Abstract

Resumen

Introduction

Materials and methods

Procedure

Statistics

Results

Discussion

Conclusion

Level of evidence

References

Abstract

Introduction
The correction of thoracic and lumbar spine fractures with a short instrumentation using Schanz screws, is an effective method for stabilization and sagittal balance restoration.

Materials and methods
Bidirectional observational study, included patients undergoing arthrodesis with Schanz screws to manage thoracic and lumbar fractures, the general characteristics, type, and location of the fracture, besides the gain in height of the vertebral body and segmental angle were analyzed before and after surgery. Clinical and imaging control was performed postoperatively and 1 month after this. p-value < .05 was statistically significant.

Results
Of 35 patients undergoing arthrodesis, 13 were excluded due to the absence of images and follow-up. There was a higher proportion of men, the main location of the fracture and AO spine classification was in T12 and type A4/B1 respectively, there was no intraoperative complication, no transfusion was required, and a short hospital stay. A mild complication was presented in the follow-up. The average pre and postoperative change was 12 degrees in the Cobb angle and 5.2 mm vertebral body height in the fractured vertebra, these changes were statistically significant.

Conclusion
Thoracolumbar and lumbar spine fracture correction with short segment fixation using Schanz screws, is an effective, safe and fast, showing significantly vertebral height gain and segmental angle correction, as a consequence, a correction of the balance and alignment of the spine.

Materials and methods

A bidirectional case series study (retrospective and prospective) was performed, of patients who had undergone surgery for arthrodesis with Schanz screws for the management of traumatic thoracic and lumbar fractures. Patients were excluded from the study if data were lacking from their medical records, or there were no control and/or follow-up postoperative images. Sociodemographic information was collected, together with location and type of fracture in accordance with the AO Spine classification,4 pre and postoperative height of the fracture vertebral body and the Cobb angle (also called segmentary angle), and intra and postoperative complications. Regarding clinical and imaging follow-up, this was performed on the first postoperative day and month (Fig. 1). Routine radiography and computerized axial tomography (CAT) was taken for all patients of the thoracic and lumbar spine at the time of the trauma. Given the availability of hospital resources, magnetic resonance of the thoracic and lumbar sacral spine was made of selected patients who were waiting for this, to determine lesion of the posterior ligament complex.

Procedure

The patient was placed in prone position, with upper members extended, with pressure areas protected by rolls. Fluoroscopy marked the mid line and the pedicles of the vertebrae above and below the surgical fracture line. Subperiosteal dissection followed to expose posterior elements of the spine. Biplane fluoroscopy was used to place the Schanz screws bilaterally. The diameter of the screws had been previously measured in imaging. The screws were always to be placed proximal in bloodflow direction for better leverage. Reduction and ligamentotaxis manoeuvres followed with fixation of patellas and rods. Sharp round bur was used for scarification of bone surface and heterologous bone graft placement. Haemostasis was confirmed, layered closure and 1/8 epifascial hemovac drainage was left as required. In some cases, where bone fragments may be found inside the canal, laminectomy and impaction is performed on them (Fig. 2).