AO Classification

The AO group has developed a comprehensive classification of fractures. The classification is arranged in order of increasing severity according to the complexities of the fracture, difficulty of treatment and worsening prognosis.

More detailed information about the classification can be obtained from AO Foundation

• AO Classification – General Principles
• 11 – Proximal Humerus
• 12 – Humeral Diaphysis
• 13 – Distal Humerus
• 21 – Radius/Ulna Proximal
• 22 – Radius/Ulna Diaphysis
• 23 – Radius/Ulna Distal
• 31 – Femur Proximal
• 32 – Femur Diaphysis
• 33 – Femur Distal
• 41 – Tibia/Fibula Proximal
• 42 – Tibia/Fibula Diaphysis
• 43 – Tibia/Fibula Distal
• 43 – Tibia/Fibula Malleoli