Pes cavus, commonly called a high-arched or “claw” foot, is a structured deformity in which the longitudinal arch of the foot is abnormally elevated, producing a relatively stiff foot with increased pressure under the heel and forefoot. Although it can be an isolated, idiopathic variant, pes cavus is often a clinical sign of underlying neuromuscular disease, and its management must therefore address both the foot morphology and the causative pathology.
Definition and Classification
Pes cavus is defined as an exaggerated elevation of the medial longitudinal arch, visible in the sagittal plane, and is often accompanied by associated deformities such as hindfoot varus, forefoot adduction, and plantar flexion of the first ray. The terms “pes cavus” and “pes cavovarus” are frequently used interchangeably, though cavovarus implies a triplane deformity with varus of the hindfoot and adduction of the forefoot superimposed on the cavus component.
Three main subtypes are commonly described: anterior cavus, posterior cavus, and mixed cavus. Anterior cavus is associated with a plantar-flexed first ray and forefoot pronation, while posterior cavus is dominated by a calcaneal pitch increase and hindfoot varus; mixed cavus combines features of both. In clinical practice, the distinction is important because it guides both biomechanical assessment and surgical planning.
Epidemiology and Aetiology
In adults, the prevalence of pes cavus is estimated at approximately 10–29%, with no clear gender predominance. Many cases are idiopathic or familial, but a significant proportion are acquired and linked to neurological or musculoskeletal conditions.
Neurological aetiologies include:
- Hereditary motor and sensory neuropathies, particularly Charcot–Marie–Tooth disease
- Spinal cord disorders such as spinal dysraphism, tumors, or trauma
- Upper motor neuron conditions like cerebral palsy or stroke
- Peripheral nerve lesions, for example from compartment syndrome or trauma
Non-neurological causes include congenital deformities (e.g., clubfoot residual deformity), trauma with malunion, inflammatory conditions, and muscle imbalances secondary to local pathology. Importantly, the presence of a rigid, progressively worsening cavus foot in a child or young adult should prompt investigation for an underlying neuromuscular disorder.
Clinical Features and Symptoms
Patients with pes cavus typically present with:
- Pain localized to the heel, lateral forefoot, and sometimes the arch, due to focal overload
- Recurrent ankle sprains and a sense of instability, as the high arch reduces the contact area and compromises shock absorption
- Clawing or hammertoes, caused by imbalance between intrinsic and extrinsic muscles of the foot
- Difficulty with footwear, as the high arch and rigid foot shape can create pressure points and poor fit.
Gait abnormalities may include a shortened stance phase, increased lateral loading, and a tendency to “stiff-knee” gait in more severe neuromuscular cases. In children, parents may note that the child walks on the outer border of the foot or has frequent “falling over” of the ankle.
Assessment and Diagnosis
A comprehensive assessment begins with a detailed history, including family history of neuropathy, developmental milestones, and progression of the deformity. Neurological examination should evaluate distal muscle strength, tone, reflexes, and sensory function, as subtle signs of neuropathy may be present even when the foot deformity is the most obvious feature
Physical examination focuses on:
- Arch height and flexibility: a rigid cavus suggests a more established or neuromuscular cause
- Hindfoot position: varus is common and may be fixed or reducible
- Forefoot alignment: adduction and pronation are frequent
- Toe posture: claw toes indicate intrinsic weakness or imbalance
- Muscle bulk and tendon tightness, particularly the Achilles and plantar fascia.[acnr.co]
Radiographic evaluation includes weight-bearing foot X-rays to measure calcaneal pitch, first-ray angle, and other indices of arch elevation and hindfoot/forefoot alignment. In suspected neuromuscular cases, further investigations such as electromyography (EMG), nerve conduction studies, or genetic testing may be warranted to identify the underlying condition
Management Principles
Management of pes cavus is guided by the severity of the deformity, the presence of symptoms, the flexibility of the foot, and the underlying aetiology. The overarching goals are to reduce pain, improve function and stability, prevent progression, and, where possible, address the causative condition.
Conservative Management
Conservative measures are the first line of treatment for mild to moderate, flexible deformities:
- Orthotic devices: Custom foot orthoses with appropriate arch support, heel cupping, and forefoot relief can redistribute pressure, improve stability, and reduce pain. In neuromuscular cases, orthoses may also need to accommodate claw toes or varus alignment.[
- Footwear modification: Shoes with a supportive midsole, adequate cushioning, and a wide toe box help accommodate the high arch and clawed toes while reducing lateral overload.
- Physical therapy: Targeted stretching of the Achilles tendon and plantar fascia, alongside strengthening of intrinsic foot muscles and hip stabilizers, can improve flexibility and dynamic control. Gait retraining may be beneficial in cases with significant instability.
Conservative management is often insufficient for rigid, severe deformities or when there is progressive neurological deterioration, but it remains central in the long-term management of many patients.
Surgical Management
Surgery is indicated when conservative measures fail, when the deformity is markedly rigid, or when there is significant functional impairment or recurrent injury. The choice of procedure depends on the subtype of cavus, the site of the deformity, and the underlying pathology.
Common surgical options include:
- Soft-tissue procedures: Tendon transfers (e.g., flexor digitorum longus to first metatarsal) and lengthening of tight structures (Achilles, plantar fascia) to correct muscle imbalance and improve alignment.
- Osteotomies: Calcaneal osteotomies to reduce hindfoot varus; first-ray elevating osteotomies to correct plantar flexion of the first metatarsal; and midfoot or forefoot osteotomies to address adduction and arch elevation.
- Arthrodesis: In severe, rigid deformities, especially in the context of neuromuscular disease, fusion of selected joints (e.g., subtalar or triple arthrodesis) may be necessary to achieve a stable, plantigrade foot.
Surgical planning must be carefully integrated with the management of the underlying neuromuscular condition, as recurrence or progression may occur if the primary disease is not addressed.
Pes cavus is not merely a structural variant of the foot but a potentially significant clinical sign that warrants thorough evaluation for underlying neuromuscular pathology. Its management requires a nuanced combination of biomechanical understanding, neurological assessment, and tailored treatment ranging from orthotics and physical therapy to complex reconstructive surgery. For podiatrists and allied professionals, recognizing the patterns of cavus deformity, understanding its subtypes, and integrating conservative and surgical options within a broader diagnostic framework are essential to optimising outcomes for patients with this challenging condition.