The impact of stenosis and translation on spinal cord injuries in traumatic cervical facet dislocations.

BACKGROUND CONTEXT

Although facet dislocations account for only 6% of cervical trauma, the consequences are often devastating. Cervical facet dislocations are associated with a disproportionate amount of spinal cord injuries; however, neurologic examination of patients is often difficult, as patients commonly present with reduced levels of consciousness. There are limited studies that have investigated the impact of spinal canal diameter and translation on neurologic injury following facet dislocations.

PURPOSE

Review a consecutive series of patients with facet dislocations to assess the impact of sagittal diameter and translation on Spinal Cord Injury (SCI).

STUDY DESIGN

Retrospective review at a level I trauma center identified 97 patients with facet dislocations.

METHODS

Between 2004 and 2014, a retrospective review at a level I trauma center identified patients with traumatic facet dislocation. Demographic data, neurologic exams, and radiographic findings were reviewed. We assessed sagittal diameter at the injury level, as well as above and below, and translation. This study has no funding source and its authors have no potential conflicts of interest-associated biases.

RESULTS

Ninety-seven patients presented with facet dislocations. Fifty-nine (61%) presented with a SCI. Those with ASIA A averaged 8.0 mm of injury level canal diameter, and ASIA E averaged 12.6 mm (p < .001). Additionally, those with ASIA A averaged 8.0 mm of translation, and ASIA E averaged 4.2 mm (p < 0.001). Two groups were created based on their general motor function. Those with ASIA A-C averaged 8.4 mm of injury level canal diameter, and ASIA D-E averaged 12.3 mm (p < .001). Those with ASIA A-C averaged 7.8 mm of translation, and ASIA D-E averaged 4.4 mm (p < .001). Receiver operating characteristic (ROC) curves demonstrated that translation was a good predictor of ASIA A-C and canal diameter was an almost perfect predictor of ASIA D-E.

CONCLUSIONS

Our data indicate that patients with greater translation and/or a smaller canal diameter at the injury level have a higher rate of SCI. Adjacent canal diameter did not correlate with neurologic injury.