Polydactyly of the Foot Clinical Presentation

Updated: Oct 17, 2022
  • Author: Cara Novick, MD; Chief Editor: Jeffrey D Thomson, MD  more...
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History and Physical Examination

The patient may present in infancy or at a later date when cosmesis or shoe fit becomes a concern. Obtain a thorough family history, and exclude association with syndromes. Perform a thorough musculoskeletal examination to exclude any other congenital anomalies or signs that occur with known syndromes.



A morphologic classification of polydactyly was described by Venn-Watson (see the image below). [3]

The Venn-Watson classification of polydactyly is b The Venn-Watson classification of polydactyly is based on the anatomic configuration of the metatarsal and the duplicated bony parts.

The Venn-Watson classification is based on the configuration of the metatarsal, as follows:

  • Normal metatarsal with distal phalanx duplication
  • Block metatarsal
  • Y-shaped metatarsal
  • T-shaped metatarsal
  • Normal metatarsal shaft with a wide head
  • Duplicated ray

A first metatarsal bracket epiphysis (longitudinal epiphyseal bracket) may occur in preaxial polydactyly. [25]

Several decades later, Seok et al developed a classification system for polydactyly of the foot that was intended to help determine surgical plans and predict outcomes. [26]  This system consists of the following components:

  • Three characters (S, indicating syndactylism; A, indicating axis deviation; and M, indicating metatarsal extension
  • Three numbers (0, 1, and 2, indicating the degree of complexity of the polydactyly)

For example, the designation S1A1M2 in this system would indicate a case in which syndactylism to the adjacent toe was incomplete with the webbing involving less than half the length of the involved digits, the angulation was 15° or greater but less than 30°, and the metatarsal extension involved the shaft and more. [26]

Burger et al developed a classification system for medial foot polydactyly (the Rotterdam Foot Classification) that was based on the following four categories of anatomic features of the foot [27] :

  • Duplication type
  • Syndactyly
  • Presence of a hypoplastic ray
  • Deviation of the hallux