Pulsed Dose Radiofrequency Before Ablation of Medial Branch of the Lumbar Dorsal Ramus for Zygapophyseal Joint Pain Reduces Post-procedural Pain.

BACKGROUND One of the potential side effects with radiofrequency ablation (RFA) includes painful cutaneous dysesthesias and increased pain due to neuritis or neurogenic inflammation. This pain may require the prescription of opioids or non-opioid analgesics to control post-procedural pain and discomfort. OBJECTIVES The goal of this study is to compare post-procedural pain scores and post-procedural oral analgesic use in patients receiving continuous thermal radiofrequency ablation versus patients receiving pulsed dose radiofrequency immediately followed by continuous thermal radiofrequency ablation for zygopophaseal joint disease. STUDY DESIGN This is a prospective, double-blinded, randomized, controlled trial. Patients who met all the inclusion criteria and were not subject to any of the exclusion criteria were required to have two positive diagnostic medial branch blocks prior to undergoing randomization, intervention, and analysis. SETTING University hospital. METHODS Eligible patients were randomized in a 1:1 ratio to either receive thermal radiofrequency ablation alone (standard group) or pulsed dose radiofrequency (PDRF) immediately followed by thermal radiofrequency ablation (investigational group), all of which were performed by a single Board Certified Pain Medicine physician. Post-procedural pain levels between the two groups were assessed using the numerical pain Scale (NPS), and patients were contacted by phone on post-procedural days 1 and 2 in the morning and afternoon regarding the amount of oral analgesic medications used in the first 48 hours following the procedure. RESULTS Patients who received pulsed dose radiofrequency followed by continuous radiofrequency neurotomy reported statistically significantly lower post-procedural pain scores in the first 24 hours compared to patients who received thermal radiofrequency neurotomy alone. These patients also used less oral analgesic medication in the post-procedural period. LIMITATIONS These interventions were carried out by one board accredited pain physician at one center. The procedures were exclusively performed using one model of radiofrequency generator, at one setting for the PDRF and RFA. The difference in the number of levels of ablation was not considered in the analysis of the results. CONCLUSION Treating patients with pulsed dose radiofrequency prior to continuous thermal radiofrequency ablation can provide patients with less post-procedural pain during the first 24 hours and also reduce analgesic requirements. Furthermore, the addition of PDRF to standard thermal RFA did not prolong the time of standard thermal radiofrequency ablation procedures, as it was performed during the typically allotted time for local anesthetic action. KEY WORDS Low back pain, facet joint disease, medial branch block, Radiofrequency ablation, thermal radiofrequency, pulsed dose radiofrequency, PDRF, zygapophyseal joint.