Congenital Talipes Equinovarus (CTEV)

Congenital talipes equinovarus, or club foot, is the commonest congenital deformity of the foot and a perennial favourite of NEET PG paediatric orthopaedics. It is a complex three-dimensional deformity present at birth in which the foot is twisted inward and downward, fixed in a position that cannot be passively corrected to neutral. Mastery of the CAVE components, the Pirani score, and the Ponseti method comfortably covers the bulk of what is asked.

Definition and terminology

"Talipes" derives from talus (ankle) and pes (foot); "equinovarus" describes the position—plantarflexed like a horse's hoof (equinus) and inverted (varus). The deformity is rigid, distinguishing true CTEV from positional/postural club foot (which is fully correctable passively and resolves with minimal intervention).

High-yield: Club foot is the most common congenital deformity of the foot. Incidence is roughly 1–2 per 1000 live births, with a male preponderance (~2:1). It is bilateral in ~50% of cases.

The CAVE components

The deformity has four classic components, best remembered by the mnemonic CAVE:

Letter	Component	Description	Joint/level
C	Cavus	High medial longitudinal arch (plantarflexed first ray)	Midfoot
A	Adductus	Forefoot adduction (deviated medially)	Midfoot/forefoot
V	Varus	Heel/hindfoot inversion	Subtalar joint
E	Equinus	Ankle plantarflexion	Ankle joint

High-yield: In the Ponseti method the equinus is corrected LAST, after cavus, adductus and varus have been addressed. Correcting equinus too early risks a rocker-bottom deformity (iatrogenic dorsal break in the midfoot). The order of correction follows the sequence Cavus → Adductus → Varus → Equinus.

Classification

Club foot is broadly divided into idiopathic and secondary (non-idiopathic) types—a distinction that matters greatly for prognosis and management.

Type	Features	Response to Ponseti
Idiopathic (typical)	Otherwise normal child; commonest variety	Excellent; most correct in 5–6 casts
Teratologic	Associated with neuromuscular/syndromic disease—myelomeningocele, arthrogryposis, diastrophic dysplasia	Rigid, resistant, high relapse, often need surgery
Positional/postural	Intrauterine moulding; fully passively correctable	Corrects with stretching/few casts
Syndromic	Part of a recognised syndrome	Variable

High-yield: A rigid, resistant club foot with a deep posterior crease that does not respond to casting should raise suspicion of a teratologic cause—examine the spine for myelomeningocele and the joints for arthrogryposis.

The Dimeglio and Pirani scoring systems quantify severity; Pirani is the most clinically used and most examined.

Etiology and pathophysiology

The exact cause is unknown (idiopathic) but is multifactorial, with genetic and environmental contributions:

• Genetic: Increased risk with positive family history; if one child is affected, sibling risk rises ~20–30 fold. PITX1 gene implicated. Polygenic inheritance.
• Environmental: Maternal smoking (strong association, especially with positive family history), oligohydramnios, intrauterine packing.
• Neuromuscular theory: Imbalance between weak peroneal (everter) muscles and strong tibialis posterior/gastrocsoleus (invertor/plantarflexor) pull.
• Arrest of fetal development and primary germ-plasm defect in the talus (Irani–Sherman) are older proposed theories.

The pathological hallmark is medial and posterior soft-tissue contracture (tibialis posterior, FHL, FDL, deltoid ligament, posterior capsule) together with bony deformity. The talus is plantarflexed, its neck medially and plantarward deviated, and the navicular is medially displaced, articulating with the medial malleolus. The calcaneus is in varus and equinus and lies beneath the talus rather than lateral to it.

High-yield: The navicular is displaced medially, lying close to the medial malleolus, and the talar head becomes prominent laterally—a key palpable landmark used to assess correction during Ponseti casting.

Clinical features

Diagnosis is clinical and obvious at birth:

• Foot turned inward and downward; forefoot adducted, hindfoot in varus, ankle in equinus, with a cavus arch.
• Medial and posterior skin creases; deeper creases indicate greater rigidity and worse prognosis.
• Smaller foot and calf (calf-muscle wasting) on the affected side; mild leg-length and shoe-size discrepancy that persists even after successful treatment—parents must be counselled about this.
• The deformity is rigid—it cannot be passively over-corrected to neutral (unlike postural club foot).
• In a walking child (neglected case): weight-bearing on the dorsolateral border of the foot with callosity/bursa formation there.

Examination flow: Confirm rigidity → assess each CAVE component → score with Pirani → examine the spine (sacral dimple, hairy patch, swelling → spinal dysraphism), hips (associated DDH), and all four limbs/joints (arthrogryposis), and a general systemic exam to exclude syndromes.

Pirani scoring

The Pirani score is a simple, validated 6-point system used to grade severity and monitor response to Ponseti casting. It has two parts of three signs each, every sign scored 0 (normal), 0.5 (moderate), or 1 (severe).

Hindfoot contracture (HFCS)	Midfoot contracture (MFCS)
Posterior crease	Curvature of lateral border of foot
Emptiness of heel (empty heel)	Severity of medial crease
Rigidity of equinus	Lateral part of head of talus (coverage)

• Total score range: 0 to 6 (HFCS 0–3 + MFCS 0–3).
• Higher score = more severe deformity.

High-yield: Pirani total = 6 components; max score 6. A Pirani score ≥ 5 (or a high HFCS) predicts a likely need for Achilles tenotomy. The score is used before each cast to track correction.

Diagnosis and investigations

• Clinical diagnosis is sufficient; CTEV is recognised on inspection at birth.
• Antenatal ultrasound can detect club foot from ~the 2nd trimester (around 18–20 weeks)—useful for parental counselling and to look for associated anomalies.
• Radiographs are not needed for routine diagnosis but help assess severity/correction in older children and pre/post surgery. Key angles on a simulated weight-bearing (stress dorsiflexion) lateral and AP view:

Radiographic angle	Normal	In CTEV
Talocalcaneal (Kite) angle – AP	20–40°	Decreased (parallelism of talus & calcaneus)
Talocalcaneal angle – lateral	35–50°	Decreased
Talo–first metatarsal angle	0–20°	Negative/abnormal

High-yield: Parallelism of the talus and calcaneus (reduced Kite angle) on radiograph indicates hindfoot varus—the radiographic signature of club foot. Ossification of the navicular is delayed, so soft-tissue/cartilage relationships are inferred from talar and calcaneal axes.

Management — the Ponseti method (treatment of choice)

Treatment should begin as early as possible, ideally within the first 1–2 weeks of life, while ligaments and tissues are still pliable. The Ponseti method is the gold-standard, first-line treatment worldwide and has largely replaced extensive surgical release.

Ponseti technique — stepwise

1. Manipulation and serial casting: Weekly gentle manipulation followed by an above-knee (long-leg) plaster cast with the knee flexed ~90°. Correction sequence follows CAVE in reverse priority—cavus first (supinate forefoot, elevate first ray) → adductus and varus together (abduct the foot under a stabilised talar head, with counter-pressure on the lateral talar head, NOT on the calcaneocuboid joint) → and equinus last.
2. Casts: Typically 5–6 casts over 5–6 weeks achieve correction in idiopathic cases. The foot is abducted up to ~60–70° of external rotation relative to the frontal plane of the tibia.
3. Percutaneous Achilles tenotomy: Needed in ~80–90% of patients to correct residual equinus once forefoot/midfoot is corrected (i.e., when the foot abducts well but dorsiflexion is still < ~10–15°). A final cast is kept for ~3 weeks post-tenotomy to allow tendon regeneration.
4. Bracing (maintenance): A foot abduction orthosis—the Denis Browne splint (boots on a bar)—is the cornerstone of relapse prevention. Worn 23 hours/day for the first ~3 months, then night-time and naptime (~12–14 h/day) until age 4–5 years.

High-yield: Counter-pressure during Ponseti casting is applied on the LATERAL HEAD OF THE TALUS (the fulcrum), never on the calcaneocuboid joint—pressure there blocks correction and causes a "bean-shaped" foot. Equinus is corrected last, by tenotomy if needed.

High-yield: Non-compliance with the Denis Browne (foot abduction) brace is the single most common cause of relapse after successful Ponseti correction. Compliance counselling is critical.

Brace details — Denis Browne splint

• Boots set in ~70° external rotation on the affected side (~40° on a normal foot in bilateral cases), with slight dorsiflexion, mounted on a bar at shoulder width.
• It is a dynamic abduction orthosis, not a static cast.

Surgical management

Surgery is reserved for failed conservative treatment, neglected/resistant cases, teratologic feet, and relapses not amenable to repeat casting.

• Soft-tissue release — Posteromedial soft tissue release (PMSTR) for the rigid foot (releases posterior and medial contractures, lengthens tibialis posterior, FHL, FDL, Achilles). Historically common but now far less so because of overcorrection/stiffness/pain in later life.
• Tendon transfer — Tibialis anterior tendon transfer to the 3rd cuneiform (lateral cuneiform) for dynamic supination relapse in a child usually > 2.5–3 years with ossified lateral cuneiform. This is a very examinable point.
• Bony procedures (older children/recurrence):
  • Dwyer's lateral closing-wedge calcaneal osteotomy for residual heel varus.
  • Dilwyn-Evans procedure (lateral column shortening, calcaneocuboid fusion) for relapsed/resistant club foot.
  • Lichtblau procedure (distal calcaneal/lateral column shortening).
  • Triple arthrodesis (subtalar + talonavicular + calcaneocuboid fusion) for the older child/adolescent (> 10–12 yrs) with a rigid, painful, neglected foot.
• Ilizarov / JESS distraction for severe neglected deformity in older children—gradual differential distraction.

High-yield: Tibialis anterior tendon transfer to the lateral cuneiform is the operation for dynamic supination relapse; Dwyer's osteotomy corrects residual hindfoot varus; triple arthrodesis is the salvage for the older neglected/rigid foot.

The "French" (functional) method

An alternative non-operative regime using daily physiotherapy, stretching, taping and continuous passive motion. It is more labour-intensive and less widely adopted than Ponseti, which remains the global standard. Worth knowing it exists as a distractor option.

Relapse and its management

Relapse occurs in up to a third of cases, most often due to brace non-compliance. A stepwise approach:

Detect early relapse → repeat Ponseti casting (re-manipulation) → repeat Achilles tenotomy if equinus recurs → tibialis anterior transfer for dynamic supination (age ~3 yrs) → bony procedures for fixed deformity in older children.

Signs of relapse: loss of dorsiflexion, recurrence of varus/adductus, dynamic supination during gait (forefoot supinates in swing), and increasing Pirani score.

Complications

• Of neglected/untreated club foot: weight-bearing on the dorsolateral foot, callosities and adventitious bursae, gait disturbance, social/cosmetic morbidity, leg/foot atrophy.
• Of treatment:
  • Rocker-bottom deformity from premature/forced dorsiflexion before midfoot correction.
  • Bean-shaped (skew) foot from incorrect cuboid counter-pressure.
  • Overcorrection, stiffness, weakness and arthritis/pain after extensive surgical release in later life (the chief reason Ponseti superseded surgery).
  • Cast-related skin pressure sores; tenotomy bleeding (rare).
• Residual findings even after success: smaller foot, calf wasting, mild stiffness—normal-looking, functional, plantigrade, painless foot is the goal, not an anatomically perfect one.

Associations to remember

• Developmental dysplasia of the hip (DDH) — examine the hips in every club foot.
• Myelomeningocele / spinal dysraphism — examine the spine.
• Arthrogryposis multiplex congenita — multiple rigid joint contractures.
• Diastrophic dysplasia, Streeter dysplasia (constriction band), Larsen syndrome.
• Tibial hemimelia/deficiency.

Key differentials

Condition	Distinguishing feature
Postural/positional club foot	Fully passively correctable; no fixed bony deformity
Metatarsus adductus	Only forefoot adduction; hindfoot normal, no equinus; usually resolves spontaneously
Congenital vertical talus ("rocker-bottom" / Persian-slipper foot)	Rigid dorsiflexed forefoot, convex sole, dorsally dislocated navicular; the opposite of cavus
Z-foot / skew foot	Forefoot adduction + hindfoot valgus
Calcaneovalgus foot	Foot dorsiflexed and everted; usually postural, resolves

High-yield: Distinguish metatarsus adductus (forefoot only, normal heel, benign) from CTEV (all four CAVE components, rigid). And distinguish congenital vertical talus (convex "rocker-bottom" sole, rigid dorsiflexion) from CTEV (equinus + cavus).

Recently asked / exam angle

• CAVE expansion and which component is corrected last in Ponseti (equinus).
• Site of counter-pressure during Ponseti manipulation (lateral head of talus; never the calcaneocuboid joint).
• Commonest cause of relapse (Denis Browne brace non-compliance).
• Pirani score total/components (max 6; hindfoot + midfoot, three signs each).
• Treatment of choice = Ponseti method; percutaneous Achilles tenotomy needed in ~80–90%.
• Tibialis anterior transfer to lateral cuneiform for dynamic supination relapse.
• Dwyer's osteotomy for residual heel varus; triple arthrodesis for old neglected foot.
• Idiopathic vs teratologic distinction; teratologic causes (myelomeningocele, arthrogryposis) are rigid and resistant.
• Radiographic Kite (talocalcaneal) angle is decreased; talus–calcaneus parallelism.
• Position of foot in Denis Browne splint (external rotation/abduction with dorsiflexion).
• Associated conditions (DDH, spinal dysraphism) and the need to examine spine and hips.

Rapid revision

1. Club foot = most common congenital foot deformity; ~1–2/1000; male 2:1; 50% bilateral.
2. Components = CAVE — Cavus, Adductus, Varus, Equinus.
3. Ponseti correction order: cavus → adductus/varus → equinus (last).
4. Counter-pressure on the lateral head of the talus, never the calcaneocuboid joint.
5. Treatment of choice = Ponseti serial casting (above-knee casts), ~5–6 casts.
6. Percutaneous Achilles tenotomy in ~80–90% for residual equinus; cast 3 weeks after.
7. Denis Browne (foot abduction) splint maintains correction till age 4–5 yrs; brace non-compliance = commonest cause of relapse.
8. Pirani score max 6 (hindfoot 3 + midfoot 3); used before each cast.
9. Radiograph: decreased talocalcaneal (Kite) angle, talus–calcaneus parallelism, delayed navicular ossification.
10. Tibialis anterior transfer to lateral cuneiform for dynamic supination relapse (~age 3).
11. Dwyer's osteotomy → residual heel varus; Dilwyn-Evans / triple arthrodesis → neglected older foot.
12. Teratologic club foot (myelomeningocele, arthrogryposis) is rigid, resistant, relapse-prone; always examine spine and hips (DDH).