Comparative Outcomes of Cooled Versus Traditional Radiofrequency Ablation of the Lateral Branches for Sacroiliac Joint Pain

Objectives: Sacroiliac joint pain is a common cause of low back pain (LBP). Cooled radiofrequency ablation (c-RFA) of the lateral branches was recently introduced with the hypothesis that it creates larger lesions to overcome the anatomic variability of the lateral branches and achieve better outcomes as compared with the traditional radiofrequency approach (t-RFA). The objective of this comparative study is to determine if c-RFA is superior over t-RFA in providing longer pain relief. Methods: Data on 88 patients were retrospectively collected between January 2006 and June 2009. Patients' pain relief was registered as < 50%, 50% to 80%, or > 80% at 1, 3, 6, and 12 months after procedure. The duration of pain relief, defined as the time until the patient reported < 50% pain relief, served as our primary outcome. Demographic, morphometric, and procedural characteristics were analyzed using standard descriptive statistics and univariable tests. The relationship between RFA technique and duration of pain relief was evaluated using multivariable Cox regression. Results: Among the 88 patients, 30 received t-RFA and 58 received c-RFA. We did not find a significant univariable relationship between RFA technique and duration of pain relief either before (P = 0.76, Sun test) or after (P = 0.95, Wald test) adjusting for the potentially confounding variables. Both cooled and traditional RFAs provided > 50% pain reduction for 3 to 6 months in majority of the patients. Discussion: This study did not reveal evidence that c-RFA of the lateral branches provides longer relief of sacroiliac joint pain as compared with t-RFA.