Cavus Feet (Pes Cavus)

Key Points

Characterized by abnormally high medial longitudinal arch
Often associated with underlying neurological conditions
Can be flexible or rigid
Usually progressive without treatment
80% cases have neurological etiology

Etiology

Neurological Causes (80%)

Charcot-Marie-Tooth Disease (Most Common)
- Progressive peripheral neuropathy
- Presents in first decade
- Autosomal dominant inheritance
Other Neurological Conditions:
- Spinal cord tumors
- Spina bifida
- Poliomyelitis
- Friedrich's ataxia
- Cerebral palsy
- Syringomyelia

Non-neurological Causes (20%)

Idiopathic (Most common non-neurological)
Post-traumatic
Residual clubfoot
Burns/contractures
Compartment syndrome sequelae

Pathoanatomy

Primary Deformities:
- Elevated medial longitudinal arch
- Plantar fascia contracture
- First ray plantarflexion
- Hindfoot varus
Muscle Imbalance:
- Strong ankle plantar flexors
- Weak ankle dorsiflexors
- Intrinsic muscle wasting

Clinical Features

History Taking

Key Questions:
- Age of onset
- Family history
- Progression rate
- Associated symptoms
- Neurological symptoms
- Impact on activities
Common Complaints:
- Lateral foot pain
- Frequent ankle sprains
- Shoe wear problems
- Metatarsalgia
- Callus formation
- Gait instability

Physical Examination

Foot Examination:
- Coleman block test
- Arch height assessment
- First ray position/flexibility
- Hindfoot alignment
- Forefoot positioning
Neurological Assessment:
- Muscle strength testing
- Sensory examination
- Deep tendon reflexes
- Muscle bulk/wasting
Gait Analysis:
- Walking pattern
- Foot progression angle
- Balance assessment
- Lateral heel wear

Diagnosis & Assessment

Imaging Studies

Weight-bearing Radiographs:
- AP, lateral, hindfoot alignment views
- Key measurements:
  - Meary's angle (> 5°)
  - Calcaneal pitch (> 30°)
  - Hibbs angle
  - First metatarsal angle
Advanced Imaging:
- CT scan:
  - 3D deformity assessment
  - Surgical planning
- MRI:
  - Soft tissue evaluation
  - Neural structures

Neurological Workup

Essential Tests:
- EMG/NCV studies
- Genetic testing (CMT)
- Spinal MRI if indicated
- Neurologist consultation

Management Approach

Conservative Treatment

Orthotic Management:
- Custom orthoses with:
  - Lateral posting
  - Metatarsal support
  - Arch support
- AFO for neurological cases
Physical Therapy:
- Stretching exercises
- Balance training
- Muscle strengthening
- Gait training
Footwear Modifications:
- High-topped shoes
- Rocker bottom soles
- Lateral sole wedges

Surgical Management

Indications:
- Failed conservative treatment
- Progressive deformity
- Chronic pain
- Functional limitation
Surgical Options:
- Soft Tissue Procedures:
  - Plantar fascia release
  - Tendon transfers
  - Achilles lengthening
- Bony Procedures:
  - First metatarsal osteotomy
  - Calcaneal osteotomy
  - Midfoot osteotomy
- Complex Reconstruction:
  - Triple arthrodesis
  - Midfoot fusion
  - External fixation

Postoperative Care

Phase 1 (0-6 weeks):
- Non-weight bearing
- Cast immobilization
- Wound care
Phase 2 (6-12 weeks):
- Progressive weight bearing
- ROM exercises
- Orthotic fitting
Phase 3 (3-6 months):
- Strengthening
- Gait training
- Return to activities

Further Reading