The Changes in the Dimensions of Neural Foramen After Anterior Interbody Fusion in the Spondylolisthesis

Abstract

Study Design: A prospective radiological assessment was performed using computerized tomography measurements. Objectives: The aim of this study was to assess the changes in the dimensions of the neural foramen after anterior interbody fusion with posterior fixation in spondylolisthesis. Summary of Literature Review: Anterior lumbar interbody fusion distracts the height and width of the neural foramen. Materials and Methods: Anterior interboody fusion with posterior fixation was performed in twenty-five patients. The sagittal parameters were the height and area of the neural foramen. The fused lumbar segments was imaged in the direct sagittal projections in a CT (SOMATOM Senstaion; SIMENS, Germany) and 1-mm slice thickness before surgery and after solid fusion. Computer digitation was used for the measurements independently by three different observers. Statistical analysis was performed using a Wilcoxon signed test and a paired T-test to determine the correlation between the measurements, and Pearson correlation to determine the level of interobserver and intraobserver agreement. Results: After anterior interbody fusion and posterior fixation, the height and the area of the neural foramen had increased significantly by 15.5±14.0%(p�0.001) and 23.2±17.7%(p�0.001). There was a significant confidence in interobserver (0.9466~0.9996) and intraobserver(0.8896~0.9991) agreement. Conclusions: Anterior interbody fusion significantly increased the changes in the dimensions of the neural foramen. Anterior distraction and decompression with anterior interbody fusion increased the area of the neural foramen This study shows that anterior interbody fusion can be used to decompress the neural foramen in the spondylolisthesis.