The AO Spine Upper Cervical Injury Score (UCIS): Development of a Consensus-Based Scoring System Based on Perceived Injury Severity Scores

Study DesignCross-sectional Survey-Based Study.ObjectivesExisting classification systems for upper cervical spine trauma lack structured guidance for clinical decision-making. While the AO Spine Upper Cervical Injury Classification (UCIC) provides a comprehensive framework, it lacks an accompanying injury score. This study aimed to develop the AO Spine Upper Cervical Injury Score (UCIS) based on global perceived injury severity scores (ISS).MethodsData from a global survey of 159 surgeons were analyzed. Surgeons assigned a perceived ISS (0-100) to each UCIC variable relative to the need for surgical stabilization. Median ISS values for injury morphology, neurologic status, and modifiers were translated into an integer-based scoring system.ResultsStable Type A injuries were assigned 1 point, while unstable ligamentous and translational injuries received higher scores (eg, Type IIB = 5 points; Type IC = 7 points). For neurologic status, N0 received 0 points, N1/N2 received 1 point, and N3/4 were consolidated to 6 points. Unexamined patients (NX) were allocated 3 points. Modifiers M1 (nonunion risk) and M3 (comorbidities) were assigned 3 points (ISS 60.0), while M2 (instability received 4 points (ISS 75.0).ConclusionThe AO Spine UCIS is a simplified scoring system that translates global consensus on injury severity to a clinically applicable score. It was built upon a foundational survey demonstrating minimal geographic or experiential variability in severity ratings. The UCIS serves as a clinically relevant tool to complement the validated AO Spine UCIC system and provides the necessary framework for the future development of a treatment algorithm for upper cervical spine injuries.