Comparing the efficacy of short-segment pedicle screw instrumentation with and without intermediate screws for treating unstable thoracolumbar fractures

It is generally acknowledged that short-segment pedicle screw instrumentation is the preferred surgical method for thoracolumbar fractures. However, the use of short-segment instrumentation with or without intermediate screws at the fracture level remains controversial. We retrospectively evaluated 44 patients (28 men, 16 women) with unstable thoracolumbar fractures. The patients were divided into 2 groups according to the surgical method used. In group 1, 24 patients underwent surgery with a posterior approach via shortsegment pedicle screw instrumentation (1 level above and 1 level below the fractured level). In group 2, 20 patients received an additional 2 screws at the fractured vertebrae. Clinical and radiologic parameters were evaluated before surgery and at 1 week, 6 months, and 1 year after surgery. We found no significant difference in the demographic characteristics between the 2 groups. No significant difference was observed in the operative time and intraoperative blood loss between the 2 groups. Clinical outcomes also showed no significant differences between the groups preoperatively or at all follow-up periods. The correction of the Cobb angle (CA) 1 week after surgery was better in group 2, whereas the anterior vertebral body height of the fractured level (AVHF) and compression ratio of the AVHF (AVHFCR) were not significantly different between the 2 groups 1 week after surgery. Moreover, group 2 had better maintenance of restored CA, AVHF, and AVHFCR at the fractured level than did group 1 at 6 months and 1 year postoperatively. In addition, the reduction of mid-sagittal diameter (MSD) of spinal canal 1 week and 1 year after surgery was better in group 2. Besides, bone fragments in the spinal canal have a tendency to be less in group 2 1 week and 1 year after surgery. Reinforcement with intermediate screws for a single thoracolumbar fracture not only enhanced the stability of the internal fixation system, but it was also conducive to the correction of kyphosis and the maintenance of the reduction effects. Furthermore, this method is helpful to restore the spinal canal and reduce the bone fragments in the spinal canal. However, more long-term follow-up studies are needed.