Rocker bottom foot
A rocker bottom foot (also known as a congenital vertical talus) is a congenital anomaly of the foot. It is characterised by a prominent calcaneus/heel and a convex rounded sole.
It results from a dorsal and lateral dislocation of the talonavicular joint.
- aneuploidic syndromic
- non-aneuploidic non-syndromic
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 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 3.
In the antenatal/neonatal period consider clubfoot.
In the adult period consider acquired rocker bottom deformity occurring secondary to:
- 1. Mckie J, Radomisli T. Congenital vertical talus: a review. Clin Podiatr Med Surg. 2010;27 (1): 145-56. doi:10.1016/j.cpm.2009.08.008 - Pubmed citation
- 2. Russell JM, Peterson JJ, Bancroft LW. MR imaging of the diabetic foot. Magn Reson Imaging Clin N Am. 2008;16 (1): 59-70, vi. doi:10.1016/j.mric.2008.02.004 - Pubmed citation
- 3. www.rcogcourses.org.uk/topics/soft%20ultrasound%20markers.pdf