Fracture Classification (AO)
The Arbeitsgemeinschaft für Osteosynthesefragen (AO) group has developed a comprehensive classification of fractures that is arranged in order of increasing severity. It is an alpha-numeric system:
- The name of the bone e.g. humerus, radius/ulna, femur.
- The location of the fracture e.g. proximal shaft, diaphyseal, malleolar.
- The type of fracture e.g. simple, wedge, complex.
- The fracture group e.g. transverse, oblique, spiral, segmental.
- The fracture subgroup e.g. stability, shortening.
For example, 31A2.1 indicates pertrochanteric fracture of the femur with multiple fragments, one of which is intermediate (3 = femur; 1 = proximal; A = trochanteric; 2 = pertrochanteric, multifragmentary; and 1 = one intermediate fragment). The details are outlined on Trauma.org.
Attempts are being made to amalgamate the AO and the OTA classifications.
