structures - Socioeconomic factors affecting access to care

Physical Therapy Management

Physiotherapy plays an essential role in successful CVT management and prevention of recurrence. The physical therapist's role encompasses education, exercise prescription, orthotic management and long-term monitoring.

Bracing Protocols - CVT Specific

Ensure foot is positioned straight ahead (0 degrees rotation, not externally rotated).Wearing schedule:

• 1-4 months: 23 hours/day (critical period)
• 4-24 months: 12-14 hours nightly
• Age 2-4: gradual weaning (may require extending to age 5 for syndromic cases)

Compliance with bracing protocols is the single most important factor in preventing recurrence. Non-compliance accounts for the majority of treatment failures and recurrent deformities.

Physiotherapy Interventions by Phase

The below table shows the stages of CVT management.

Phase 1:	Post-Casting / Post-Surgical (Weeks 0-6)	- Wound care education - Gently passive range of motion exercises - Positioning education for parents - Early mobilisation strategies
Phase 2:	Active Rehabilitation(Post-op Rehab) (Weeks 6-12)	- Stretching exercises: 6-8 times daily during diaper changes Ankle plantar flexion Foot adduction Gentle inversion exercises - Progressive weight-bearing as tolerated - Gait training when the child begins to walk. - Gentle stretches prevent recurrence; avoid pain by not using force.
Phase 3:	Long-Term Maintenance (12 months - skeletal maturity)	- Strengthening exercises: Intrinsic foot muscle strengthening Ankle and hindfoot strengthening Balance training on various surfaces. - Functional mobility training - Orthotic management and monitoring - Activity modification guidance
Long-Term ManagementPhysical therapists typically initiate long-term management at 10-14 months with proper foot positioning and weight-bearing, strengthening and balance training ( on various surfaces). Follow-up schedule: 0-2 yrs: every 3 months 2-7 yrs: every 6-12 months 7+ yrs: every 1-2 years until skeletal maturity

Red flags for recurrence include:

• Rocker-bottom appearance returns
• Shoe-fitting difficulty
• Limping or gait changes
• Reduced ankle motion

Interdisciplinary Management Approach

Collaborative efforts between multiple healthcare professionals is required for optimal CVT management:

Core Team:

• Paediatric Orthopaedic Surgeon - role is to diagnose, decide on surgical intervention and additional procedures for curative care.
• Orthotist - focus on custom brace fabrication, fitting and adjustments.
• Paediatric Nurse - focus on wound care, family support an care coordination
• Radiographer - focus diagnostic imaging and monitoring treatment.

Extended Team:

• Geneticist - evaluates for underlying genetic syndromes and offer family counselling
• Neurologist - assess and manage associated neuromuscular conditions
• Developmental Paediatrician - monitors the overall development
• Social Worker - offers family support and resource coordination

Regular multidisciplinary team meetings aide with optimising care planning and overall outcomes for children with CVT.

Prognosis

With proper treatment, research evidence demonstrates:

Idiopathic CVT (Isolated):

Idiopathic CVT is with proper management is noted to have:

• 80-90% excellent outcomes of normal and functional feet
• Full range of motion maintained
• Sports participation, normal shoes, pain-free walking
• Correction proven to last at 10 years follow-up

Syndromic CVT (Associated Conditions):

Syndromic CVT is with proper management is noted to have:

• 70-80% good outcomes with functional feet
• Higher recurrence rate in syndromic CVT (23%) compared to idiopathic CVT (17%)
• May need repeated procedures
• Overall mobility is limited more by the underlying condition than foot deformity

Predictor of Success

Success with managing CVT is based on a few factors:

Favourable Prognosis Factors	Unfavourable Prognosis Factors
Isolated CVT with no other condition	Associated neuromuscular/genetic conditions
Early treatment (before 6 months old)	Late diagnosis (after walking age)
Excellent parent compliance with bracing/stretching	Poor bracing compliance
Strong toe motor function	Weak/absent toe motor function
Idiopathic CVT	Syndromic/teratological CVT
Dobbs' method of treatment	Treatment with extensive open surgery

Without treatment, individuals with untreated CVT are likely to:

• Develop progressive rigid flatfoot leading to lifelong disability
• Painful calluses leading to the inability to wear normal shoes
• Abnormal gait = chronic pain
• Early arthritis
• Significant functional and social impairment

Summary

Congenital vertical talus is a rare but treatable foot deformity affecting approximately 1 in 10,000 live births. Early recognition and intervention using the Dobbs method (serial casting followed by minimally invasive surgery) have revolutionised outcomes. Physiotherapy plays a critical role throughout the treatment continuum, from postural education and bracing compliance to long-term monitoring. With the appropriate treatment and adherence to rehabilitation protocols, most children with CVT can achieve pain-free, functional feet that allow normal shoe wear and participation in physical activities. Early diagnosis, family education and multidisciplinary collaboration are key to optimal outcomes.