Paediatric Flatfeet and Claw toes

Courtesy: Dr Baljinder Dhinsa, Foot and Ankle Surgeon, London, UK

Pes Planus / Planovalgus

Definition

• Traditionally described as loss of the medial longitudinal arch.
• More complex deformity involving:
  • Hindfoot valgus
  • Subtalar joint subluxation
  • Forefoot abduction
  • Forefoot supination
  • Possible Achilles tendon tightness

Flexible Flatfoot

Epidemiology

• Infants are normally born with flat feet.
• Development of the medial arch occurs between 7–10 years.

Prevalence:

• Up to 50% of children at age 3 may have flat feet.
• Around 24% at age 6.
• 15–20% of adults may have flexible flat feet.

Most cases are asymptomatic.

Symptoms may correlate with:

• Body Mass Index (BMI)
• Lateral displacement of the navicular

Clinical Assessment

History

Important points:

• Birth history
• Perinatal complications
• Developmental milestones
• Family history of:
  • Flatfoot
  • Lower limb deformities
• Activity limitation
• Effect on sports participation
• Pain during walking or running

Examination

Follow standard orthopaedic principles:

Look

• Foot alignment
• Medial arch
• Hindfoot valgus

Feel

• Tenderness
• Achilles tightness

Move

Assess flexibility of deformity.

Tests for Flexible Flatfoot

• Non-weight bearing: arch reconstitution occurs.
• Tiptoe test: medial arch reforms.

Failure of arch reconstitution suggests rigid deformity.

Radiographic Evaluation

Standard Imaging

Weight-bearing radiographs:

• AP (dorsoplantar)
• Lateral
• Oblique views

Lateral View

Assess:

• Talar plantarflexion
• Meary’s angle
• Presence of midfoot break

AP View

Evaluate:

• Talocalcaneal angle
• Talonavicular coverage

Oblique View

Useful for identifying:

• Calcaneonavicular coalition

Advanced Imaging

• CT scan
  • Best for coalition evaluation
• MRI
  • Identifies fibrous or cartilaginous coalition

Non-Operative Management of Flexible Flatfoot

First-line treatment.

Options include:

Orthotics

• Medial arch support
• Heel posting to correct valgus
• Reduce strain on posterior tibial tendon

Important considerations:

• No role in children under 3 years.
• Gradual adaptation required.

Physiotherapy

• General stretching
• Ankle mobility exercises

Evidence for intrinsic muscle strengthening is limited.

Surgical Management of Flexible Flatfoot

Indications:

• Persistent pain
• Activity limitation
• Failure of conservative treatment

Principle:

• Joint-preserving surgery

Calcaneal Osteotomy (Lateral Column Lengthening)

Common surgical option.

Mechanism of Correction

Transverse plane

• Elevation of the sinus tarsi floor

Coronal plane

• Medial shift of posterior calcaneal fragment

Sagittal plane

• Correction of forefoot abduction

Technique

• Osteotomy performed near calcaneocuboid joint
• Tricortical bone graft often used
• Fixation may not always be necessary in children

Subtalar Arthroereisis

• Screw inserted into sinus tarsi
• Limits excessive subtalar pronation.

Advantages:

• Minimally invasive

Disadvantages:

• Possible sinus tarsi pain
• Risk of overcorrection

Long-term results remain uncertain.

Rigid Flatfoot

Important causes include:

• Tarsal coalition
• Congenital vertical talus
• Accessory navicular syndrome

Rigid deformities require careful evaluation.

Tarsal Coalition

Pathophysiology

• Failure of segmentation of primitive mesenchyme.
• Leads to abnormal connection between tarsal bones.

Common types:

• Calcaneonavicular coalition
• Talocalcaneal coalition

Calcaneonavicular Coalition

Characteristics

• Present at birth but symptoms occur after ossification (8–14 years).
• Initially flexible due to cartilage.

Symptoms

• Foot pain
• Recurrent ankle sprains
• Difficulty walking on uneven surfaces

Radiographic Sign

• Anteater sign

Talocalcaneal Coalition

Characteristics

• Symptoms usually appear around 12 years of age.

Features

• Loss of subtalar motion
• Hindfoot stiffness
• Possible peroneal muscle spasm

Management of Tarsal Coalition

Non-operative Treatment

• Activity modification
• Immobilization (boot or cast)
• Orthotics

Surgical Treatment

Coalition Resection

Indications:

• <50% of joint surface involvement
• Minimal arthritis

Interposition materials:

• Fat
• Muscle
• Bone wax

Arthrodesis

Indications:

• Large coalition (>50%)
• Severe deformity
• Degenerative changes

Options:

• Subtalar fusion
• Triple arthrodesis

Congenital Vertical Talus

Definition

• Rare deformity also called rocker-bottom foot.

Features:

• Fixed dorsal dislocation of the navicular on talus
• Hindfoot equinus
• Forefoot dorsiflexion and abduction

Prevalence:

• Approximately 1 in 10,000 live births.

Associations

Seen with:

• Arthrogryposis
• Myelomeningocele
• Chromosomal abnormalities such as trisomy 13 and 18

Imaging

Key radiographs:

• Forced plantarflexion lateral view
• Forced dorsiflexion lateral view

Shows:

• Persistent talonavicular dislocation.

Treatment of Congenital Vertical Talus

Preferred method:
Dobbs technique

Steps

• Serial casting
• Gradual reduction of talonavicular joint
• Percutaneous Achilles tenotomy
• Temporary K-wire fixation of talonavicular joint

K-wire removal:

• After 4–5 weeks

Accessory Navicular

Definition

• Secondary ossification center of the navicular tuberosity.

Prevalence:

• 5–10% of population

Often asymptomatic.

Types

1. Separate ossicle
2. Synchondrosis type
3. Fused navicular

Clinical Features

• Medial foot pain
• Prominent navicular tuberosity
• Associated posterior tibial tendon dysfunction

Investigation

• X-ray
• MRI to differentiate:
  • Synchondrosis inflammation
  • Posterior tibial tendinopathy

Management

Non-operative

• Physiotherapy
• Orthotics
• Activity modification

Surgical Treatment

Kidner procedure

Steps:

• Excision of accessory navicular
• Advancement of posterior tibial tendon
• Reattachment to navicular using suture anchors

Post-operative care:

• Cast immobilization
• Boot for 4 weeks

Lesser Toe Deformities

Types include:

Mallet Toe

• Flexion deformity at DIP joint

Hammer Toe

• Flexion at PIP joint
• Hyperextension at MTP joint

Claw Toe

• Hyperextension at MTP
• Flexion at PIP and DIP joints

Etiology

Common causes:

• Tight footwear
• Trauma
• Post-surgical changes
• Neuromuscular disorders
• Plantar plate injury
• Metatarsal overload

Pathomechanics

• Instability at MTP joint leads to deformity.
• Hyperextension at MTP joint causes:
  • Extensor tendon dominance
  • Flexor tendon imbalance
• Leads to progressive deformity.

Management Principles

Key step:
Determine whether deformity is flexible or rigid.

Mallet Toe Treatment

Flexible

• Flexor digitorum longus tenotomy

Rigid

• DIP joint arthrodesis
• Fixation using K-wire

Hammer Toe Treatment

Flexible

• Flexor-to-extensor tendon transfer

With MTP hyperextension

• Dorsal capsular release
• Extensor tendon lengthening
• Weil osteotomy

Rigid

• PIP joint arthrodesis

Claw Toe Treatment

Flexible

• Tendon balancing procedures

Rigid

• PIP joint fusion
• Extensor tendon lengthening
• Metatarsal shortening osteotomy

Weil Osteotomy

Indication:

• Metatarsalgia
• MTP instability

Complications:

• Floating toe
• Scar tissue
• MTP stiffness

Minimally invasive techniques are increasingly used.