Unconventional fixation of thoracolumbar fractures using round hole bone plates and transpedicular screws

Abstract

Background: In an attempt to contain the high cost of commercially available pedicle screw systems, several authors have used unconventional alternatives such as locally made plates or dynamic compression plates (DCP) along with cancellous screws for transpedicular fixation of the thoracolumbar spine. These plates, however, allow for a wide range of motion at the plate-screw interphase and the construct does not provide stability in the sagittal plane. Round hole bone plates, on the other hand, allow much less mobility at the plate-screw interphase and the final construct offers better stability in the sagittal plane. Our objective was to determine the clinical, radiologic, and functional status of patients who underwent posterior fracture fixation using round hole bone plates and cancellous screws, and evaluate the construct's ability to maintain reduction of the fracture.

Patients and methods: This was a prospective follow-up of patients with fractures around the thoracolumbar junction fixed using round hole bone plates and cancellous transpedicular screws. Round hole bone plates along with 6.5 mm transpedicular cancellous screws were used for posterior spinal instrumentation in neurologically intact patients with isolated unstable fractures of the last thoracic or first lumbar vertebra.

Results: Seventeen patients were included in this study. Their mean follow-up was 10 months (range 5 to 12). All had evidence of fusion at a mean of 5 months (range 4 to 7). No patient had breakage or loosening of the screws and none had breakage of the plate. The mean kyphosis angle at the fracture site was 34 degrees preoperatively, --4 degrees in the immediate postoperative period, and 3 degrees on final follow-up radiographs. The percentage loss of anterior vertebral body height was 51% preoperatively, 15% in the immediate postoperative period, and 16% on final follow-up radiographs.

Conclusion: The use of round hole bone plates along with 6.5 mm cancellous screws inserted into the pedicles provides an angle-stable construct that allows for better stability in the sagittal plane. It is effective in the surgical treatment of unstable fractures around the thoracolumbar junction. Because of their low cost and ease of insertion, round hole bone plates are an excellent choice for short arthrodesis and instrumentation of such fractures.