MR-guided lumbar facet radiofrequency denervation for treatment of patients with chronic low back pain in an open 1.0 Tesla MRI system

Background: To evaluate the feasibility, safety and efficacy of magnetic resonance imaging (MRI)-guided lumbar facet joint radiofrequency denervation (FRD) in patients with chronic low back pain. Methods: The study consisted of two parts. First, a preclinical analysis using an ex vivo animal model was performed to define optimal technical parameters for ablation. Then, 17 patients with chronic lumbar facet joint pain syndrome were prospectively included and underwent MRI-guided FRD in an open 1.0-Tesla MRI. We analyzed technical feasibility and complications as well as clinical outcome in terms of subjective pain assessed on a numerical visual analogue scale (VAS) before and after 1 week/6 months after FRD. Clinical assessment was complemented by measurement of paravertebral muscle volume and fat content before the intervention and at 6-month follow-up. Results: All interventions were technically successful without major complications. Initial VAS scores (median: 8, IQR: 1, range: 6-9, CI: 7.14-8.04) decreased significantly both after one week (median: 4, IQR: 5, range: 0-7, CI: 1.9-4.69, P=0.003) and after 6 months (median: 1, IQR: 6, range: 0-7, CI: 1.064.23, P< 0.001). Mean multifidus muscle volume increased significantly in the patient population (from 366.8 +/- 130.8 cm(3) before to 435.4 +/- 146.7 cm(3) after FRD, P=0.031). Conclusions: This proof of principle study shows MRI-guided FRD in an open 1.0-Tesla MRI system to be a potential therapy option for patients with chronic low back pain.