July 18, 2024
Rocker bottom foot, Rigid Pes Planus, Congenital convex pes valgus

Congenital Vertical Talus is a condition in which there is dorsal subluxation/dislocation of navicular with equinus of the talus/ankle

Isolated idiopathic CVT < 50% cases

Bilateral cases: 50 %

Associated Syndromes:

  • Neuromuscular disorders
  • Sacral agenesis
  • Diastematomyelia
  • Myelodysplasia
  • Arthrogryposis

Trisomy:- 13, 15 and 18

Congenital Vertical Talus
Congenital Vertical Talus

Pathoanatomy

Hallmark: Dorsal subluxation/dislocation of navicular with equinus of the talus/ ankle (an essential component of deformity) and Equinus and Valgus of calcaneus and foot

Skin in the vertical talus (undersurface) is callosed due to weight-bearing by the talar head.

Oblique talus

Condition where all deformities are present but navicular can be reduced over talar head in plantar flexion

Tendon and capsule are contracted on the dorsal and lateral surface

Tendoachilllis, long toe extensors, peronei, talonavicular, and posterior ankle capsule are contracted

Tibialis anterior is shortened

Peronei , tibialis posterior, subluxated anteriorly

The orientation of the talus is vertical

So, articular cartilage is present over dorsum of talar head, Lateral translation and valgus of calcaneum, Misshaped calcaneal facet

Coleman classification:

Type I: Joint relation is normal

Type II: Subluxed/ displaced calcaneo-cuboidal joint

Lichtblau types:

  • Teratogenic
  • Neurogenic
  • Acquired

Clinical Features

  • Forefoot – Valgus
  • Heel – Valgus + Equinus

Rigid: Ankle plantarflexion restricted

The medial border is convex: Prominence of the talar head

Convexity persists during weight-bearing ( Unlike flexible flat foot)

Dimple at anterolateral aspects

Deep skin crease is present at the anterior aspect of the ankle

Long-standing cases: callosities is present on weight bearing head of the talus

Shoe wear: uncomfortable: long cases secondary Osteoarthritis sets in Foot become painful

Radiological Investigation:

Taken in [Supine position for infants], [Weight bearing film for older children]

Normal talocalcaneal angle (Kites) angle: 25-50 degree in AP

Talo-calcaneal angle: 30-55 degree in lateral

In CVT:

AP: talocalcaneal angle is INCREASED . (Subtalar valgus deformity)

Meary’s angle: (Talo-1st metatarsal angle): NEGATIVE (Normal: 0-20 degrees)

Talus is almost verticle and aligns parallel to the tibia

Normally long axis of the talus passes the lower 1/3rd of cuboid

In CVT: the long axis of the talus passes behind cuboid

Treatment

Aim: To obtain plantigrade foot, pain-free and normal-appearing foot

Reverse Ponseti

  • Pressure is applied to the medial part of the talus while the forefoot is abducted and plantigrade
  • This reduces joint
  • This position held by plantar cast
  • Combined with soft tissue lengthening
    • Tendoachillis
    • Peronei
    • EDL
    • Tibialis anterior
  • Sometimes, capsulotomy is needed
  • Archived position held for 5-6 weeks with joining transfixing K-wires with 5 degrees than 15 degrees dorsiflexion of the ankle in long leg cast
  • Then, Ankle foot orthosis for 2 years

15° of plantar flexion

15° adduction and midtarsal joint

At night, clubfoot-like brace with feet fixed at 6° for 12-14 hours

Surgical Treatment

Done at the earliest possible time (Before 6 months)

Indicated for:

  • Rigid, syndromic, and relapsed
  • Stiff

Aim:

  • Lengthening tight soft tissue structure and
  • Reduce dislocated joint (talonavicular joint reduction)

Approach:

  • Medial
  • Lateral
  • Cincinnati

Release of soft tissue done on order:

Lateral – Posterior – Anterior

Peronei – tendoachilis – EDL – Tibialis anterior with Z- Plasty

After Z- Plasty, the talonavicular joint is opened

In children over 2 years, transfer of one 1/2 of tibialis anterior to neck of talus done to maintain in a dorsiflexion position

Older children may require excision of the navicular to achieve the reduction

Salvage Surgery

  • Coleman subtalar arthrodesis
  • Triple arthrodesis

Post-operatively, solid AFO- 2 years, medial wedge in regular footwear

Complications

  1. Relapse
  2. Surgical complication
    • Skin necrosis
    • AVN of navicular and talus
  3. OA of foot
  4. Calcaneum deformity (Due to the excessive lengthening of tendon-Achilles and tight transferred tibialis anterior)

Summary of treatment of CVT depending upon age

1-4 years:

  • Open reduction and realignment of talonavicular, calcaneocuboid, and subtalar joints
  • navicular excision, partial talectomy, and decancellation of tarsal bones may be required for > 3 years of child
  • Lateral Column Lengthening

4-8 years:

  • Open reduction, soft tissue release, and extraarticular ( Grice-green) subtalar arthrodesis, sometimes intraarticular arthrodesis
  • A gap of 6-8 weeks is usually given between release and arthrodesis

>8 years:

  • Triple arthrodesis

See also: Developmental dysplasia of the hip (DDH)

See also: Congenital Talipus Equinovarus (CTEV)

See also: Legg-calve-Perthes disease (LCPD)