The subgroups represent a variation within the group and the one illustrated is indicated with red in the text.
A1
Simple fracture, spiral
.1 proximal zone
.2 middle zone
.3 distal zone
A2 Simple fracture, oblique(> or = 30°)
.1 proximal zone
.2 middle zone
.3 distal zone
A3 Simple fracture, transverse (< 30°:)
.1 proximal zone
.2 middle zone
.3 distal zone
B1 Wedge fracture, spiral wedge
.1 proximal zone
.2 middle zone
.3 distal zone
B2 Wedge fracture, bending wedge
.1 proximal zone
.2 middle zone
.3 distal zone
B3 Wedge fracture, fragmented wedge
.1 proximal zone
.2 middle zone
.3 distal zone
C1 Complex fracture, spiral
.1 with two intermediate fragments
.2 with three intermediate fragments
.3 with more than three intermediate fragments
C2 Complex fracture, segmental
.1 with one intermediate segmental fragment
.2 with one intermediate segmental and additional wedge fragment(s)
.3 with two intermediate segmental fragments
C3 Complex fracture, irregular
.1 with two or three intermediate fragments
.2 with limited shattering (< 4 cm)
.3 with extensive shattering (> or = 4 cm)