rocker bottom foot

A rocker bottom foot (also known as a congenital vertical talus) is a congenital anomaly of the foot. It is characterized by a prominent calcaneus/heel and a convexly rounded sole.

Pathology

It results from a dorsal and lateral dislocation of the talonavicular joint.

Associations

Radiographic features

For assessment of the foot alignment abnormalities, it is important to perform weight-bearing images or an equivalent in neonates:

  • fixed equinus: plantarflexion of the calcaneus
  • vertical talus: plantarflexion of the talus (increased talocalcaneal angle)
  • irreducible dorsal subluxation or dislocation of the navicular
  • forefoot valgus: divergence of bases of the metatarsal heads on AP and superimposition of the metatarsal bones on the lateral view
  • long axis of the talus passes plantar to the metatarsal axis on lateral view and medial to the first metatarsal on AP view

The presence of a rocker bottom foot in an antenatal ultrasound scan is sometimes classified as a soft sign for aneuploidic anomalies .

Differential diagnosis

In the antenatal/neonatal period consider clubfoot.

In the adult period consider acquired rocker bottom deformity occurring secondary to: