Assessing the Wrightington Classification System for elbow fracture-dislocations : an external reliability study.

Aims: Complex elbow fracture-dislocations often result in suboptimal outcomes and necessitate a thorough understanding of injury patterns to guide effective management and reduce adverse sequelae. The Wrightington Classification System (WCS) offers a comprehensive approach and considers both bony and soft-tissue disruption, providing clearer guidance for treatment. This is the first external study to assess the reliability of the WCS for elbow fracture-dislocations.

Methods: A blinded study of patients with elbow fracture-dislocations at a single institution between December 2014 and December 2022 was conducted. Five assessors with a range of experience, including orthopaedic surgeons and radiologists, independently classified injuries using the WCS across three image methods: plain radiograph, 2D CT, and 2D and 3D CT reconstruction images, on two occasions with an eight-week interval. Interobserver and intraobserver reliability were evaluated using kappa statistics and the Landis and Koch criteria.

Results: A total of 73 patients were included in the study. Interobserver reliability was moderate, with mean kappa values of 0.518 (95% CI 0.499 to 0.537), 0.557 (95% CI 0.537 to 0.577), and 0.582 (95% CI 0.562 to 0.601), for radiographs, 2D CT, and 2D and 3D CT reconstructions, respectively. Intraobserver agreement was substantial (mean kappa 0.695 (SE 0.067), 0.729 (SE 0.071), and 0.777 (SE 0.070) for radiographs, 2D CT, and 3D CT reconstructions, respectively).

Conclusion: The WCS is a reliable and valuable tool for characterizing elbow fracture-dislocations and guiding surgical interventions. This study found moderate reliability in using the WCS, with higher reliability with combined 2D and 3D CT imaging. Further refinement within the WCS in differentiating between coronoid avulsions, basal, anteromedial, and/or anterolateral facet injuries may help improve reliability and reproducibility.