Background: Systems for classifying cervical spine injury most
commonly use mechanistic or morphologic terms and do not quantify the degree
of stability. Along with neurologic function, stability is a major determinant
of treatment and prognosis. The goal of our study was to investigate the
reliability of a method of quantifying the stability of subaxial (C3-C7)
cervical spine injuries.
Methods: A quantitative system was developed in which an analog
score of 0 to 5 points is assigned, on the basis of fracture displacement and
severity of ligamentous injury, to each of four spinal columns (anterior,
posterior, right pillar, and left pillar). The total possible score thus
ranges from 0 to 20 points. Fifteen examiners assigned scores after reviewing
the plain radiographs and computed tomography images of thirty-four
consecutive patients with cervical spine injuries. The scores were then
evaluated for interobserver and intraobserver reliability with use of
intraclass correlation coefficients.
Results: The mean intraobserver and interobserver intraclass
correlation coefficients for the fifteen reviewers were 0.977 and 0.883,
respectively. Association between the scores and clinical data was also
excellent, as all patients who had a score of =7 points had surgery.
Similarly, eleven of the fourteen patients with a score of =7 points had a
neurologic deficit compared with only three of the twenty with a score of
Conclusions: The Cervical Spine Injury Severity Score had excellent
intraobserver and interobserver reliability. We believe that quantifying
stability on the basis of fracture morphology will allow surgeons to better
characterize these injuries and ultimately lead to the development of
treatment algorithms that can be tested in clinical trials.