1624. Minimally Invasive Sacroiliac Joint Fusion with Cylindrical Threaded Implants Using Intraoperative Stereotactic Navigation

Authors: Sharad Rajpal, MD, FAANS ; Sigita Burneikiene, MD (Boulder, CO)

Introduction: Over the last decade there has been significant progress in hardware and surgical techniques for sacroiliac joint (SIJ) fusion surgeries, facilitating safer and more efficacious procedures for patients. Triangular-shaped implants for SIJ fusions are the most studied devices of its kind and have demonstrated good short- and long-term clinical outcomes. There are very limited reports available, however, on cylindrical threaded implants. Due to the biomechanical differences in the implants and the surgical techniques required for their placement, previously reported results may not applicable to cylindrical threaded implants. The purpose of this study was to report our preliminary clinical experience with minimally invasive (MI) SIJ fusion using intraoperative stereotactic navigation and the Rialto SI Fusion System. Methods: We retrospectively reviewed a total of 26 patients who underwent SIJ fusions between May of 2015 and February of 2018 performed by a single surgeon. Results: The mean total satisfaction score was 85.5 ± 23.1%. A statistically significant reduction (p=0.001) in low back pain scores was noted from an average baseline score of 6.6 ± 2.2 to 3.5 ± 3.2 postoperatively. Leg pain scores decreased from 4.7 ± 3.8 to 1.9 ± 2.6 (p=0.012). The mean surgery time was 52.7 ± 13.4 min. It took significantly longer (p=0.0065) to perform the initial 13 cases (59.9 ± 15.2 min) compared with the subsequent cases (46.0 ± 6.9 min). The EBL was minimal - 10.4 ± 5.0 mL. Conclusion: Minimally invasive SI joint fusion using cylindrical threaded implants can be safely performed with minimal morbidity and good clinical outcomes.