Determinants of Initial Neurological Severity and Clinical Outcomes in Cervical Spine Dislocation Injuries

Abstract

Study design: Retrospective study at a single tertiary care hospital.

Objective: To identify the severe paralysis risk factors at the time of injury in patients with cervical facet dislocations and explore neurological improvement predictors following manual reduction.

Summary of background data: The risk factors associated with severe paralysis at the time of injury remain to be fully elucidated. Furthermore, early reduction is considered essential for improving neurological recovery, other contributing factors remain unclear.

Methods: We retrospectively reviewed 31 patients with distractive flexion injuries treated at a single institution. Radiologic evaluation included measurement of the vertebral body's translation distance, space available for the cord (SAC), and facet dislocation grade on computed tomography or magnetic resonance imaging. Patients were assessed using the American Spinal Injury Association Impairment Scale (AIS) and classified into severe (AIS A-C) and mild (AIS D and E) paralysis groups to identify risk factors for severe paralysis. They were also categorized by reduction timing as early (≤6 h) or delayed (>6 h) groups. Neurological improvement was defined as an AIS grade improvement of at least one level at the final follow-up.

Results: Severe paralysis was significantly associated with bilateral facet dislocation, greater vertebral translation, and smaller SACs. Multivariate analysis revealed that smaller SACs were independent severe paralysis predictors (P=0.0034). Although the early reduction group had more patients with neurological improvement, the difference was not statistically significant. No patients with severe paralysis who underwent delayed reduction showed any improvement. Neurological improvement was more common in female patients (P=0.010), with all females demonstrating improvement regardless of injury severity or imaging findings.

Conclusion: Bilateral facet dislocation, large vertebral translation, and spinal canal stenosis are major severe paralysis risk factors in cervical dislocation injuries. Although early reduction alone did not significantly improve outcomes, delays may hinder recovery in severe cases. Female sex was the only factor significantly associated with neurological improvement.

Evidence level: Level IV.

Keywords: cervical facet dislocation; early reduction; spinal canal stenosis; spinal cord injury.