Objectives: Radiofrequency facet joint denervation procedures have been common practice for 2 decades in treatment of chronic low back pain. We designed this multicenter, randomized, double-blind, sham treatment controlled trial to determine the efficacy of radiofrequency facet joint denervation, as it is routinely performed.
Methods: Inclusion criteria were low back pain, duration more than 6 months, and >or=50% Visual Analog Scale (VAS) reduction on diagnostic block. Exclusion criteria were prior radiofrequency treatment, radicular syndrome, coagulopathies, specific allergies, cancer, and pregnancy. A total of 81 out of 462 patients were randomized to undergo radiofrequency facet joint denervation or sham treatment. The first evaluation was carried out 3 months after treatment. Primary outcome was determined with a combined outcome measure comprising VAS, physical activities, and analgesic intake, from a twice-weekly recorded diary. Secondary outcome measures were the separate diary parameters, global perceived effect (complete relief, >50% relief, no effect, pain increase), and SF-36 Quality of Life Questionnaire.
Results: There were no dropouts before the first evaluation. The combined outcome measure showed no differences between radio- frequency facet joint denervation (n=40; success 27.5%) and sham (n=41; success 29.3%) (P=0.86). The VAS in both groups improved (P<0.001). Global perceived effect improved after radiofrequency facet joint denervation (P<0.05). The other secondary outcome parameters showed no significant differences. Relevant costs were evaluated.
Discussion: The combined outcome measure and VAS showed no difference between radiofrequency and sham, though in both groups, significant VAS improvement occurred. The global perceived effect was in favor of radiofrequency. In selected patients, radiofrequency facet joint denervation appears to be more effective than sham treatment.