5-year longitudinal follow-up of patients treated for chronic mechanical low back pain using restorative neurostimulation

Abstract

Background: Chronic mechanical low back pain (CLBP) often stems from dysfunction of the multifidus muscle, leading to impaired motor control and pain. Restorative neurostimulation has emerged as a novel treatment targeting this dysfunction by delivering electrical stimulation to the medial branches of the L2 dorsal rami to restore multifidus activation. Methods: This prospective, open-label, postmarket clinical follow-up study aimed to evaluate 5-year clinical outcomes and device utilization trends in a cohort of 42 patients with CLBP treated across five UK sites with restorative neurostimulation via an implanted ReActiv8 neurostimulation system. Patients were followed for 5 years, with assessments of pain (Numerical Rating Scale (NRS)), disability (Oswestry Disability Index (ODI)), and health-related quality of life (EuroQol-5 Dimension, 5 Level (EQ-5D-5L)) at baseline and regular intervals. Therapy utilization was collected via implantable device logs. Results: At 5 years, 34/42 patients (81%) completed follow-up. Significant and durable improvements were observed in pain (mean NRS reduced from 7.0 to 3.2), disability (mean ODI reduced from 46.6 to 26.1), and quality of life (EQ-5D index increased from 0.426 to 0.703). A total of 82% of patients achieved a minimally clinically important change in either pain or disability, and 62% were pain remitters (NRS ≤3). Device usage averaged 1106 hours over 5 years, with reductions in usage over time. Lower usage was associated with non-response, though causality could not be determined. Conclusions: Restorative neurostimulation provides robust, sustained improvements in pain, function, and quality of life in patients with CLBP associated with multifidus dysfunction. These results support its long-term efficacy and safety in real-world clinical practice. Trial registration number: ClinicalTrials.gov Identifier: NCT01985230.