Changes of Spinopelvic Parameter using Iliac Screw In Surgical Correction of Sagittal Imbalance Patients

Abstract

Study Design: A retrospective-based study. Objectives: To evaluate the usefulness of iliac screws in the surgical correction of sagittal imbalance by changes of spinopelvic parameters. Summary of Literature Review: Although reports exist regarding the fusion rates on lumbosacral fusion by iliac screws, no previous studies address the issue of changes of spinopelvic parameters on surgical correction of sagittal imbalance by iliac screws. Materials and Methods: We analyzed a total of 23 patients who were operated on by pedicle subtraction osteotomy and posterior fusion on sagittal imbalance. Patients were divided into two groups: 1) non-iliac screw fixation and; 2) iliac screw fixation. The two groups were compared during the preoperative and postoperative stages, and the last follow-up spinopelvic parameters of two groups. Results: Spinopelvic parameters, except for pelvic incidence, were corrected after surgery; some corrected values of spinopelvic parameters were lost during follow-up. There was a statistically significant difference in the last follow-up period between lumbar lordosis and pelvic tilt. Values of postoperative lumbar lordosis and pelvic tilt was similar to each other; however, during the follow-up period corrected values of spinopelvic parameters of non-iliac screw fixation group were more lost. There were no statistically significant changes in postoperative and last follow-up sacral slope and pelvic incidence. Conclusions: Sagittal imbalance could be corrected by pedicle subtraction osteotomy, and corrected values of lumbar lordosis and pelvic tilt of iliac screw fixation group could be maintained well compared to non-iliac screw fixation. Iliac screw fixation could be useful for maintenance of corrected values of spinopelvic parameters in surgical correction of sagittal imbalance.