Learning Radiology xray montage



General Considerations

  • A duplication abnormality in which there are more than five fingers or toes
  • May be unilateral or bilateral
  • May occur on the
    • Ulnar side (most common) – also called postaxial polydactyly
      • Most commonly, a rudimentary finger consisting only of a terminal phalanx
      • More common in African-Americans where it is usually an isolated abnormality; in Caucasians, it is usually part of a syndrome
      • In 14%, it is an autosomal dominant disorder with variable penetrance
      • More frequent in males
    • Radial side (less common) – also called preaxial polydactyly
      • Most frequent in Indian populations
      • May vary from small skin fold to duplicated digit
    • Centrally (least common)
      • Extra digit occurs on index, middle or ring finger, the index finger being the most common
      • May be associated with syndactyly


  • May occur sporadically or part of syndrome; some, but not all, include
    • Ellis-van Creveld – bilateral and postaxial
    • Down
    • Holt-Oram
    • Fanconi
    • Basal cell nevus
    • VATER 


  • May include surgery or suture ligation

 polydactyly, ellis-van creveld

Polydactyly. There is an extra digit, fully formed, on the ulnar side of the hand in this patient with Ellis-van Creveld Syndrome.

McCarroll HR (2000). "Hand anomalies.". J Hand Surg [Am] 25 (6): 1007–37


Frantz CH, O’Rahilly R (1961). "Congenital skeletal limb deficiencies". J Bone Joint Surg Am 43: 1202–24