Talipes equinovarus is a fixed deformity with four components:
- Equinus (plantar flexion at ankle)
- Varus (hindfoot inversion)
- Adductus (forefoot medial deviation)
- Cavus (high medial arch)
Unilateral clubfoot
- More likely isolated
- Lower genetic yield
- Better prognosis
- Think positional or idiopathic first
Bilateral clubfoot
- Higher chance of underlying pathology
- Stronger association with:
- Aneuploidy
- Neuromuscular disease
- Syndromic conditions
True clubfoot vs positional
True clubfoot
- Foot stays inverted on repeated scans
- Tibia–foot angle abnormal
- Sole of foot seen in same plane as tibia
- Associated calf muscle hypoplasia postnatally
Positional foot
- Changes position during scan
- Normal ankle motion
- Often resolves later in pregnancy
Isolated clubfoot
Isolated clubfoot (most common)
- No other structural anomalies
- Normal growth
- Normal CNS and spine
- Normal fetal movements
Prognosis excellent
Non-isolated clubfoot (red flags)
- Spine: tethered cord, spina bifida
- Brain: ventriculomegaly, ACC
- Limbs: arthrogryposis, clenched hands
- Thorax: small chest
- Growth restriction
- Reduced fetal movements
Aneuploidy
More common with bilateral + other anomalies
- Trisomy 18 (classic)
- Trisomy 13
- Trisomy 21 (less common, usually with other markers)
Copy number variants
- 22q11.2 deletion
- Submicroscopic CNVs when clubfoot is part of a pattern
Single-gene disorders
Neuromuscular
- Spinal muscular atrophy
- Congenital myopathies
- Myotonic dystrophy
Clues:
- Reduced movements
- Polyhydramnios
- Arthrogryposis
Syndromic / connective tissue
- Distal arthrogryposis
- Larsen syndrome
- Multiple pterygium syndromes
Idiopathic / multifactorial
- Majority of isolated cases
- Polygenic + environmental factors
- Strong male predominance
Prognosis
Isolated clubfoot
- 90–95% walk normally
- Ponseti casting ± minor surgery
- Normal intelligence
- Normal quality of life
Unilateral often slightly easier to treat than bilateral.
Bilateral isolated clubfoot
- Still excellent outcomes
- Longer casting
- Slightly higher relapse rate
- Good long-term function
- Clubfoot must be fixed, not positional
- Bilateral = higher genetic yield
- Isolated clubfoot is a treatable orthopedic condition, not a neurodevelopmental diagnosis
Red flags
- Reduced fetal movements
- Arthrogryposis / joint contractures
- Limb shortening or multiple limb anomalies
- CNS abnormalities (VM, ACC, posterior fossa)
- Spinal anomalies
- Cardiac defects
- Growth restriction / polyhydramnios
ISOLATED CLUBFOOT
- No red flags above
- Normal movements
- Normal CNS, spine, heart
- Normal growth
Genetics yield
| Test | Expected diagnostic yield |
|---|---|
| Karyotype | <1% |
| CMA | 1–3% |
| Exome | <2% |
NON-ISOLATED / SYNDROMIC CLUBFOOT
RED FLAGS
- Neuromuscular (↓ movements)
- Skeletal dysplasia (patterned limb findings)
- Chromosomal / syndromic
Genetics yield
| Test | Expected diagnostic yield |
|---|---|
| Karyotype | 5–10% |
| CMA | 10–20% |
| Exome | 20–40% (highest with arthrogryposis) |
Genetics
- Offer CMA to all
- Consider exome if:
- Arthrogryposis
- Multiple anomalies
- Progressive contractures
Prognosis
- Determined by underlying diagnosis
- Foot correction may be incomplete
Counseling sentence
"The foot finding may be part of a broader condition, which determines prognosis more than the foot itself."