Wassel (and Flatt) reported a classification for polydactyly of the thumb (radial or preaxial polydactyly. The authors are from the University of Iowa.
Outcome: 7 categories (from I to VII)
Parameters:
(1) bifid bone (distal phalanx, proximal phalanx, metacarpal)
(2) number of distal phalanges
(3) number of proximal phalanges
(4) number of first metacarpals
(5) presence of a third phalanx
Finding
I
II
III
IV
V
VI
VII
bifid
DP
no
PP
no
MC
no
no
number distal phalanges
1
2
2
2
2
2
2
number proximal phalanges
1
1
1
2
2
2
2
number metacarpals
1
1
1
1
1
2
2
third phalanx?
N
N
N
N
N
N
Y
Category
Descriptor
I
bifid distal phalanx
II
duplicated distal phalanx
III
bifid proximal phalanx
IV
duplicated proximal phalanx
V
bifid metacarpal
VI
duplicated metacarpal
VII
triphalangism
To read more or access our algorithms and calculators, please log in or register.
