The subgroups represent a variation within the group and the one illustrated is indicated with red in the text.
A1 Simple fracture, of the ulna, radius
intact
.1 oblique
.2 transverse
.3 with dislocation of the radial head
(Monteggia)
A2 Simple fracture, of the
radius, ulna intact
.1 oblique
.2 transverse
.3 with dislocation of the distal
radio-ulnar joint (Galeazzi)
A3 Simple fracture of both bones
.1 radius, proximal zone
.2 radius, middle zone
.3 radius, distal zone
B1 Wedge fracture, of the ulna,
radius intact
.1 intact wedge
.2 fragmented wedge
.3 with dislocation of the radial head (Monteggia)
B2 Wedge fracture, of the radius,
ulna intact
.1 intact wedge
.2 fragmented wedge
.3 with dislocation of the distal radio-ulnar joint (Galeazzi)
B3 Wedge fracture, of the one bone,
simple or wedge fracture of the other
.1 ulna wedge and simple fracture of the radius
.2 radial wedge and simple fracture of the ulna
.3 ulnar and radial wedges
C1 Complex fracture, of the ulna
.1 bifocal, radius intact
.2 bifocal, radius fractured
.3 irregular
C2 Complex fracture, of the radius
.1 bifocal, ulna intact
.2 bifocal, ulna fractured
.3 irregular
C3 Complex fracture, of both bones
.1 bifocal
.2 bifocal of the one, irregular of the other
.3 irregular