Fusion and patient-reported outcomes after navigated decortication and direct arthrodesis in minimally invasive sacroiliac joint fusion using cylindrical threaded implants: a case series and literature review.

OBJECTIVE: Sacroiliac joint (SIJ) dysfunction is a significant cause of back pain. Despite recent advances in minimally invasive (MIS) SIJ fusion, the fusion rate remains controversial. This study sought to demonstrate that a navigated decortication and direct arthrodesis technique in MIS SIJ fusion would result in satisfactory fusion rates and patient-reported outcomes (PROs).

METHODS: The authors retrospectively reviewed consecutive patients who underwent MIS SIJ fusion from 2018 to 2021. SIJ fusion was performed using cylindrical threaded implants and SIJ decortication employing the O-arm surgical imaging system and StealthStation. The primary outcome was fusion, evaluated using CT at 6, 9, and 12 months postoperatively. Secondary outcomes included revision surgery, time to revision surgery, visual analog scale (VAS) score for back pain, and the Oswestry Disability Index (ODI), measured preoperatively and 6 and 12 months postoperatively. Patient demographics and perioperative data were also collected. PROs over time were analyzed using ANOVA followed by a post hoc analysis.

RESULTS: One hundred eighteen patients were included in this study. The mean (± SD) patient age was 58.56 ± 13.12 years, and most patients were female (68.6% vs 31.4% male). There were 19 smokers (16.1%) with an average BMI of 29.92 ± 6.73. One hundred twelve patients (94.9%) underwent successful fusion on CT. The ODI improved significantly from baseline to 6 months (Δ7.73, 95% CI 2.43-13.03, p = 0.002) and from baseline to 12 months (Δ7.54, 95% CI 1.65-13.43, p = 0.008). Similarly, VAS back pain scores improved significantly from baseline to 6 months (Δ2.31, 95% CI 1.07-3.56, p < 0.001) and from baseline to 12 months (Δ1.63, 95% CI 0.25-3.00, p = 0.015).

CONCLUSIONS: MIS SIJ fusion with navigated decortication and direct arthrodesis was associated with a high fusion rate and significant improvement in disability and pain scores. Further prospective studies examining this technique are warranted.