Polydactyly

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
  

Associations

• 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 

Treatment

• May include surgery or suture ligation

 
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