What is planovalgus foot deformity and how should it be evaluated and managed?

Planovalgus Foot Deformity: Definition, Evaluation, and Management

Definition

Planovalgus (pes planovalgus) is a three-dimensional foot deformity characterized by collapse of the medial longitudinal arch, hindfoot valgus alignment, and midfoot abduction. 1, 2 This deformity can range from flexible (arch present during non-weight-bearing) to rigid (persistent arch collapse regardless of weight-bearing status). 1

Clinical Evaluation

Initial Assessment

• Remove shoes and socks for bare foot inspection at every clinical visit to assess arch height, hindfoot alignment, and forefoot position. 3
• Distinguish flexible from rigid deformity by observing arch formation during tiptoeing or non-weight-bearing—flexible deformity shows arch restoration, while rigid deformity does not. 1
• Assess for associated conditions including posterior tibial tendon dysfunction (most common in adults), tarsal coalition, congenital vertical talus, neuromuscular disorders (cerebral palsy), and genetic syndromes. 1, 4

Risk Stratification

Planovalgus deformity significantly increases ulceration risk through abnormal pressure distribution and friction. 3 Patients with this deformity should be classified as moderate-to-high risk and require:

• Foot inspection every 1-3 months for high-risk patients (those with neuropathy, peripheral artery disease, or previous ulceration). 3
• Annual comprehensive foot evaluation including vascular assessment, neuropathy screening, and pressure distribution analysis. 3

Radiographic Assessment

Weight-bearing dorsoplantar and lateral radiographs are essential to quantify deformity severity and guide treatment. 2 Key measurements include:

• Lateral talocalcaneal angle (hindfoot valgus)
• Talonavicular coverage angle (midfoot abduction)
• Calcaneal pitch and lateral talometatarsal angle (arch collapse)
• Assessment for tarsal coalition or bony abnormalities 2

Four radiographic patterns exist: subtalar pes planus, midtarsal pes planus, mixed pes planus, and pes planocavus—each requiring tailored surgical approaches. 2

Management Approach

Conservative Management (First-Line)

All flexible planovalgus deformities without rigid components should be managed conservatively initially. 1

Therapeutic Footwear

• Prescribe shoes with sufficient width at metatarsophalangeal joints, adequate length (1-2 cm longer than foot), firm support, and adjustable features. 5
• Therapeutic footwear reduces ulcer risk in patients with foot deformities, neuropathy, or previous ulceration. 3
• Referral to a therapeutic footwear specialist is indicated for moderate-to-high risk patients. 3

Orthotic Intervention

• Custom or prefabricated orthoses redistribute plantar pressure and reduce pain. 5
• Cushioning insoles with appropriate padding reduce hyperkeratosis and pressure on medial structures. 5

Activity Modification and Physical Therapy

• Maintain healthy weight as obesity exacerbates deformity progression in children. 1
• Strengthening exercises and gait training improve foot musculature and functional outcomes. 5

Monitoring

• Asymptomatic children with flexible deformity require observation only, as most resolve with skeletal maturity. 1
• Podiatric assessment every 3-6 months for symptomatic or high-risk patients. 5

Surgical Management

Rigid planovalgus deformities require subspecialist referral and surgical consideration. 1, 4

Indications for Surgery

• Rigid deformity with persistent symptoms despite conservative management 1, 4
• Severe deformity with impending or actual skin ulceration 3
• Progressive deformity in ambulatory patients with neuromuscular conditions 6
• Significant functional impairment affecting mobility 3

Surgical Options Based on Deformity Pattern

For flexible/mild-to-moderate deformity:

• Calcaneal lengthening osteotomy (CLO) effectively corrects hindfoot valgus and restores arch height with preservation of joint motion. 6, 7
• CLO shows significant improvement in radiographic parameters and plantar pressure distribution, particularly in medial forefoot and hindfoot regions. 7

For severe/rigid deformity:

• Subtalar fusion or double arthrodesis (talonavicular and calcaneocuboid joints) provides definitive correction in severe cases. 6, 7
• Subtalar fusion is more effective for severe rigid deformities with marked subtalar valgus. 6
• Double arthrodesis improves lateral talocalcaneal angle correction and lateral forefoot pressure distribution better than CLO. 7

For Charcot neuro-osteoarthropathy with planovalgus:

• Surgical intervention during active Charcot phase should be considered when deformity causes impending ulceration, severe instability, intractable pain, or inability to immobilize in total contact cast. 3
• Realignment arthrodesis is the primary reconstructive technique, though complication rates are high. 3

Surgical Outcomes and Recurrence

• Both CLO and subtalar fusion show significant postoperative improvement in ambulatory children with cerebral palsy. 6
• Recurrence occurs in approximately 29% of cases, with higher rates in younger patients. 8, 6
• Medial column fusion is the primary salvage procedure for recurrent deformity. 6

Special Populations

Charcot Neuro-osteoarthropathy

Planovalgus deformity from Charcot foot represents a surgical emergency when skin integrity is threatened. 3 Valgus deformities of the hindfoot are poorly tolerated due to subcutaneous malleoli, leading to rapid ulceration and osteomyelitis risk. 3

Genetic Syndromes

Planovalgus occurs with high frequency in cardio-facio-cutaneous syndrome and 22q11.2 deletion syndrome. 3 These patients often require:

• Orthopedic referral at diagnosis 3
• Consideration of orthotics for nonspecific leg/foot pain 3
• Screening for associated musculoskeletal abnormalities 3

Critical Pitfalls to Avoid

• Never assume asymptomatic planovalgus is benign in high-risk patients—ulceration risk remains elevated even without pain. 3
• Do not delay surgical referral for rigid deformities—progressive collapse increases surgical complexity and recurrence risk. 1, 4
• Avoid immobilization alone for active Charcot with severe valgus deformity—early surgical stabilization prevents catastrophic ulceration. 3
• Do not perform bilateral simultaneous surgery without careful consideration—functional recovery requires at least one mobile foot. 6