Lumbar medial branch radiofrequency neurotomy (RFN), a common treatment for zygapophyseal joint pain, may be therapeutically ineffective and could contribute to disc degeneration, according to a recent study, 1 which considered the therapeutic and/or potentially negative effects of the procedure on the lumbar multifidus muscle cross-sectional area (CSA), including facet joint degeneration, or intervertebral disc degeneration. The findings of the study suggest that while the procedure remains an effective low-back pain deterrent, patients undergoing RFN show little-to-no difference in multifidus cross-sectional rates of deterioration in the zygapophyseal joints and have a greater potential for progressive disc degeneration than than untreated subjects.
Retrospective data from an academic spine treatment center was collected from 27 patients who had been treated over the course of six years. The subjects in the study had completed at least one RFN lumbar medial branch procedure, had never undergone spinal surgery, and had received magnetic resonance (MR) imagery prior to and after their RFN procedure. Each patient’s gender, age, back pain duration, pre-and post-RFN imagery, and date of RFN were recorded, as well as the history of potentially contributive medical conditions affecting the lumbar spine. The mean age of the observed subjects was 55.6 years old, and 40 percent of the subjects were male.
The MR images were viewed and analyzed by a single, unblended physician investigator, and measurements of the intervertebral disc and facet joint degeneration grade were taken for all lumbar segmental levels. The Pfirrmann grading scale was used to identify and measure any noted disc degeneration. The Weishapt lumbar facet joint disease severity grading scale, which uses a rating of 0-3 to classify any noted facet joint degeneration, was used to identify and grade evidence of joint disease present in the pre-and post-RFN imagery. The data was then further classified into two groups—those affected by RFN treatment, and those whose levels appeared unaffected by treatment.
Though there appeared to be a clinically insignificant trend toward CSA, the reviewed data suggested no real change in facet degeneration but a significant increase in post-RFN rates of disc degeneration in the study subjects. The authors of the study emphasize the importance of RFN in the treatment of lower back pain and demur from concluding that the risks of the procedure outweigh the benefits of treatment. However, they claim the findings suggest a need for further research to determine the efficacy and risks of RFN as it relates to multifidus morphology, segmental anatomy, and degenerative disc disease.