Congenital Vertical Talus -

Rare foot deformity- 1/10 000 live births
Characterised by a hindfoot in equinus. midfoot dorsiflexion forefoot abduction, resulting in midfoot dislocation through talonavicular joint
Rigid deformity with a convex plantar surface that forms a rocker-bottom deformity

50% of cases associated with neuromuscular and central nervous system disorders (myelomeningocele and distal arthrogryposis) or known genetics defects/syndromes
- aneuploidy of chromosomes 13 15 18. De Barsy, Costello and Rasmussen syndromes
- Of the 50% idiopathic cases, 20% have a positive family history with an autosomal dominant inheritance pattern- genetic link but no single genetic defect is responsible for all congenital vertical talus patients

Clinical Differentiation

Rigidity of deformity is the key to distinguishing between other conditions
If hindfoot equinus is not a clinical feature then its not vertical talus and is likely positional in nature

Coleman Classification
- Type 1- rigid dorsal dislocation of the talonavicular joint
- Type 2- dislocation of TNJ with dislocation/subluxation of calcaneocuboid joint

Ossification of the foot
- Hindfoot and metatarsals are ossified at birth
- Navicular, cuniforms and cuboid are not
  - Cuboid ossifies at first month of life
  - Cuneiforms age 2
  - Navicular ossify at 3 years
Need AP view and then 3 lateral views- maximal dorsiflexion, neutral and maximal plantar flexion
- if in the maximal plantar flexion views the first ray appears to reduce then the diagnosis is an oblique talus rather than vertical talus, with oblique talus being more ameniable to casting
Talocalcaneal angle
Tibiocalcaneal angle
Talar axis-first metatarsal base angle

In neonates can use serial casting (reverse ponsetti method) and manipulation to stretch the anterior skin and the ligamentous and soft tissues. Often not affective in isolation but is useful in stretching the soft tissues to make for a less invasive approach/incision at the time of surgery
- gentle manipulation of the foot into the desired position then applying the cast in that position
- Moving the foot into the corrected position after the cast is applied has a higher rate of cat slippage or skin problems.
Definitive surgical correction (open release) can be performed between ages 6-12 months, best outcomes if surgery is performed before 2 years.

Primary surgical management
- Single-stage:
  - Focus on dorsolateral soft tissue contractures, with less extensive dissection posteriorly
- Two-stage:
  - Stage 1- Lengthening the contracted dorsolateral tendons and capsule
  - Stage 2-
    - Reducing the talonavicular and subtalar joint complex (stabilization with Kirschner wire)
    - Lengthening achilles and peroneal tendons, posterolateral capsule release
Post operative casting until K wire removal, then can consider changing to boots and bars which is worn full time for 2 months, then at night time for 2 years to minimize risk of recurrence
Parents should be taught foot stretching exercises that emphasize ankle plantar flexion and foot adduction (suggest several times per day, ie at diaper changes)
In patients that can walk, daytime bracing can be commenced with a solid ankle-foot orthosis instead of the boot and bar system

Author Contributions

page written by Dr Cassandra Coetzee