Background Chronic lower back pain is a significant global health issue, leading to disability and a substantial economic burden. A considerable number of cases are associated with the sacroiliac joint (SIJ), especially among patients with a history of lumbar fusions. Despite various treatments, persistent SIJ pain often requires surgical intervention, with minimally invasive techniques becoming the standard due to their benefits over open surgery. This study examines the clinical outcomes of a novel minimally invasive SIJ fixation technique using the Trident™ system. Methodology The study retrospectively reviewed 39 patients who underwent SIJ fusion with the Trident™ system across four surgical sites by a single surgeon. Strict inclusion and exclusion criteria ensured a homogeneous patient population. The procedure involved placing hollow fenestrated screws in a tri-pronged fashion across the SIJ to achieve fusion. The Oswestry Disability Index (ODI) was used to measure functional outcomes, and statistical analyses were conducted to assess the efficacy of the procedure. Results The study found statistically significant improvements in most ODI categories postoperatively. Subgroup analyses revealed that patients with bilateral SIJ fusions showed the greatest improvement, while those with unilateral fusions without prior lumbar surgery showed the least improvement, though still significant. The results suggest that the Trident™ system is effective in improving patient outcomes. Conclusions Evidence indicates that the novel SIJ fixation technique could influence future standards of care for SIJ-related chronic low back pain. The Trident™ Screw System's minimally invasive approach to SIJ fusion is effective in improving functional outcomes for patients with chronic SIJ-related lower back pain. The technique's efficacy, demonstrated through significant ODI improvements, supports its potential as a valuable treatment option.