Comparison of curative effect of unilateral and bilateral vertebral pedicle screw instrumentation for treatment of thoracolumbar burst fractures

Abstract

Objective To compare the efficacy of unilateral and bilateral pedicle screw instrumentation for treatment of thoracolumbar burst fractures. Methods A retrospective case-control analysis was made on 50 patients with thoracolumbar burst fractures free from neurological deficit admitted between January 2008 and October 2013. There were 37 males and 13 females, aged from 24 to 51 years (mean, 36 years). Injuries were caused by high falls in 23 patients, traffic accidents in 18 and crashing accidents in 9. Distribution of the injured segment was T11 in 6 patients, T12 in 16, L1 in 20 and L2 in 8. Based on the surgical procedures, the patients were assigned to unilateral pedicle screw fixation group (n=35) and bilateral pedicle screw fixation group (n=15). Operation time, intraoperative blood loss and hospital length of stay were recorded. Visual analogue scale (VAS), Oswestry disability index (ODI), kyphotic angle and anterior vertebral height were evaluated before surgery, after surgery and at 1-year follow-up. Results No screw lessening, screw breakage or infection occurred at 1-year follow-up. Unilateral and lateral pedicle screw instrumentation groups revealed no significant differences in operation time [(81.4± 10.0)min vs. (83.3±13.6)min], intraoperative blood loss [(194.0±65.4)ml vs. (212.0±61.9)ml] and hospital length of stay [(10.3±1.3)d vs. (9.9±1.5)d] (P>0.05). After operation, VAS and ODI in unilateral pedicle screw instrumentation group (3 points, 73.9) showed no significance from these in lateral pedicle screw instrumentation group (2 points, 72.1) (P>0.05). VAS was within 1 point and ODI was within 20 at 1-year follow-up, showing no significant differences between the two groups (P>0.05). After operation, correction of kyphotic Cobb angle and restoration of anterior vertebral body height in unilateral pedicle screw instrumentation group (8°, 26.7%) showed no significance from these in lateral pedicle screw instrumentation group (11°, 32.1%) (P>0.05). Loss of local kyphotic Cobb angle and anterior vertebral body height in unilateral pedicle screw instrumentation group (2°, 3%) showed no significance from these in lateral pedicle screw instrumentation group (1°, 2%) at 1-year follow-up (P>0.05). Conclusion Both methods have comparable efficacy in restoring vertebral height and improving spinal kyphosis for treatment of thoracolumbar burst fractures. Key words: Spinal fractures; Fracture fixation, internal; Pedicle screws