Sacropelvic Fixation With S2 Alar Iliac Screws May Prevent Sacroiliac Joint Pain After Multisegment Spinal Fusion

Study Design. A retrospective study. Objective. To examine the postoperative incidence of sacroiliac joint pain (SIJP) at the lower fusion level following multisegment fusion. Summary of Background Data. Recently, multisegment fusion is being increasingly performed. While proximal junctional kyphosis (PJK) commonly develops following multisegment fusion, SIJP also commonly occurs following this surgery. In surgery for adult spinal deformity, fixation is often extended to the pelvis to include the sacroiliac joint. Therefore, the question of whether SIJP occurs in such cases is interesting. Here, we examined postoperative incidence of SIJP at the lower fusion level, including the incidence of PJK, and postoperative lumbopelvic alignment. Methods. Participants included 77 patients who underwent corrective fusion (>= 3 segments). Patients were divided into three groups based on the lower fixation end: L5 (L5), S (sacrum), and P (pelvis). In the P group, an S2 alar iliac screw was used. Postoperative incidence of SIJP and PJK in each group was examined along with lumbopelvic parameters. Results. SIJP incidence was 16.7%, 26.1%, and 4.2% in the L5, S, and P groups, respectively, indicating the highest value in the S group and a significantly lower value in the P group. PJK incidence was 23.3%, 30.4%, and 29.2% in the L5, P, and S groups, respectively, with no significant differences. Regarding postoperative lumbopelvic parameters, there was no significant difference between the groups; however, lumbar lordosis tended to be better in the P group. Conclusion. SIJP incidence was extremely high with fixation to the sacrum, and in the group with fixation to the pelvis, there was hardly any SIJP. Sacropelvic fixation using S2 alar iliac screws could prevent SIJP onset following multisegment fusion.