Posterior longitudinal ligament status in cervical spine bilateral facet dislocations.
OBJECTIVE
It is generally accepted that cervical spine bilateral facet dislocation results in complete disruption of the posterior longitudinal ligament. The goal of this study was to evaluate the integrity of numerous spine-stabilizing structures by MRI, and to determine if any associations between injury patterns exist with respect to the posterior longitudinal ligament status.


METHODS
Retrospective case series.


METHODS
A retrospective review was performed of 30 cervical spine injury subjects with bilateral facet dislocation. Assessment of 1.5T MRI images was carried out for: intervertebral disc disruption, facet fracture, and ligamentous disruption. Statistical analyses were performed to evaluate for associations between various injury patterns and posterior longitudinal ligament status.


RESULTS
The frequency of MRI abnormalities was: anterior longitudinal ligament disruption (26.7%), disc herniation or disruption (90%), posterior longitudinal ligament disruption (40%), facet fracture (63.3%) and disruption of the posterior column ligament complex (97%). There were no significant associations between injury to the posterior longitudinal ligament and other structures. Compared to surgical reports, MRI was accurate for determining the status for 24 of 26 ligaments (three of three anterior longitudinal ligament, seven of nine posterior longitudinal ligament, and 14 of 14 posterior column ligament complex) but generated false negatives in two instances (in both MRI showed an intact posterior longitudinal ligament that was torn at surgery).


CONCLUSIONS
In contradistinction to the existing concept, the posterior longitudinal ligament can remain intact in a substantial proportion of hyperflexion injuries that produce bilateral cervical facet dislocation. Posterior longitudinal ligament integrity is not associated with any other injury pattern related to the anterior longitudinal ligament, intervertebral disc or facet fracture.
Harvard Medical School, Department of Radiology, Brigham and Women's Hospital, 75 Francis St., Boston, MA 02115, USA. jcarrino@partners.org
John A
JA
Carrino
Geoffrey L
GL
Manton
William B
WB
Morrison
Alex R
AR
Vaccaro
Mark E
ME
Schweitzer
Adam E
AE
Flanders
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000293:injuries* / Q000473:pathology; D005260:Female; D006801:Humans; D004204:Joint Dislocations / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology; D017846:Longitudinal Ligaments / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019838:Neck Injuries / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed