Abstract
BACKGROUND: High-impact chronic low back pain (CLBP) correlates with high healthcare resource utilization. Therapies that can alter impact status may provide beneficial long-term economic benefits. An implantable restorative neurostimulation system (ReActiv8, Mainstay Medical) designed to over-ride multifidus inhibition to facilitate motor control restoration, thereby resolving mechanical low back pain symptoms, has shown significant durable clinical effects in moderately and severely impacted patients. OBJECTIVE: To examine changes in high-impact chronic low back pain in patients treated with restorative neurostimulation at 2 years. METHODS: ReActiv8-B is a prospective, international, multicenter trial to evaluate the safety and efficacy of restorative neurostimulation in patients with intractable CLBP and no prior surgery. For this longitudinal subanalysis, patients were stratified into low-, moderate-, and high-impact CLBP categories using the US Department of Health and Human Services definition comprising pain intensity, duration, and impact on work, self-care, and daily activities. RESULTS: Of 2-year completers (n = 146), 71% had high-impact CLBP at baseline and this proportion reduced to 10%, with 85% reporting no or low impact. This corresponds with measurements of HRQoL returning to near-population norms. CONCLUSION: In addition to clinically meaningful improvements in pain and function with long-term durability, the overwhelming majority of patients transitioned from a high- to a no- or low-impact CLBP state. This is typically associated with significantly lower healthcare-utilization levels. The of recovery trajectory is consistent with a restorative mechanism of action and suggests that over the long term, the improvement in these health states will be maintained.