Courtesy: Amr Abdelgawad, Maimonaides Medical Centre, Brooklyn, NY, USA

Cavus Foot (High-Arched Foot)

Introduction

Cavus foot refers to an abnormally high medial longitudinal arch of the foot.

It is essentially the opposite of flatfoot deformity and is commonly associated with underlying neurological disorders.

In many patients, cavus foot may be the first or only sign of a neurological condition.

Etiology

Neurological Causes

Neurological disorders are the most common causes of cavus foot.

Important causes include:

Charcot-Marie-Tooth disease
Tethered cord syndrome
Diastematomyelia
Poliomyelitis
Spinal cord pathology

Important Clinical Principle

Cavus foot should always prompt careful neurological evaluation, especially in:

Progressive deformity
Unilateral deformity
Newly developing cavus foot

Pathophysiology

Muscle Imbalance

The deformity develops due to imbalance between muscle groups.

A classic imbalance is:

Peroneus longus overpowering tibialis anterior

Resulting Deformity

This imbalance produces:

Plantar flexion of the first ray
Hindfoot varus
Cavovarus deformity

Over time, the deformity may become rigid and progressive.

Cavovarus Foot

Most cavus feet are actually:

Cavovarus feet

meaning there is both:

High arch
Hindfoot varus

Tripod Theory of the Foot

Normal Foot Mechanics

Normally, body weight is distributed across three points:

Heel
First metatarsal head
Fifth metatarsal head

This is known as the tripod configuration.

Effect of Cavus Foot

In cavus deformity:

Weight distribution becomes abnormal
Forefoot overload occurs
Lateral border overload may develop

This contributes to instability and pain.

Clinical Features

Common Findings

Patients may present with:

High medial arch
Cavovarus alignment
Claw toes
Callosities
Lateral foot pain
Ankle instability

Neurological Assessment

A complete neurological examination is essential to assess for:

Muscle weakness
Sensory loss
Reflex abnormalities
Spinal pathology

Coleman Block Test

Purpose

The Coleman block test evaluates flexibility of the hindfoot varus deformity.

Technique

The patient stands with:

Heel and lateral border of foot supported
First metatarsal allowed to hang free

Interpretation

Varus Corrects

If hindfoot varus corrects:

Deformity is flexible
Forefoot-driven cavus deformity is likely

Varus Persists

If hindfoot varus remains:

Hindfoot deformity is rigid

This influences surgical planning.

Radiographic Evaluation

Meary’s Angle

Meary’s angle is formed between:

Long axis of talus
First metatarsal axis

Normal Value

Normal Meary’s angle is approximately:

0–5°

Abnormal Findings

An increased angle indicates:

Cavus deformity

Radiographs also help assess:

Hindfoot alignment
Forefoot plantar flexion
Degenerative changes

Management Principles

Step 1 – Identify the Underlying Cause

Because many cavus feet are neurological in origin:

Neurological evaluation is essential

This may include:

Neurology consultation
Spine imaging
Electrophysiological studies

Conservative Treatment

Bracing and Orthotics

Non-operative treatment may help in flexible deformities.

Common options include:

Lateral heel wedge
Custom orthotics
Bracing

Important Orthotic Principle

Support under the first metatarsal head is generally avoided because:

It may worsen the cavus deformity

Surgical Treatment

Progressive Nature

Most neurological cavus deformities are progressive and may eventually require surgery.

Surgical Goals

Surgery aims to:

Correct deformity
Balance muscle forces
Improve function
Prevent recurrence

Common Surgical Procedures

Plantar Fascia Release

Useful for:

Flexible cavus deformity
Soft tissue tightness

First Metatarsal or Cuneiform Osteotomy

Performed to correct:

Plantar-flexed first ray

Calcaneal Osteotomy

Indicated for:

Fixed hindfoot varus

Helps restore hindfoot alignment.

Tendon Transfers

Used to:

Rebalance muscle forces
Reduce progression
Improve function

Prognosis

Outcome depends on:

Severity of deformity
Flexibility
Underlying neurological condition
Timing of intervention

Progressive neurological disorders may continue to influence long-term results.

Key Clinical Pearls

Cavus foot is commonly neurological in origin.
Cavovarus is the most frequent deformity pattern.
Always perform a neurological examination.
Coleman block test determines hindfoot flexibility.
Meary’s angle helps quantify cavus deformity.
Early orthotic management may help flexible deformities.
Many progressive deformities ultimately require surgery.

Final Take-Home Message

Cavus foot is a high-arched deformity most commonly caused by neurological disease.

The deformity results from muscle imbalance and frequently progresses over time.

Accurate evaluation should include:

Neurological assessment
Clinical examination
Flexibility testing
Radiographic analysis

Treatment ranges from orthotics and bracing to complex reconstructive surgery depending on severity and underlying cause.

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