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

Abstract

Study design: Retrospective cohort study at a tertiary trauma center.

Purpose: 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.

Overview of literature: 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.

Methods: 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.

Results: 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.

Conclusions: 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.