Predictors of failed closed reduction in subaxial cervical dislocations with interlocked facets: a retrospective cohort study.

Abstract

Retrospective cohort study at a tertiary trauma center. To identify morphological predictors of failed closed reduction in subaxial cervical dislocation with interlocked facets, focusing on a dichotomized compression-extension (CE) versus non-CE classification, and to assess the association of vertebral artery injury (VAI) with reducibility. Closed cranial traction is rapid and minimally invasive, yet certain morphologies resist reduction. Prior studies proposed various predictors, but few directly compared CE with non-CE injuries or evaluated VAI. We analyzed 111 dislocation events in 110 patients treated from 2017 to 2025. All underwent standardized cranial traction. Predictors of success included CE versus non-CE morphology, facet fracture, bilateral dislocation, age, level, American Spinal Injury Association Impairment Scale (ASIA) grade, and time-to-reduction (≤6 hours, 6-12 hours, 12-24 hours, >24 hours). The primary outcome was failure of a closed reduction requiring an open reduction. Logistic regression analyses were performed. VAI was examined as an exploratory factor. Closed reduction failed in 34 events (30.6%). CE morphology (p<0.001) and facet fracture (p=0.001) were independently associated with failure. Younger age and C7 dislocation were significant only in univariate analyses. Bilateral dislocation, ASIA grade, and time-to-reduction were not predictive. VAI was slightly more frequent in the success group (p=0.069) but showed no independent association. A simplified CE-non-CE classification and facet fracture strongly predict irreducibility. VAI is not independently associated with success. Early computed tomography-based identification of CE and facet fracture should guide timely planning for open reduction and stabilization.