Comparative Study of Bilateral Dual Sacral-Alar-Iliac Screws versus Bilateral Single Sacral-Alar-Iliac Screw for Adult Spine Deformities.

Abstract Objectives This study aimed to evaluate the feasibility of O-arm navigation of bilateral dual sacral-alar-iliac (SAI) screws compared with that of conventional bilateral single SAI and S1 pedicle screws for pelvic anchors in cases of adult spine deformities (ASD). Methods This was a retrospective, comparative study. A total of 39 patients who underwent corrective fusion using SAI screws from T10 to the pelvis were included in this study. Patients were divided into two groups according to the number of SAI screws placed during ASD surgery: those with single SAI screws (group S, 17 cases) and those with dual SAI screws (group D, 22 cases). The incidence of rod breakage, proximal junctional kyphosis, screw loosening, reoperation, and global alignment in each group was estimated. Postoperative patient-reported outcome measurement was performed using the Oswestry Disability Index, Japanese Orthopedic Association Back Pain Evaluation Questionnaire, and the visual analog scale. Results The incidence of SAI screw loosening was significantly lower in group D than in group S (23% vs. 65%, respectively; p = 0.011). The rod breakage incidence was 0% and 12% in groups D and S, respectively (p = 0.17). There were no significant differences in the postoperative global alignment and clinical outcomes between the two groups. Conclusion Dual SAI screws were associated with a significantly reduced incidence of screw loosening as compared with that with single SAI screws. The bilateral dual SAI screw technique for pelvic anchors is feasible for the treatment of patients with ASD.