Clubfoot — Ponseti Technique

Congenital talipes equinovarus (CTEV), commonly known as clubfoot, is one of the most common congenital musculoskeletal deformities. It is characterised by a rigid, complex three-dimensional foot deformity present at birth. The Ponseti technique has revolutionised its management and is now the universally accepted gold standard treatment worldwide, replacing extensive surgical releases that were associated with high rates of stiffness, pain, and long-term dysfunction.

• Incidence: approximately 1 in 1000 live births; bilateral in 50% of cases
• Male:female ratio: 2:1
• Aetiology: multifactorial — genetic predisposition (10–25% family history), intrauterine positioning, neuromuscular abnormalities; true idiopathic CTEV most common
• Associated conditions: spina bifida, arthrogryposis, myelomeningocele — these syndromic/neurogenic clubfeet are more resistant to treatment and have higher recurrence rates
• Natural history without treatment: severe functional disability — unable to bear weight normally on plantigrade foot; lifelong gait impairment
• Pirani score: most widely used clinical scoring system — grades severity 0–6 (hind foot and mid foot subscores of 0–3 each); guides treatment and predicts number of casts required

Clubfoot is a complex three-dimensional deformity involving the entire foot and lower leg. Understanding each component and its correction sequence is fundamental to the Ponseti technique.

• Mnemonic CAVE — the four components of clubfoot: Cavus, Adductus, Varus, Equinus
• Cavus: high medial arch; pronation of the forefoot relative to hindfoot — corrected first by supinating the forefoot to align with hindfoot
• Adductus: metatarsal adduction; medial deviation of forefoot — corrected by abducting the foot
• Varus: heel varus (inverted subtalar joint); corrected simultaneously with adductus
• Equinus: fixed plantar flexion at ankle; corrected last — most resistant; requires Achilles tenotomy in majority of cases
• The talus is the key deformed bone — medially and plantarward displaced; navicular displaces medially onto talar neck; calcaneum internally rotated and in varus
• All deformities are centred on the talonavicular joint — correction of this joint unlocks the entire foot

The Ponseti method exploits the remarkable plasticity of neonatal connective tissue. Serial manipulation and casting gradually corrects the deformity in a specific sequence. Treatment should begin as early as possible — ideally within the first week of life.

Correction Sequence:

• Correction order: Cavus → Adductus + Varus → Equinus (last)
• Step 1 — Cavus correction: supinate the forefoot to align it with the hindfoot; do NOT pronate — this worsens the deformity by locking the calcaneum under the talus
• Step 2 — Adductus and Varus: abduct the foot externally with the thumb over the lateral talar head as a fulcrum; calcaneum abducts beneath the talus; foot moves toward external rotation
• Step 3 — Equinus: corrected last after achieving 70° of external rotation; dorsiflexion attempted — if <10–15° achieved, Achilles tenotomy performed
• Casts applied weekly (or bi-weekly in older infants); long leg cast in 90° knee flexion prevents cast slippage; average 5–6 casts required (range 4–8)
• The talar head is the fulcrum: counter-pressure is applied over the lateral talar head during abduction — never over the calcaneocuboid joint (will cause bean-shaped foot deformity)

• Required in approximately 80–90% of idiopathic clubfeet — the Achilles tendon is the primary restraint to dorsiflexion after other deformities are corrected
• Performed percutaneously under local anaesthesia in clinic or under general anaesthesia in theatre depending on age and preference
• Technique: medial or lateral approach at the tendon insertion; tenotome passed deep to tendon; complete division confirmed by sudden release and palpable gap
• Post-tenotomy: final cast applied immediately in maximum dorsiflexion (15°) and 70° external rotation; maintained for 3 weeks while tendon regenerates
• Complications: incomplete tenotomy (most common), neurovascular injury (sural nerve, posterior tibial artery), skin injury — all rare in experienced hands
• Tendon regenerates completely within 3 weeks — this is the biological basis for the 3-week final cast

Bracing after Ponseti casting is the most critical phase for long-term success. Recurrence is almost entirely due to non-compliance with bracing. This must be clearly communicated to parents at the outset.

• Denis Browne bar with open-toe boots: feet set at 60–70° external rotation on affected side; 45° on normal side (bilateral: both at 70°); bar width = shoulder width
• Bracing protocol: 23 hours/day for first 3 months, then nights and naps until age 4–5 years
• Recurrence rate with good compliance: approximately 5–10%; with poor compliance: up to 80%
• Parental education is paramount — compliance is the single most modifiable determinant of outcome
• Common reasons for brace failure: skin irritation, improper fitting, parental fatigue — regular clinic review and support essential

• Recurrence most commonly presents as dynamic supination during gait — caused by tibialis anterior overactivity relative to peroneals
• Tibialis anterior tendon transfer (TATT): transfer to the third cuneiform (lateral transfer) — indicated for dynamic supination after skeletal maturity or walking age; corrects muscle imbalance; prevents relapse without needing repeat casting in older children
• TATT indication: child walking age or older (typically >2.5 years); dynamic supination confirmed; Pirani score relapse after initially successful Ponseti treatment
• Repeat Ponseti casting: effective for recurrence in children under 2.5 years — regain correction then reapply bracing protocol rigorously
• Posterior tibial tendon: can also contribute to recurrence — occasionally transferred anteriorly in resistant cases
• Extensive posterior medial release (PMR): previously the standard surgical treatment — largely abandoned due to high rates of stiffness, overcorrection, pain, and early arthritis; reserved for failed Ponseti in syndromic/neurogenic cases only

• Ponseti technique: excellent long-term results — plantigrade, pain-free, functional foot in 90–95% when treatment initiated early and bracing complied with
• Cosmesis: foot may appear slightly smaller and calf slightly thinner than contralateral — acceptable; does not impair function
• Activity levels: normal sporting activity and adult function expected in well-treated idiopathic clubfoot
• Syndromic/neurogenic clubfeet (arthrogryposis, spina bifida): more resistant; higher recurrence; may ultimately require surgical release despite Ponseti attempts
• Long-term follow-up to skeletal maturity recommended — monitor for recurrence, muscle imbalance, and footwear requirements

• Neglected clubfoot in older children or adults: Ponseti casting still effective up to age 6–7 years with appropriate modifications; adults require extensive surgical correction (triple arthrodesis, talectomy, Ilizarov distraction); outcomes significantly worse with increasing age at treatment
• The bean-shaped foot (iatrogenic deformity): caused by incorrect counter-pressure over the calcaneocuboid joint rather than the talar head during casting; produces midfoot abduction with persistent forefoot adductus and hindfoot valgus; very difficult to correct; prevention requires precise technique
• Arthrogrypotic clubfoot: extremely rigid; requires more casts; Achilles tenotomy alone may not achieve equinus correction — percutaneous posteromedial release or open Achilles lengthening may be required; talectomy in resistant cases
• Atypical clubfoot (Morcuende classification): deep crease across sole, short stubby foot, hyperplantar flexion — Ponseti modification required: supinate forefoot more aggressively; tenotomy earlier; be aware of this variant to avoid mis-treatment
• TATT surgical technique: split vs whole transfer debate — whole tibialis anterior transfer to 3rd cuneiform gives reliable correction of dynamic supination with minimal donor site morbidity; split transfer used in some centres; both effective

• CAVE: Cavus, Adductus, Varus, Equinus — correction order: Cavus first, Equinus last
• Counter-pressure on lateral talar head — NOT calcaneocuboid joint (causes bean-shaped foot)
• Achilles tenotomy required in 80–90%; final cast 3 weeks at 15° dorsiflexion and 70° ER
• Denis Browne bar: 60–70° ER affected side; 45° normal side; 23 hours/day for 3 months then nights until age 4–5
• Recurrence = almost always due to brace non-compliance — compliance is the single most important factor
• TATT: tibialis anterior to 3rd cuneiform — for dynamic supination after walking age (>2.5 years)
• PMR (extensive posterior medial release): largely abandoned — high stiffness, pain, and arthritis rates
• Syndromic/neurogenic clubfoot: more resistant, higher recurrence — arthrogryposis, spina bifida
• Average 5–6 casts for idiopathic clubfoot; more for syndromic
• Pirani score 0–6: guides severity and predicts number of casts needed