AO Distal Radius Fracture Classification: Global Perspective on Observer Agreement

Area of Science:

• Orthopedic Surgery
• Radiology
• Medical Imaging

Background:

• Fracture classification systems are crucial for treatment planning and outcome assessment.
• The AO classification system is widely used for distal radius fractures (DRFs).
• Interobserver reliability of classification systems can impact clinical decision-making.

Purpose of the Study:

• To assess the interobserver reliability of the AO classification system for DRFs among a large international group of surgeons.
• To evaluate factors influencing inter- and intraobserver agreement, including geographical location, training level, and subspecialty.

Main Methods:

• A randomized set of 96 DRF radiographic and CT images were classified by an international group of surgeons using a web-based portal.
• Participants classified the fractures on two separate occasions to assess intraobserver reproducibility.
• Data were analyzed to determine interobserver reliability and agreement based on various factors.

Main Results:

• Interobserver reliability was substantial for AO type A fractures, fair for type B, and moderate for type C.
• No significant differences in agreement were found based on geographical location, training level, or subspecialty, with a minor exception for type B fractures between Indian and Australian participants.
• Intra-rater reproducibility was substantial for fracture types and fair for fracture groups.

Conclusions:

• The AO classification system demonstrates variable interobserver reliability for DRFs, particularly for complex fracture types.
• Using large international groups enhances the definition of reliability and reproducibility for classification systems.
• These findings can inform the optimal utilization of fracture classification systems in orthopedic practice.