classification

Last reviewed 01/2018

Congenital syndactyly may be classified according to the:

  • isolated anomaly or syndromic association
  • tissues fused:
    • simple - soft tissue alone from the proximal end of the digit
    • complex - bone synostosis (metacarpal or phalangeal) and soft tissue
    • acrosyndactyly - complex syndactyly characterised by fusion of the bones distally but not proximally; fenestrations are usually present between the bones proximally and associated with constriction ring syndrome
  • extent of fusion proximal-to-distal:
    • complete - fusion from web space to distal interphalangeal joints; can be associated with synonychia which is a shared or common fingernail
    • incomplete
  • number of digits affected eg single versus multiple
  • unilateral or bilateral
  • site affected:
    • hand
    • foot
    • both