Comparative Analysis of Surgical Sacroiliac Fusion and Radiofrequency Ablation – A Retrospective Cohort Study

Introduction: Treatment of lower back pain originating from the Sacroiliac (SI) joint is challenging, with SI joint radiofrequency ablation (RFA) and surgical SI joint fusion (SI fusion) being used for refractory pain. This study aimed to report the trends in the total number of SI RFA and fusion, the post-procedure healthcare utilization, and associated costs and stratify the analysis based on sex.

Methods: This retrospective cohort study was conducted using PearlDiver. Starting in January 2020, patients were divided into RFA and SI fusion cohorts. Trends were included until the first quarter of 2023, while for other outcomes, patients till the first quarter of 2022 were included, with a one-year follow-up. Quarterly trends for the total number of procedures, total reimbursements, and average reimbursement per patient were included. For healthcare utilization, physical therapy, office visits, emergency department (ED) visits, computed tomography (CT) scans, magnetic resonance imaging (MRI) scans, opioid prescriptions, and nonsteroidal anti-inflammatory drugs (NSAIDs) were included. Sex-based subgroup analysis was performed as well.

Results: This study included 20,448 patients, 12,581 (62.8%) in the RFA cohort and 7,597 (37.2%) in the SI fusion cohort. 69.8% of the patients were females. RFA patients were more likely to be older, have type-2 diabetes mellitus, have a higher Elixhauser Comorbidity Index (ECI), and have lower mean family income. The overall number of RFA per quarter has remained higher than the total number of SI fusions per quarter, but the overall gap has gradually narrowed. From 2020 Q1 to 2023 Q1, RFAs have decreased by 155 fewer procedures per quarter, while SI fusions have increased by 331 more procedures per quarter. The changes in the numbers were more pronounced in females. The average reimbursement also dropped for RFA ($396 to $348) and increased for SI fusions ($4,127 to $4,242). For females, RFA reimbursements dropped more sharply ($408 to $341), but also increased more sharply for SI fusion ($3,928 to $4,337).

Conclusion : More patients are currently undergoing RFA than SI fusion, but the gap is narrowing, especially in females. RFA has higher healthcare-associated costs at one-year follow-up and a decreasing average reimbursement per patient.