脊椎ジャーナル

Serum Beta-endorphin Changes in Lumbar Facet Syndrome Treated with Radiofrequency Lumbar Facet Denervation - A Randomized Controlled Study

Abstract

Tsou HK, Kao TH, Tsai PA, Chen HT, Pan HC and Wei JCC

Background: Lumbar facet joint has been considered a significant source of chronic low back pain (LBP). Radiofrequency (RF) lumbar facet denervation is an effective treatment modality for patients with lumbar facet syndrome (LFS). We propose this protocol to study the effect of RF and the change in serum beta-endorphin level in the treatment of LFS.

Methods: This open-label, parallel, randomized controlled clinical trial enrolled patients with LFS. The study subjects were randomly assigned equally into two arms. The treatment arm received percutaneous RF and the control arm received medical treatment using non-steroidal anti-inflammatory drugs (NSAIDs). Patients were evaluated at days 0, 7 and 28 after randomization. Primary endpoints were the pain visual analogue scale on day 28. Secondary endpoints were visual analogue scale on day 7, quality of life evaluation using short-form 36 (SF-36) questionnaires and serum beta-endorphin level on days 0, 7 and 28.

Results: Until August of 2008, twenty-five patients were enrolled, including eleven in the treatment arm and fourteen in the control arm. Baseline characteristics between these two arms were comparable regarding age, sex, pain intensity, serum beta-endorphin level and short-form 36 score. The mean postoperative 7-day visual analogue pain scale for patients who had LBP in the control and treatment arm was 6.5 and 3.0. The mean postoperative 28-day visual analogue pain scale for patients who had LBP in the control and treatment arms was 6.0 and 2.5. On average, patients in the treatment arm had reduction of serum beta-endorphin compared to the control arm on day 7 (38.5% vs 0, p=0.141) and day 28 (37.9% vs 0, p=0.621).

Conclusion: RF lumbar facet denervation is an effective treatment modality and better than NSAIDs for patients with LFS. RF lumbar facet denervation demonstrated a trend to reduce serum beta-endorphin levels, although not statistically significant.