COMPUTERIZED TOMOGRAPHY PARAMETERS OF SPINAL CANAL DIMENSIONS IN PARAPLEGIC AND NON-PARAPLEGIC PATIENTS WITH BURST FRACTURE OF THE FIRST LUMBAR VERTEBRA

Background – In the cervical spine there is a relation between spinal canal dimension and the occurrence of neurologic sequelae after trauma, while at the first lumbar vertebra (L 1) this relation has not been conclusively established. In this study we aimed to investigate such an association. Methods – One-hundred patients with L1 burst fracture, admitted to the Department of Neurosurgery, Kerman University of Medical Sciences between 1995 and 2002 (50 paraplegic and 50 without neurologic deficit) were included in the study. Using computerized tomography (CT) scanning, the ratio of sagittal-to-transverse diameter (S/T ratio) and the cross-sectional area (CSA) of the spinal canal at L1 were measured. Statistical analysis, comparing those patients with neurologic deficit to those without, was performed using a t-test, and a simple linear regression model between S/T ratio and CSA was designed. Results – In paraplegic patients, the S/T ratio was 39.08 ± 6.63 (mean ± SD) and CSA was 309.92 ± 22.48 mm2. In neurologically intact patients, S/T ratio was 48.46 ± 6.43 and CSA was 349.34 ± 22.35 mm2. The S/T diameter ratio and CSA were significantly smaller in paraplegic patients than in those without a neurologic deficit (p < 0.05 for both). However, a simple Pearson bivariate correlation showed that the relation between S/T ratio and CSA of the spinal canal was not significant (p > 0.05). Conclusion – CT parameters of spinal canal dimensions correlated with severe neurologic deficit (paraplegia) in L1 burst fracture with retropulsed bone fragments in the spinal canal, but these parameters did not significantly relate to each other.