Classification of the AO-ASIF Group for Fractures of the Humerus Diaphysis

Simple Fracture

Type of Fracture

Fracture Code

simple spiral fracture

proximal zone

A1.1

middle zone

A1.2

distal zone

A1.3

simple oblique fracture (>= 30°)

proximal zone

A2.1

middle zone

A2.2

distal zone

A2.3

simple transverse fracture (< 30°)

proximal zone

A3.1

middle zone

A3.2

distal zone

A3.3

Wedge Fracture

Type of Fracture

Fracture Code

spiral wedge fracture

proximal zone

B1.1

middle zone

B1.2

distal zone

B1.3

bending wedge fracture

proximal zone

B2.1

middle zone

B2.2

distal zone

B2.3

fragmented wedge fracture

proximal zone

B3.1

middle zone

B3.2

distal zone

B3.3

Complex Fracture

Type of Fracture

Fracture Code

complex spiral fracture

with 2 intermediate fragments

C1.1

with 3 intermediate fragments

C1.2

with >= 4 intermediate fragments

C1.3

complex segmental fracture

with 1 intermediate segmental fragment

C2.1

with 1 intermediate segmental fragment and additional wedge fragment(s)

C2.2

with 2 intermediate segmental fragments

C2.3

complex irregular fracture

with 2 or 3 intermediate fragments

C3.1

with limited shattering (< 4 cm)

C3.2

with extensive shattering (>= 4 cm)

C3.3