Restorative Neurostimulation Therapy Compared to Optimal Medical Management: A Randomized Evaluation (RESTORE) for the Treatment of Chronic Mechanical Low Back Pain due to Multifidus Dysfunction
Frank J. Schwab, Nagy Mekhail, Kiran V. Patel, Meredith Langhorst, Robert Heros, Jonathan Gentile, Sherif Costandi, Gregory Moore, C. J. Gilmore, Smith Manion, Krishnan Chakravarthy, S. Craig Meyer, Justin Bundy, Jordan Tate, Rebecca Sanders, Sandeep Vaid, Oszkar Szentirmai, Johnathan Goree, Vikas V. Patel, Jeff A. Lehmen, Mehul J. Desai, Jason E. Pope, Anthony Giuffrida, Salim S. Hayek, Sohrab Virk, Richard Paicius, William R. Klemme, Robert J. Levy, Christopher A. Gilligan, the RESTORE investigators
Abstract
Many interventional strategies are commonly used to treat chronic low back pain (CLBP), though few are specifically intended to target the distinct underlying pathomechanisms causing low back pain. Restorative neurostimulation has been suggested as a specific treatment for mechanical CLBP resulting from multifidus dysfunction. In this randomized controlled trial, we report outcomes from a cohort of patients with CLBP associated with multifidus dysfunction treated with restorative neurostimulation compared to those randomized to a control group receiving optimal medical management (OMM) over 1 year. RESTORE is a multicenter, open-label randomized controlled trial. Candidates were assessed for CLBP associated with multifidus dysfunction, with no indication for or history of lumbar spine surgery. Participants were randomized to either restorative neurostimulation with the ReActiv8 system or OMM. The primary endpoint was a comparison of the mean change in the Oswestry Disability Index (ODI) between the treatment and control arms at 1 year, and secondary endpoints included pain (numeric rating scale [NRS]) and health-related quality of life (EuroQol Five-Dimension [EQ-5D-5L]). A total of 203 patients, average age 47 years, and with an average 11-year history of low back pain, were included in the analysis. The primary endpoint was a statistically significant demonstration of a clinically relevant mean improvement in the Oswestry Disability Index (ODI) between restorative neurostimulation and OMM arms: ODI (−19.7 ± 1.4 vs. −2.9 ± 1.4; p < 0.001). Additionally, improvements in both the numeric rating scale (NRS) (−3.6 ± 0.2 vs. −0.6 ± 0.2; p < 0.001) and EuroQol Five-Dimension (EQ-5D-5L) (0.155 ± 0.012 vs. 0.008 ± 0.012; p < 0.001) were statistically and clinically significant in the restorative neurostimulation arm compared to the OMM arm. The RESTORE trial demonstrates that restorative neurostimulation is a safe, reversible, clinically effective, and highly durable option for patients suffering with nonoperative CLBP associated with multifidus dysfunction. This demonstration of treatment superiority over OMM through 1 year is a significant milestone in addressing a major health burden and unmet clinical need. ClinicalTrials.gov Identifier: NCT04803214. Chronic low back pain can occur as a consequence of dysfunction in the key stabilizing muscles of the spine, the multifidi. This type of low back pain is difficult to treat, with many interventions resulting in limited improvement or short-term relief for a significant proportion of patients. Despite this limitation, these approaches still represent the best available care in most practices. Restorative neurostimulation is a technique that stimulates dysfunctional multifidi, overriding muscle inhibition to improve spinal function, reduce disability, and alleviate pain. The hypothesis was that this treatment is appropriate for a specific subset of patients who have failed to respond to best available conservative and interventional care. The goal of this study was to compare the effect of restorative neurostimulation to standard-of-care interventions (optimal medical management) for patients with chronic mechanical low back pain. Patients with an average 11-year history of chronic low back pain and diagnosed with multifidus dysfunction were randomly assigned to either ongoing optimal medical management or restorative neurostimulation. At 1 year, disability, pain, and healthcare-related quality of life were assessed. Patients treated with restorative neurostimulation demonstrated significant improvements in their clinical outcomes compared to those receiving optimal medical management alone. Device-related adverse events were rare, reinforcing the safety profile of this technique. This study demonstrated that without restorative neurostimulation, patients with chronic low back pain and multifidus dysfunction have very few effective options and obtained little clinical benefit from ongoing optimal medical management. Restorative neurostimulation is an important advancement for this difficult-to-treat population.