Measurement of spinal canal narrowing, interpedicular widening, and vertebral compression in spinal burst fractures: plain radiographs versus multidetector computed tomography.

OBJECTIVE: To assess the reliability of measurements of spinal canal narrowing, vertebral body compression, and interpedicular widening in burst fractures in radiography compared with multidetector computed tomography (MDCT).
MATERIALS AND METHODS: Patients who had confirmed acute vertebral burst fractures over an interval of 34 months underwent both MDCT and radiography. Measurements of spinal canal narrowing, vertebral body compression, and interpedicular widening from MDCT and radiography were compared.
RESULTS: The 108 patients (30 female, 78 male, aged 16-79 years, mean 39 years) had 121 burst fractures. Eleven patients had multiple fractures, of which seven were not contiguous. Measurements showed a strong positive correlation between radiography and MDCT (Spearman's rank sum test: spinal canal narrowing k = 0.50-0.82, vertebral compression k = 0.55-0.72, and interpedicular widening k = 0.81-0.91, all P < 0.05), except for the cervical spine (k = -0.50 to 0.61, with all P > 0.25) and for interpedicular widening in the thoracic spine (k = 0.35, P = 0.115). The average difference in measurements between the modalities was 3 mm or fewer.
CONCLUSION: Radiography demonstrates interpedicular widening, spinal canal narrowing and vertebral compression with acceptable precision, with the exception of those of the cervical spine.