Efficiency of Ligamentotaxis Using PLL for Thoracic and Lumbar Burst Fractures in the Load-sharing Classification

Abstract

The use of pedicle screws for short-segment implants has been known to be dangerous in patients who score a 7 or higher on McCormack's classification. The efficiency of ligamentotaxis of the posterior longitudinal ligament (PLL) and short-segment implants and fusion in relation to McCormack's classification has not been proven. The purpose of this study was to compare the clinical and radiological results of indirect decompression using PLL ligamentotaxis between patients with a high- (score of 7 or higher) or low-grade (score of 6 or less) fracture. Eighteen patients (19 levels) in the low-grade fracture group were compared with 23 patients (27 levels) in the high-grade fracture group. Clinical outcomes were measured using the Oswestry Disability Index (ODI) and visual analog scale (VAS) scores; radiologic measures were determined using the spinal canal area and mean sagittal diameter; and the complications were evaluated and compared. A significant improvement in each groups was found in the mean pre- and postoperative spinal canal area, mean sagittal diameter, Cobb's angle, and anterior vertebral height compression rate. A significant difference was found between the 2 groups in the mean pre- and postoperative spinal canal area, mean sagittal diameter, and anterior vertebral height compression rate. Moreover, the VAS and ODI scores continued to significantly improve at the last follow-up in each group. No difference was found in the prevalence of complications. Despite a high score, no significant difference was found in the clinical and radiological results and the complications. Therefore, indirect decompression using PLL ligamentotaxis was found to be a useful technique for patients who recieve a high McCormack's classification score.