The impact of the lateral decubitus position in the perioperative period on posterior fixation for thoracolumbar fracture with ankylosing spinal disorder.

Abstract

Patients with ankylosing spinal disorders (ASDs), such as ankylosing spondylitis and diffuse idiopathic skeletal hyperostosis, often have rigid kyphosis of the spine. The fracture site is sometimes unintentionally displaced when surgery is conducted with the patient prone. To prevent this incident, the authors adopted the lateral decubitus position for patients intraoperatively for this pathology. The aim of this study was to retrospectively assess the impact of the lateral decubitus position in the perioperative period on posterior fixation for thoracolumbar fractures with ASD. Thirty-seven consecutive patients who underwent posterior instrumentation for thoracolumbar fracture with ASD at the authors' institute were divided into 15 lateral decubitus positions (group L) and 22 prone positions (group P). Surgical time, estimated blood loss (EBL), number of levels fused, perioperative complications, length of stay (LOS), ratio of fracture voids, and ratio of anterior wall height were investigated. The ratio of fracture void and the ratio of anterior wall height were the radiological assessments showing a degree of reduction in vertebral fracture on CT. Age, sex, BMI, fracture level, and LOS were similar between the groups. Levels fused and EBL were significantly shorter and less in group L (p < 0.001 and p = 0.04), but there was no significant difference in surgical time. The complication rate was similar, but 1 death within 90 days after surgery was found in group P. The ratio of fracture voids was 85.4% ± 12.8% for group L and 117.5% ± 37.3% for group P. A significantly larger number of patients with a fracture void ratio of 100% or less was found in group L (86.7% vs 36.4%, p = 0.002). The ratio of anterior wall height was 107.5% ± 12.3% for group L and 116.9% ± 18.8% for group P. A significantly larger number of patients with the anterior wall height ratio of 100% or less was also found in group L (60.0% vs 27.3%, p = 0.046). The results of this study suggest that the lateral decubitus position can be expected to have an effect on closing or maintaining the fracture void or a preventive effect of intraoperative unintentional extension displacement of the fractured site, which is often seen in the prone position during surgery for thoracolumbar fractures involving ASD.