1. 2025;28;S191-S202Six-Month Interim Outcomes of the SPARTAN Study: A Prospective, Multicenter, Post-Market Surveillance Study on a Modular SI Joint Fusion System
   Prospective Study
   Samuel P. Brown, DO, Lee James, DO, Gregory Moore, MD, Caitlin Tourje, MD, Farid Kia, MD, Alireza Katouzian, MD, Philip Sasso, MD, Emmanuel Gage, MD, Robert Michael Hullander, MD, Michael Drass, MD, and Brian Durkin, DO.

BACKGROUND: Low back pain (LBP) is the most common type of pain reported by adults and the leading cause of disability globally. The sacroiliac joint (SIJ)—the large, load-bearing joint that connects the pelvis and lower spine—is one of the most underrecognized causes of LBP and has been determined to be a source of the condition in 10–38% of cases. While SIJ fusion has been shown to be a superior alternative to the long-term conservative management of SIJ dysfunction, many early SIJ fusion techniques have resulted in high incidences of adverse events (AEs) and serious adverse events (SAEs), long recovery times, and, often, the need for revision surgeries. 

OBJECTIVES: To prospectively assess the effectiveness of a minimally invasive lateral oblique approach to SIJ fusion that uses TransLoc 3DTM Sacroiliac Joint Fusion System (CornerLoc™) compression screws, based on patient-reported outcome measures of pain and functional improvement. 

STUDY DESIGN: Prospective study. 

SETTING: Seventeen pain centers across the United States. 

METHODS: Between November 13, 2023, and December 31, 2024, 114 patients underwent SIJ fusion via TransLoc 3DTM SIJ fusion compression screws in a procedure that used a minimally invasive lateral oblique approach. Outcomes for pain and functional improvement were assessed both before the procedure and at 3 (n = 85) and 6 (n = 72) months after it. Those outcomes were measured on the Numeric Rating Scale (NRS), Oswestry Disability Index (ODI), and Quebec Back Pain Disability Scale (QBPDS). Additionally, the safety and efficacy of the procedure were assessed using a composite endpoint comprising improvement in both NRS and ODI scores as well as the absence of AEs or SAEs. Comparisons between the groups of patients were performed using Student’s t-test for continuous data or Fisher’s exact test for categorical data. Mixed models for repeat measures were used to model factors associated with each endpoint longitudinally and generalized linear models for interim tests. All patients provided consent to participate in the study, and approval was obtained from the institutional review board (approval number 1356747).

RESULTS: The average age of the patients at the baseline was 67.1 ± 10.5 years, and 70.8% were female. Our results show significant improvements in pain and functional outcomes from the baseline, as assessed by both the composite endpoint and individual measures (i.e., NRS, ODI, and QBPDS), 3 and 6 months after the procedure (P < 2.2 e-16 for all measures). Furthermore, 72.94% of patients reported improvements in both their NRS pain scores and ODI function scores within 3 months, while 90.3% reported an improvement at 6 months. Additionally, 84.7% of patients reported an improvement in their QBPDS scores within 6 months. A significant majority of patients experienced greater than 20% improvement in all outcome measures at 3 and 6 months (P < 2.16e-16). No AEs or SAEs were reported as results of the SIJ fusion procedure. 

LIMITATIONS: Patients reported the outcomes, and the analysis had only a single arm.

CONCLUSIONS: The results of the present study show that patients received significant benefits from a minimally invasive lateral oblique approach to SIJ fusion that used 3D-printed titanium compression screws. 

KEY WORDS: Low back pain, sacroiliac joint, arthrodesis, SIJ fusion, minimally invasive surgery, lateral oblique approach, pain reduction, 3D printed titanium, surface porosity, sacroiliitis, compression, outcome measures