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

BACKGROUND: Significant progress in hardware and surgical techniques for sacroiliac joint (SIJ) fusion surgeries has facilitated safer and more efficacious procedures for patients. Triangular-shaped implants for SIJ fusions are the most-studied devices and have demonstrated good short-term and long-term clinical outcomes. Reports on cylindrical threaded implants are very limited. Owing to biomechanical differences in the implants and the surgical techniques required for their placement, previously reported results may not be applicable to cylindrical threaded implants. The aim of this study was to report preliminary clinical experience with minimally invasive SIJ fusion using intraoperative stereotactic navigation and the Rialto SI Fusion System. METHODS: We retrospectively reviewed 24 patients who underwent SIJ fusions between May 2015 and October 2017 performed by a single surgeon. RESULTS: Mean total satisfaction score was 89.0% +/- 27.6%. A statistically significant reduction (P = 0.0028) in low back pain scores was noted from an average baseline score of 6.6 +/- 2.4 to 3.7 +/- 3.3 postoperatively. Leg pain scores decreased from 4.8 +/- 3.8 to 1.5 +/- 2.9 (P = 0.0034). Mean surgical time was 53.0 +/- 13.9 minutes. It took significantly longer (P = 0.0089) to perform the initial 13 cases (59.9 +/- 15.2 minutes) compared with subsequent cases (45.4 +/- 7.3 minutes). Estimated blood loss was minimal (10.4 +/- 5.2 mL). CONCLUSIONS: Minimally invasive SI joint fusion using cylindrical threaded implants can be safely performed with minimal morbidity and good clinical outcomes.