Short Term Results of Fixation of Unstable Thoracolumbar Fractures with and without Intermediate Screws: A Comparative Study

Background: Posterior short-segment pedicle screw fixation is widely used for unstable thoracolumbar (TL) fractures. Adding a pedicle screw at the fractured vertebrae could significantly improve the stability and decrease the stress on fixation construct. Objective: Compare the efficacy of short segment pedicle screw fixation with and without intermediate screw in correction of the vertebral body height, local kyphosis and maintenance of the correction in the treatment of unstable thoracolumbar spine fractures. Patients and Methods: This study was a prospective cohort study. 40 patients with unstable thoracolumbar fracture were divided randomly into 2 groups according to the surgical method used. In group B, 20 patients underwent fixation via short-segment pedicle screw instrumentation (1 level above and 1 level below the fractured level). In group A, 20 patients received additional screws at the fractured vertebrae. Results: Both groups had significant correction in Cobb angle, anterior body height and local kyphotic angle. However group A had significantly higher correction achieved in Cobb angle (10.35 ± 6.02), anterior body height (1.15 ± 0.50) and local kyphotic angle (13.30 ± 7.54) than group B (3.45 ± 3.94), (0.40 ± 0.41) and (5.05 ± 4.36) respectively. Nevertheless, the differences in VAS score (p=0.759) and ODI (p=0.934) were not significant. Moreover, group A had a significantly lower loss of correction in Cobb angle (p=0.025) after twelve months of follow up. Conclusion: The construct with intermediate screw was associated with not only better correction but also less correction loss after 12 months. However, this was not reflected on clinical outcome.