Cavus Foot (High Arched Foot - Pes Cavus)

Overview
Cavus foot, or pes cavus, is a structural deformity of the foot characterized by an abnormally high medial longitudinal arch.
The deformity can be mild and flexible or severe and rigid, and it alters weight distribution across the foot, increasing pressure on the heel and forefoot.
Cavus foot may be congenital, idiopathic, or associated with underlying neurologic disorders.
It can lead to pain, instability, calluses, recurrent ankle sprains, and progressive deformity if not managed appropriately.


Etiology (Causes and Risk Factors)
Cavus foot can result from neuromuscular disease, hereditary structural abnormalities, or post-traumatic and idiopathic causes. In many adults, an underlying neurologic disorder should be excluded.
Neurologic Causes (Most Common)

• Charcot–Marie–Tooth (CMT) disease – a hereditary motor and sensory neuropathy leading to muscle imbalance (weak peroneals, overactive posterior tibialis) and progressive cavovarus deformity.
• Friedreich’s ataxia and other hereditary spinocerebellar ataxias.
• Poliomyelitis (historically common, now rare).
• Spinal cord tumors or lesions, tethered cord, or cerebral palsy.

Other Causes

• Idiopathic or familial cavus with no identifiable neuromuscular cause.
• Post-traumatic: Malunited fractures or compartment syndrome causing muscle imbalance.
• Residual clubfoot deformity after childhood treatment.

Pathomechanics
Imbalances between agonist and antagonist muscle groups lead to:

• Forefoot-driven cavus (plantarflexion of the first ray).
• Hindfoot-driven cavus (fixed varus of the calcaneus).
• Often a combination, producing varus heel, adducted forefoot, and claw toes.

Clinical Presentation and Diagnosis
Symptoms

• Pain in the arch, forefoot, or lateral ankle.
• Recurrent ankle sprains due to hindfoot varus and lateral instability.
• Painful plantar calluses beneath metatarsal heads or heel.
• Claw toes or hammertoes.
• Shoe-fitting problems.

Physical Examination

• Inspection: High medial arch, varus heel, toe deformities, callus distribution.
• Coleman block test to distinguish forefoot- from hindfoot-driven deformity.
• Neurologic assessment: Strength, sensation, reflexes to detect underlying neuromuscular disease.
• Gait analysis for imbalance or instability.

Imaging

• Weight-bearing radiographs (AP, lateral, oblique) to evaluate arch height, calcaneal pitch, and Meary’s angle.
• MRI of spine or EMG/nerve conduction studies if a neurologic cause is suspected.

Treatment
Management depends on symptoms, severity, flexibility, and underlying etiology.
Nonoperative Management

• Custom orthoses or insoles: Lateral-wedged orthoses or cushioned insoles to redistribute plantar pressure and correct hindfoot varus.
• Ankle bracing: For recurrent sprains or instability.
• Physical therapy: Stretching of tight plantar fascia and Achilles tendon; strengthening of weak peroneals; balance training.
• Shoe modifications: Wide, cushioned shoes with rocker-bottom soles and extra-depth toe boxes.
• Callus care: Regular debridement and pressure offloading.

Nonoperative treatment is effective for mild, flexible deformities and for symptom control in less progressive cases.
Operative Management
Surgery is indicated when pain, instability, or progressive deformity persists despite conservative care.
Goals are to rebalance muscle forces, correct deformity, and preserve joint motion.
Common procedures include:

• Plantar fascia release to relieve tightness.
• First metatarsal dorsiflexion osteotomy for forefoot-driven cavus.
• Calcaneal osteotomy (Dwyer or lateralizing) to correct hindfoot varus.
• Tendon transfers (peroneus longus to brevis, posterior tibial to dorsum) to rebalance muscle forces.
• Midfoot or triple arthrodesis in severe rigid deformities or degenerative joints.

Postoperative rehabilitation typically includes a period of immobilization and gradual weight-bearing over 6–12 weeks, with full recovery taking several months.


Expectations and Prognosis

• Mild flexible cavus often remains stable with orthoses and footwear changes, allowing patients to maintain normal activity levels.
• Progressive or neurologic forms may worsen over time, particularly in hereditary neuropathies like Charcot–Marie–Tooth disease.
• Surgical outcomes are generally favorable, with significant pain relief, improved alignment, and reduced instability when procedures are appropriately matched to the deformity.
• Recurrence risk depends on the underlying cause; progressive neuromuscular disease may require long-term monitoring and additional procedures.

Key References (Peer-Reviewed)

1. Coleman SS, Chesnut WJ. A simple test for hindfoot flexibility in the cavovarus foot. Clin Orthop Relat Res. 1977;(123):60–62.
2. Mann RA, Hsu JD. Neurologic cavus foot. Etiology and management. Foot Ankle. 1982;3(1):1–8.
3. Ward CM, Dolan LA, Morcuende JA, Cooper RR. Long-term results of reconstruction for treatment of a flexible cavovarus foot in Charcot–Marie–Tooth disease. J Bone Joint Surg Am. 2008;90(12):2631–2642.
4. Younger AS, Hansen ST Jr. Adult cavovarus foot. J Am Acad Orthop Surg. 2005;13(5):302–315.
5. Burns J, Redmond AC, Ouvrier RA, Crosbie J. Development and validation of a clinical tool for assessing foot deformity in Charcot–Marie–Tooth disease. Neurology. 2005;65(10):1624–1627.
6. Sammarco VJ. Surgical correction of the cavus foot. Tech Foot Ankle Surg. 2011;10(1):1–12.

Summary
Cavus foot is a high-arched foot deformity often caused by neuromuscular imbalance but may also be idiopathic or post-traumatic.
Patients present with foot pain, calluses, instability, and frequent ankle sprains.
Diagnosis requires careful clinical and neurologic evaluation supported by imaging.
Treatment ranges from custom orthoses and bracing for flexible cases to osteotomy and tendon transfers for progressive or rigid deformities.
With appropriate management, most patients achieve durable pain relief, improved alignment, and restored function.