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

Simple Fracture

Type of Fracture

Fracture Code

simple fracture, spiral

subtrochanteric zone

A1.1

middle zone

A1.2

distal zone

A1.3

simple fracture, oblique (>= 30°)

subtrochanteric zone

A2.1

middle zone

A2.2

distal zone

A2.3

simple fracture, oblique (<30°)

subtrochanteric zone

A3.1

middle zone

A3.2

distal zone

A3.3

Wedge Fracture

Type of Fracture

Fracture Code

wedge fracture, spiral wedge

subtrochanteric zone

B1.1

middle zone

B1.2

distal zone

B1.3

wedge fracture, bending wedge

subtrochanteric zone

B2.1

middle zone

B2.2

distal zone

B2.3

wedge fracture, fragmented wedge

subtrochanteric zone

B3.1

middle zone

B3.2

distal zone

B3.3

Complex Fracture

Type of Fracture

Fracture Code

complex fracture, spiral

with 2 intermediate fragments

C1.1

with 3 intermediate fragments

C1.2

with > 3 intermediate fragments

C1.3

complex fracture, segmented

with 1 intermediate segmental fragment

C2.1

with 1 intermediate segmental and additional wedge fragment(s)

C2.2

with 2 intermediate segmental fragments

C2.3

complex fracture, irregular

with 2 or 3 segmental fragments

C3.1

with limited shattering (< 5 cm)

C3.2

with extensive shattering (>= 5 cm)

C3.3