Randomized controlled trial of percutaneous intradiscal radiofrequency thermocoagulation for chronic discogenic back pain - Lack of effect from a 90-second 70 C lesion

Study Design. A prospective double-blind randomized trial in 28 patients. Objectives. To assess the clinical effect of percutaneous intradiscal radio frequency thermocoagulation for reducing pain, functional disability, and p hysical impairment in patients with chronic discogenic low back pain. Summary of Background Data. Chronic discogenic low back pain is a challengi ng problem in western countries. A treatment option is radiofrequency heati ng of the affected disc. Its clinical efficacy has never been formally test ed in a controlled trial. Methods. Twenty-eight patients with a history of at least 1 year of chronic low back pain were selected on the basis of a diagnostic anesthetization o f the lower intervertebral discs. Only patients with one putative painful l evel were selected and randomly assigned to one of two treatment groups. Ea ch patient in the radiofrequency treatment group (n = 13) received a 90-sec ond 70 C lesion of the intervertebral disc. Patients in the control group ( n = 15) underwent the same procedure, but without use of radiofrequency cur rent. Both the treating physician and the patients were blinded to the grou p assignment. Before treatment, physical impairment, rating of pain, the de gree of disability, and quality of life were assessed by a blinded investig ator. Results. Eight weeks after treatment, there was one success in the radiofre quency group (n = 13) and two in the control group (n = 15). The adjusted a nd unadjusted odds ratio was 0.5 and 1.1, respectively (not significant). A lso, visual analog scores for pain, global perceived effect, and the Oswest ry disability scale showed no differences between the two groups. Conclusions. Percutaneous intradiscal radiofrequency thermocoagulation (90 seconds, 70 C) is not effective in reducing chronic discogenic low back pai n.