OBJECT The aim of this study was to determine if the ability of a surgeon to correctly classify A3 (burst fractures with a single endplate involved) and A4 (burst fractures with both endplates involved) fractures is affected by either the region or the experience of the surgeon. METHODS A survey was sent to 100 AOSpine members from all 6 AO regions of the world (North America, South America, Europe, Africa, Asia, and the Middle East) who had no prior knowledge of the new AOSpine Thoracolumbar Spine Injury Classification System. Respondents were asked to classify 25 cases, including 6 thoracolumbar burst fractures (A3 or A4). This study focuses on the effect of region and experience on surgeons' ability to properly classify these 2 controversial fracture variants. RESULTS All 100 surveyed surgeons completed the survey, and no significant regional (p > 0.50) or experiential (p > 0.21) variability in the ability to correctly classify burst fractures was identified; however, surgeons from all regions and with all levels of experience were more likely to correctly classify A3 fractures than A4 fractures (p < 0.01). Further analysis demonstrated that no region predisposed surgeons to increasing their assessment of severity of burst fractures. CONCLUSIONS A3 and A4 fractures are the most difficult 2 fractures to correctly classify, but this is not affected by the region or experience of the surgeon; therefore, regional variations in the treatment of thoracolumbar burst fractures (A3 and A4) is not due to differing radiographic interpretation of the fractures.
Keywords: A3 fracture; A4 fracture; AOSpine Thoracolumbar Spine Injury Classification System; PLC = posterior ligamentous complex; SIS = Spine Injury Score; TLICS = Thoracolumbar Injury Classification and Severity Score; regional radiographic interpretation; regional treatment variation; thoracolumbar burst fractures; trauma.