Background:Recalcitrant sacroiliac joint pain responds well to minimally-invasive surgical (MIS) techniques, although long-term radiographic and fusion data are limited.Objective:To evaluate the one-year clinical results from a cohort of patients with chronic sacroiliac (SI) joint pain unresponsive to conservative therapies who have undergone minimally invasive SI joint fusion.Methods:SI joint fusion was performed between May 2011 and January 2014. Outcomes included radiographic assessment of fusion status, leg and back pain severity via visual analog scale (VAS), disability via Oswestry Disability Index (ODI) and complication rate. Outcomes were measured at baseline and at follow-up appointments 6 months and 12 months post-procedure.Results:Twenty minimally invasive SI joint fusion procedures were performed on 18 patients (mean age: 47.2 (14.2), mean BMI: 29.4 (5.3), 56% female). At 12 months, the overall fusion rate was 88%. Back and leg pain improved from 81.7 to 44.1 points (p<0.001) and from 63.6 to 27.7 points (p=0.001), respectively. Disability scores improved from 61.0 to 40.5 (p=0.009). Despite a cohort containing patients with multiple comorbidities and work-related injuries, eight patients (50%) achieved the minimal clinically important difference (MCID) in back pain at 12 months, with 9 (69%) patients realizing this improvement in leg pain and 8 (57%) realizing the MCID in ODI scores at 12 months. No major complications were reported.Conclusion:Minimally invasive SI joint surgery is a safe and effective procedure, with a high fusion rate, a satisfactory safety profile and significant improvements in pain severity and disability reported through 12 months post-procedure.