Definition
Congenital Talipes Equinovarus
Congenital abnormality of the foot characterised by
- hindfoot equinus & varus
- forefoot Adduction
- midfoot Supination
Latin: talus - ankle / pes - foot / equinus - horse like
Clinical
Foot
- pipe stem calf
- short wide foot
- small heel
- curved lateral border
- short first ray ray
Short T Achilles
LLD
ER torsion tibia
Epidemiology
1:1000 live births
- 1/1000 Caucasian
- 5/1000 Polynesians
- 0.5/1000 Asian
Boys 2:1
Bilateral 30-50%
Genetics
Twin studies
- 33% risk in monozygotic twins
- 3% dizygotic twins
- i.e. is not just the placental environment
Sibling or parent
- 3% chance
- 30x increased risk
Sibling and parent
- 10 - 20% risk
Deletion on chromosome 2
Associations
Spina bifida & arthrogryposis (teratogenic)
Plus
- cerebral palsy
- muscular dystrophies
- spinal muscular atrophy
Theories of pathogenesis
1. Fetal development arrest in fibular phase
- during first and second months leg and foot coplanar
- by beginning of third month foot is in 90o of equinus, has supinated & adducted with plane at right angles to leg
- by the middle of the 3rd month the equinus has corrected
- by the end of the third month the supination and adduction has corrected to the adult position
- Bohm postulated arrest in the first phase in week 5
2. Retracting fibrosis (Ippolito and Ponseti)
- decrease in size & number of muscle fibres in posteromedial muscles
- ? fibrous tissue in muscles, tendon sheaths & surrounding fascia
- marked shortening and thickening of the tibionavicular and plantar calcaneonavicular ligaments
3. Neurogenic theory
- minor innervation changes in posterior muscles
- subsequent fibrosis and shortening
4. Myogenic theory
- myofibroblasts in medial fascia
5. Vascular theory
- anterior tibial artery / dorsalis pedis frequently missing
Pathology
All tissues in foot abnormal
- bony / muscle / ST / vascular
Bony deformities
Talus
- primary deformity
- equinus
- medial deviation of head and neck of talus
- external rotation of body of talus in mortise
- narrow neck & hypoplastic head due to lack of development of articular cartilage on lateral surface of head
Os Calcis
- equinus
- medial rotation
- long axes of talus & os calcis are parallel in sagittal & transverse planes
Navicular
- subluxed medially against medial malleolus
Cuboid
- medial column subluxed medially and adducted
- lateral & medial columns conjoined therefore cuboid subluxed medially also
Metatarsals
- adductus but minor compared to talonavicular deformity
Soft Tissues
Plantar fascia & intrinsics contracted
- long & short plantar ligaments
- contracture plantar fascia
- creates cavus
Tendons short
- T Achilles, T Posterior, FHL and FDL short
Ligaments short
- deltoid
- spring
- calcaneofibular ligament
- posterior talofibular ligament
- bifurcate
Joint capsules contracted
- posterior ankle joint
- posterior subtalar joint
- talonavicular joint
- calcaneocuboid joint
Muscles atrophied
Classification
A. Postural
- passive correction possible
- usually corrects spontaneously within days / weeks
- well defined heel, no calf atrophy
- relatively normal foot size
- no transverse medial skin crease
Mild - nearly fully correctable
Moderate - partially correctable
Severe - slightly correctable
B. Rigid
- uncorrectable
- small bean shaped foot, transverse crease, tight skin, atrophic calf
- heel difficult to palpate due to overlying fibrofatty tissue
C. Teratogenic talipes
- associated with spina bifida & arthrogryposis
- prognosis is much worse than idiopathic
Pirani Score
Pirani scoring system (0, 1/2, 1) (total out of 6)
Look (3)
- posterior crease / medial crease / lateral curvature
Feel (2)
- head of talus (anterior to lateral malleolus)
- empty heel
Move (1)
- DF range
Can be used to predict likelihood of needing TA tenotomy
Clinical Features
Look
Deformity / CAVES
Cavus - relative pronation of forefoot c.f. hindfoot
Adduction - forefoot
Varus - heel
Equinus - heel
Supination - midfoot
Posterior / medial crease
Curved lateral border of foot
Calf atrophy
Walk older child
Dynamic supination - require T anterior transfer
Metatarsus adductus
Foot progression angle - tibial torsion
ROM
DF
Eversion
Feel
Empty heel
Palpable talus - devils thumbprint anterior to lateral malleolus
Navicular fixed to medial malleolus
Os calcis fixed to the lateral malleolus
Exclude
- spinal dysraphism - look at spine
- arthrogryposis
- neuromuscular disorders
Rotational Profile
X-ray
Usually not indicated
Ossification
- calcaneal & talus ossification centres are present at birth
- cuboid appearing by 6 months
- navicular will not appear until 2-4 years
Angles
AP talocalcaneal angle / Kite's angle
- ankle DF 15° & tube at 30° from vertical
- long axis talus parallel long axis of calcaneum
- normal 20-40°
- <20° hind foot in varus / clubfoot axes approach parallel
Lateral talocalcaneal angle
- long axis of talus parallel to long axis of calcaneum
- normal 25-50°
- < 25° indicates hindfoot in equinus
- clubfoot axes are parallel or negative
Talo-1st metatarsal angle / AP
- long axis of talus to long axis of 1st metatarsal
- normal 5-15° abduction
- clubfoot 0° to negative