Imaging findings of flexion type of hangman's fracture; an attempt for a more objective evaluation with newly introduced scoring system

Objective:To identify the flexion type of hangman's fracture on imaging studies.Methods:38 cases of hangman's fracture were retrospectively studied and categorized into flexion and non-flexion groups. Plain radiograph, CT and MRI of these patients were evaluated; 13 radiological parameters that might define flexion injuries were measured. The data were statistically analyzed to identify good criteria and to rank them according to their importance in predicting flexion.Results:Seven radiological criteria that have the highest correlation with flexion injury were identified. These are C2–3 lower end-plate angle, C2–3 posterior body angle, interspinous angle, disc disruption (MRI), widening of interspinous distance, disruption of the posterior ligamentous complex (MRI) and angle at the fracture site. Scoring 1 point for each positive criterion, a total score of 4 predicts flexion injury with 100% sensitivity and 96.9% specificity. Score of 5 has 83.3% sensitivity and 100% specificity.Conclusion:Flexion hangm...