Prospective, randomized, multicenter study of intraosseous basivertebral nerve ablation for the treatment of chronic low back pain: 24-Month treatment arm results

Abstract

Background: Vertebral endplates, innervated by the basivertebral nerve, can be a source of vertebrogenic low back pain when damaged with inflammation, visible as types 1 or 2 Modic changes. A randomized controlled trial (RCT) compared basivertebral nerve ablation (BVNA) to standard care (SC) showed significant differences between arms at 3 and 6-months. At 12-months, significant improvements were sustained for BVNA. We report results of the BVNA arm at 24-months.

Methods: Prospective, open label, single-arm follow-up of the BVNA treatment arm of a RCT in 20 US sites with visits at 6-weeks, and 3, 6, 9, 12 and 24-months. Paired comparisons to baseline were made for the BVNA arm at each timepoint for Oswestry Disability Index (ODI), Visual Analog Scale (VAS), Short Form Health Survey (SF-36), EQ-5D-5L, and responder rates.

Results: 140 patients were randomized, 66 to BVNA. In the 58 BVNA patients completing a 24-month visit, 67% had back pain for >5 years, 36% were actively taking opioids at baseline, 50% had prior epidural steroid injections, and 12% had prior low back surgery. Improvements in ODI, VAS, SF-36 PCS, and EQ-5D-5L were statistically significant at all timepoints through 2 years. At 24 months, ODI and VAS improved 28.5±16.2 points (from baseline 44.5; p < 0.001) and 4.1±2.7 cm (from baseline 6.6; p < 0.001), respectively. A combined responder rate of ODI≥15 and VAS≥2 was 73.7%. A ≥50% reduction in pain was reported in 72.4% of patients and 31.0% were pain-free at 2 years. At 24 months, only 3(5%) of patients had BVNA-level steroid injections, and 62% fewer patients were actively taking opioids. There were no serious device or device-procedure related adverse events reported through 24 months.

Conclusion: Intraosseous BVNA demonstrates an excellent safety profile and significant improvements in pain, function, and quality of life that are sustained through 24 months in patients with chronic vertebrogenic low back pain.

Keywords: AE, Adverse Events; ANCOVA, Analysis of Covariance; BVN, Basivertebral Nerve; BVNA, Basivertebral Nerve Ablation; Basivertebral nerve; Basivertebral nerve ablation; CLBP, Chronic Low Back Pain; Chronic low back pain; DMC, Data Management Committee; ESI, Epidural Steroid Injection; LS, Least Squares; MCID, Minimal Clinically Important Difference; Modic; ODI, Oswestry Disability Index; QOL, Quality of Life; RCT, Randomized Controlled Trial; RDQ, Roland-Morris Disability Questionnaire; Radiofrequency ablation; SC, Standard Care; VAS, Visual Analog Scale; Vertebrogenic pain.

Fig. 1

Patient disposition flow diagram. At the point of enrollment halt due to statistical superiority at an interim analysis, 140 participants were randomized (66-BVN Ablation, 74-SC) in the study. After a blinded re-baseline, the remaining SC arm patients (n = 66) were offered BVN ablation, with 61(92%) electing to cross to active treatment (N = 61); of whom 3 were lost to follow-up. In the BVN ablation treatment arm 58 of the 66 randomized had a 24-month follow-up visit (a retention rate of 88%). Details on reasons for study exit are reported for each follow-up time point. Abbreviations: ODI, Oswestry Disability Index; VAS, visual analogue scale; BMI, body mass index; BVN, basivertebral nerve.

Fig. 2

Mean oswestry disability index (ODI) over time. This graph depicts the mean ODI at each study follow-up for each arm of the RCT through the longer-term follow-up of the BVNA arm. A statistically significant and clinically meaningful difference in mean ODI was observed from baseline/re-baseline for each timepoint in patients treated with BVN ablation, including in control patients that crossed to active treatment. Abbreviations: ODI, Oswestry Disability Index; BVNA, basivertebral nerve ablation.

Fig. 3

Mean visual analog scale (VAS) over time. This graph depicts the mean VAS at each study follow-up for each arm of the RCT through the longer-term follow-up of the BVNA arm. A statistically significant and clinically meaningful difference in mean VAS was observed from baseline/re-baseline for each timepoint in patients treated with BVN ablation, including in control patients that crossed to active treatment. Abbreviations: VAS, visual analogue scale; BVNA, basivertebral nerve ablation.

Fig. 4

Visual analog scale (VAS) pain reduction by quadrant of improvement. At 2 years post BVN ablation, 72.4% of patients in the BVNA treatment arm with a 24 month visit, reported a greater than 50% reduction in pain from baseline and 31.0% had complete pain relief. Abbreviations: VAS, visual analogue scale; BVNA, basivertebral nerve ablation.