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 radiofrequency thermocoagulation for reducing pain, functional disability, and physical impairment in patients with chronic discogenic low back pain.

SUMMARY OF BACKGROUND DATA: Chronic discogenic low back pain is a challenging problem in western countries. A treatment option is radiofrequency heating of the affected disc. Its clinical efficacy has never been formally tested 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 of the lower intervertebral discs. Only patients with one putative painful level were selected and randomly assigned to one of two treatment groups. Each patient in the radiofrequency treatment group (n = 13) received a 90-second 70 C lesion of the intervertebral disc. Patients in the control group (n = 15) underwent the same procedure, but without use of radiofrequency current. Both the treating physician and the patients were blinded to the group assignment. Before treatment, physical impairment, rating of pain, the degree of disability, and quality of life were assessed by a blinded investigator.

RESULTS: Eight weeks after treatment, there was one success in the radiofrequency group (n = 13) and two in the control group (n = 15). The adjusted and unadjusted odds ratio was 0.5 and 1.1, respectively (not significant). Also, visual analog scores for pain, global perceived effect, and the Oswestry 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 pain.