Causes of High Arch Foot (Pes Cavus)
Pes cavus is predominantly caused by underlying neurological disorders, with two-thirds of patients having an identifiable neurologic diagnosis, making neurological evaluation essential for any patient presenting with this deformity. 1
Primary Etiologic Categories
Neurological Causes (Most Common)
Progressive neuromuscular conditions:
- Charcot-Marie-Tooth disease is the most frequent cause of pes cavovarus deformity, resulting from palsy of intrinsic foot muscles 2, 3
- Peripheral neuropathies and motor sensory conditions 3
- Spinal dysraphism and spinal cord pathology 3, 1
Nonprogressive neurological conditions:
Structural and Developmental Causes
Congenital and developmental:
- Residual clubfoot deformity 4
- Idiopathic pes cavus (variant of normal foot morphology in some healthy individuals) 2, 4
Associated conditions with genetic syndromes:
Secondary Causes
Traumatic:
- Post-traumatic muscle imbalance 4
Neuropathic complications:
- Peripheral motor neuropathy leading to abnormal foot biomechanics with clawing of toes, high arch, and subluxed metatarsophalangeal joints 5
Pathomechanics
The deformity develops through muscle imbalance that initially creates a flexible deformity, which progresses to fixed bony deformity if untreated 3, 4. In pes cavovarus specifically, the deformity involves three-dimensional rotation of the calcaneopedal unit with first ray plantarflexion and fixed heel varus when rigid 2, 3.
Clinical Significance
Pes cavus creates significant functional problems:
- Abnormal plantar pressure distribution leading to pain along metatarsal heads and lateral foot border 1
- Increased risk of ankle instability and frequent sprains 1
- In diabetic or neuropathic patients, the elevated arch and pressure points significantly increase ulceration risk 5, 6
Diagnostic Approach
Essential evaluation components:
- Thorough neurological examination to identify underlying motor, sensory, or spinal cord pathology 3, 1
- Assessment for cutaneous stigmata suggesting spinal dysraphism 5
- Cavovarus block test to assess hindfoot flexibility, which directs treatment decisions 3
- Standing lateral radiographs to confirm diagnosis and measure arch elevation 1
- MRI of brain and spine when neurological etiology suspected 5, 3
- Electrodiagnostic studies for suspected peripheral neuropathy 3
Critical pitfall: Failing to identify the underlying neurological cause can result in progressive deformity and missed opportunities for treating the primary condition 1.