Background: Sacroiliac joint (SIJ) dysfunction contributes to 15–30% of chronic low back pain cases and is often difficult to diagnose due to overlap with other spinal pain syndromes. Conventional fluoroscopy-guided radiofrequency ablation (RFA) targets the lateral branches of the S1–S3 sacral dorsal rami and the L5 dorsal ramus but may be limited by anatomical variability. Endoscopic radiofrequency ablation (ERFA) enables direct visualisation of SIJ neural anatomy and may improve treatment precision and durability.
Aim: To compare pain-free survival, pain reduction, and functional improvement following ERFA versus conventional RFA in patients with chronic SIJ dysfunction over 24 months.
Methods: This retrospective cohort study will include adults treated with either ERFA or conventional RFA for confirmed SIJ dysfunction at a single institution between January 2021 and May 2026. Diagnosis will be confirmed using positive diagnostic lateral branch blocks. Patients with spinal infection, malignancy, coagulopathy, or pregnancy will be excluded. Outcomes will include pain-free survival, pain intensity (VAS/NRS), and disability (ODI), assessed at baseline, 6 weeks, and 3, 6, 12, and 24 months. Kaplan–Meier survival analysis and linear mixed-effects modelling will compare outcomes between groups.
Expected Outcomes: ERFA is hypothesised to provide longer pain-free survival and greater sustained improvements in pain and function than conventional RFA. Existing evidence suggests favourable outcomes and safety, although current studies are limited by small sample sizes, non-randomised designs, and short follow-up.
Significance: By incorporating functional outcomes and extended follow-up, this study aims to strengthen the evidence base for interventional management of refractory SIJ dysfunction and inform clinical decision-making.