ORIGINAL ARTICLE Cooled Radiofrequency System for the Treatment of Chronic Pain from Sacroiliitis: The First Case-Series Leonardo Kapural, MD, PhD; Fady Nageeb, MD; Miranda Kapural, MD; Juan P Cata, MD; Samer Narouze, MD; Nagy Mekhail, MD, PhD Department of Pain Management, Cleveland Clinic, Cleveland, Ohio, U.S.A.  Abstract: Sacroiliitis and sacroiliac (SI) joint dysfunction are frequent causes of the chronic lower back pain. Thera- peutic solutions include intra-atricular injections with short-term pain relief and surgical fusion, which appears ineffective. Radiofrequency (RF) of the joint capsule or lateral branches has been previously reported with variable successes. Cooling tissue adjacent to the electrode (cooled RF) increases the radius of lesion. We present here the first retrospective data on pain relief and changes in function after such RF denervation. We reviewed electronic records of 27 patients with chronic low back pain (median 5 years) who underwent cooled RF of S1, S2, and S3 lateral branches and of dorsal ramus (DR) L5 following two diagnostic SI joint blocks (>50% of pain relief). Patient sample consisted of 20 women and 7 men, 38 to 92 years old. Pain disability index (PDI), visual analog scale (VAS) pain scores, global patient satisfaction (GPE) and opioid use before and 3–4 months after the pro- cedure were analyzed. One patient had an incomplete chart. Observed were improvements in function (PDI) from 32.7 1 9.9 to 20.3 1 12.1 (P < 0.001) and VAS pain scores 7.1 1 1.6 to 4.2 1 2.5 (P < 0.001) at 3–4 months after the pro- cedure. Opioid use decreased from median 30 to 20 mg mor- phine equivalent. Eighteen patients rated their improvement in pain scores using GPE as improved or much improved, while eight claimed minimal or no improvement. The majority of patients with chronic SI joint pain experi- enced a clinically relevant degree of pain relief and improved function following cooled RF of sacral lateral branches and DR of L5 at 3–4 months follow-up.  Key Words: sacroiliitis, radiofrequency denervation, chr- onic lower back pain INTRODUCTION The sacroiliac (SI) joint complex is a common source of chronic lower back pain. The prevalence among patients with idiopathic low back pain is reported as 18% to 30%. 1,2 The impact on patient disability and quality of life is equivalent to other well-characterized pain gen- erators in the spine. 3 A detailed etiology of SI joint complex mediated pain has not been reported, however both intra- and extra-articular influences have been implicated. 4 Trauma, parturition, and lumbar spinal fusion are all likely inciting factors in the development of chronic SI joint pain. 4 Therapeutic solutions are few and include intra-atricular injections, with rather short- term pain relief, 5 and surgical solutions like joint fusion, which appears to be ineffective. 6 The joint is predomi- nantly innervated by posterior primary rami, 7–9 with a Address correspondence and reprint requests to: Leonardo Kapural, MD, PhD, Department of Pain Management, Cleveland Clinic, 9500 Euclid Ave Desk C25, Cleveland, OH 44195, U.S.A. E-mail: Kapural@ccf.org. Submitted: May 27, 2008; Accepted: July 13, 2008 DOI. 10.1111/j.1533-2500.2008.00231.x © 2008 World Institute of Pain, 1530-7085/08/$15.00 Pain Practice, Volume 8, Issue 5, 2008 348–354