Preaxial polydactyly refers to polydactyly where the additional digit is towards the first digit of the hand (radial side) or foot (medially).
Radial polydactyly can be classified using the Wassel classification system.
Epidemiology
Preaxial polydactyly is less common than postaxial polydactyly, with an estimated incidence of 1 in 7000.
Associations
Preaxial polydactyly may be associated with: