An implantable restorative-neurostimulator for refractory mechanical chronic low back pain: a randomized sham-controlled clinical trial

An Evidence-Based Consensus for the Use of Neurostimulation for the Treatment of Non-Surgical Low Back Pain: The NEURON Group

Introduction

The use of electrical neuromodulation has often been limited to those with previous back surgery, peripheral neuropathy, and complex regional pain syndrome. Many patients with severe intractable low back pain were thought to be candidates for spinal cord stimulation (SCS), dorsal root ganglion stimulation, or peripheral nerve stimulation but did not meet the criteria. Recently, additional high-level data has supported the use of SCS in non-surgical low back pain (NSLBP), and United States Food and Drug Administration approval has been granted. The American Society of Pain and Neuroscience (ASPN) executive committee realized an unmet need to develop criteria for patient selection for this specific patient population. This is a NEURON project (neuroscience, education, utilization, risk mitigation, optimal outcomes, and neuromodulation), a living guideline for evolving therapies and indications, and is focused on the use of neuraxial stimulation for the treatment of refractory pain.

Methods

After board approval, the society accepted nominees for the project, with an emphasis on experience, publication, research, and diversity. The team created an outline for discussion, chose a grading system based on published guidelines, and created consensus points.

Results

The evidence led to several consensus points to best guide patient selection based on the level of evidence and expert opinion. The results will lead to improved safety and efficacy in implanted patients, and to a new standard for best practices.

Conclusion

The selection of patients for implantation in those who have NSLBP should be based on published literature, best practice, and expert opinion. This NEURON project will allow for regular updates to create a living guideline that will allow for better assimilation of information to improve safety and efficacy going forward.

Application of restorative neurostimulation for chronic mechanical low back pain in an older population with 2-year follow up

INTRODUCTION

Data on the Medicare-aged population show that older patients are major consumers of low back pain (LBP) interventions. An effective approach for patients with mechanical LBP that has been refractory to conservative management is restorative neurostimulation. The efficacy of restorative neurostimulation has been demonstrated in multiple prospective studies, with published follow-up over 4 years, showing a consistent durable effect.

METHODS

To further examine the effect of restorative neurostimulation in an older demographic, data from three clinical studies were aggregated: ReActiv8-B prospectively followed 204 patients, ReActiv8-C study prospectively followed 87 patients and ReActiv8-PMCF prospectively followed 42 patients.Two hundred and sixty-one patients were identified with complete 2-year follow-up and divided into cohorts of equal size based of age quartiles.At 2 years from device activation, patients in either cohort were classified by change in disability (Oswestry Disability Index (ODI)) or change in pain score(NRS/VAS) and assessed as proportion of patients per group at each time point. Additionally, health-related quality of life (HRQoL) (EQ5D-5L) was longitudinally compared with baseline. Differences in proportions were assessed using χ2 and continuous variables by repeated measures analysis of variance.

RESULTS

The oldest quartile (n=65) had a median age of 60 (56-82) years compared with the entire population (n=261) who had a median age of 49 (22-82) years. The completer analysis on patients with 2 years of continuous data showed improvement of a 50% in pain was achieved by 62% and 65% and a 15-point ODI improvement in 48% and 60% in the oldest quartile and entire population, respectively. HRQoL (EuroQol 5-Dimension) improved from baselines of 0.568 and 0.544 to 0.763 and 0.769 in the oldest quartile and entire population respectively. All age quartiles improved statistically and clinically over baseline.

CONCLUSIONS

This aggregate analysis of three independent studies provides insight into the performance of restorative neurostimulation in an older population. Patients derived significant and clinically meaningful benefit in disability, pain and HRQoL. When compared with a similarly indicated cohort of younger patients, there were no statistically or clinically significant differences.

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

INTRODUCTION

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.

METHODS

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]).

RESULTS

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.

CONCLUSION

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.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04803214.

Restorative Neurostimulation of the Multifidus for Chronic Low Back Pain After Prior Lumbar Spinal Surgery: A Single-Center, Consecutive Case Series

OBJECTIVES

Restorative neurostimulation of the lumbar multifidus muscle is a novel therapy for chronic nonspecific low back pain (CLBP). Previous studies have excluded patients with prior lumbar surgery. In this study, we describe outcomes in patients with CLBP after prior lumbar surgery.

MATERIALS AND METHODS

This was a single-center, consecutive case series. The primary outcome measure was the change from baseline numeric rating score (NRS) for low back pain (LBP) and Oswestry Disability Index (ODI) in the first 12 months after treatment. Secondary outcomes were number of patients having minimal clinically important difference (MCID) in NRS and ODI scores, Short Assessment of Patient Satisfaction with their management, relationships between type of prior surgery and outcome, and incidence of adverse events.

RESULTS

The cohort comprised 26 patients (12 men; 14 women; mean age 56 years) who had their lumbar surgery a mean 6.9 years previously; 16 were followed up for 12 months and nine for >six months. One patient (3.6%) had a postoperative infection and required device removal. Both mean ODI and LBP NRS and their 95% CIs decreased serially from baseline 41.8 (36.5-46.5) to 29.3 (22.1-36.6) at six months and 28.1 (21.8-34.4) at 12 months (ODI), and from 6.4 (5.5-7.0), 3.8 (3.1-4.6) and 3.6 (2.5-4.7), respectively, for NRS. Patient levels of satisfaction with treatment were very high. MCIDs were observed in ten patients (40%) who experienced improvement in both their ODI (by >10) and NRS (by >2), and in ten patients who experienced improvement in one of these variables but not the other. The type of prior lumbar surgery did not influence outcomes. There were no device-related complications.

CONCLUSIONS

The early outcome profiles after restorative neurostimulation after lumbar spinal surgery are similar to those reported in patients without prior surgery. Further prospective clinical studies are required to establish the validity of these findings.

An Algorithmic Overview of Advanced Pain Therapies: A Narrative Review

PURPOSE OF REVIEW

Quickly referenceable, streamlined, algorithmic approaches for advanced pain management are lacking for patients, trainees, non-pain specialists, and interventional specialists. This manuscript aims to address this gap by proposing a comprehensive, evidence-based algorithm for managing neuropathic, nociceptive, and cancer-associated pain. Such an algorithm is crucial for pain medicine education, offering a structured approach for patient care refractory to conservative management.

RECENT FINDINGS

A comprehensive literary review with PubMed and regulatory documents from the United States Food and Drug Administration were searched for a variety of interventions. Pain syndromes were categorized into nociceptive and neuropathic pain, and an algorithm was constructed. Serving as an educational tool for patients, trainees, and non-pain specialists, and as an accessible reference for pain specialists, this algorithm bridges knowledge gaps, promotes interdisciplinary collaboration, and streamlines the learning curve for new practitioners. The strength of this algorithm lies in integrating extensive clinical data, emphasizing the latest clinical evidence, and providing a structured decision-making pathway.

A Clinical Care Pathway for Patients With Chronic Mechanical Low Back Pain Having Restorative Neurostimulation for Multifidus Muscle: Description, Patient Compliance, Clinical Outcomes, and Satisfaction in the First Two Years

OBJECTIVES

Restorative neurostimulation for multifidus muscle is a novel therapy for chronic low back pain (CLBP). Optimal outcomes require interdisciplinary follow-up. We describe a clinical care pathway (CPW) for this therapy and report patient compliance, clinical outcomes, and patient satisfaction with the CPW.

MATERIALS AND METHODS

This study aimed to develop, at a single center, a CPW with derivation, practical basis, description, and evolution. Included in the study were audits of 1) patient compliance with attendance over 24 months, 2) medical and paramedical attendance at the clinic, 3) clinical outcomes in terms of reductions in both patient and cohort disability (Oswestry Disability Index, ODI) and CLBP numeric rating score (NRS), and 4) adverse events; and a prospective cross-sectional survey of patient satisfaction with the CPW.

RESULTS

A CPW that involved both preoperative and postoperative education and integrated interdisciplinary care was developed and incorporated into the clinical service with a dedicated clinic. In the two years under study, 172 patients attended the education session, and 92 proceeded to restorative neurostimulation for multifidus muscle therapy; 15 patients who had this therapy before the CPW also were incorporated into the CPW. Patient compliance with the pathway was 88% (95% CI 79%-94%) at 12 months. Attendance at the dedicated CPW clinic by the various subspeciality clinicians ranged between 74% and 100%. There were serial reductions in both ODI (38.9 [95% CI 35.9-41.9] to 24.7 (95% CI 21.1-28.3) and CLBP NRS (6.3 [95% CI 6.0-6.7] to 3.3 (95% 2.7-3.9) after 12 months; 76 of the 99 patients assessable (77%: 95% CI 67%-85%) had a minimally important clinical difference reduction in either ODI or pain NRS, whereas eight were unassessable. Patient satisfaction with the CPW was very high (mean 26.9; median 27, maximum 28).

CONCLUSIONS

The CPW facilitated clinical management and optimized outcomes in patients having restorative neurostimulation. Its design and delivery were very well accepted by patients.

ISSLS Prize in Basic Science 2025: Structural changes of muscle spindles in the multifidus muscle after intervertebral disk injury are resolved by targeted activation of the muscle

PURPOSE

Fibrosis of muscle spindles (sensory organs) in back muscles induced by intervertebral disc (IVD) degeneration could limit transmission of muscle stretch to the sensory receptor and explain the proprioceptive deficits common in back pain. Exercise reduces back muscles fibrosis. This study investigated whether targeted muscle activation via neurostimulation reverses or resolves muscle spindle fibrosis in a model of IVD injury.

METHODS

In eighteen sheep, lumbar (L)1-2 and L3-4 IVD degeneration was induced by partial thickness anulus fibrosis incision and a neurostimulator was implanted. After IVD-degeneration developed for 3 months, neurostimulation of the L2 nerve root activated multifidus in nine randomly selected animals. Multifidus muscle adjacent to the spinous process of L2 (non-stimulated) and L4 (stimulated) was harvested 3 months after activation. Muscle spindles were identified in Van Giessen's-stained sections. Connective tissue spindle capsule thickness, and cross-sectional area (CSA) of the spindle, its periaxial fluid and sensory elements were measured. Immunofluorescence assays evaluated Collagen-I and -III.

RESULTS

Multifidus muscle spindle capsule thickness and Collagen-1 were significantly less in the neurostimulation animals than IVD-injury animals at L4 (stimulated muscle) (P < 0.05), but not L2 (non-stimulated muscle). Spindle capsule thickness was less in lateral than medial regions. CSA of the muscle spindle and sensory elements was less in neurostimulated animals at L4.

CONCLUSION

Targeted multifidus activation reverses or prevents accumulation of connective tissue of the multifidus muscle spindle capsule caused by IVD injury. Reduced fibrosis should maintain sensory function of this important muscle mechanoreceptor and might provide an effective solution to resolve the commonly identified proprioceptive deficits in back pain and maintain healthy spine function.

Musculoskeletal ultrasound-guided needle knife therapy in the treatment of refractory nonspecific low back pain: A single-blind, randomized controlled trial

BACKGROUND

This clinical study aimed to evaluate the Numerical Rating Scale (NRS), Oswestry disability index (ODI), and Japanese Orthopedic Association (JOA) scores at 2, 4, 6, and 12 weeks, and the thickness of the 4th lumbar multifidus under ultrasound at 6 and 12 weeks, using musculoskeletal ultrasound (MU)-guided needle-knife loosening therapy for treating refractory nonspecific low back pain (RNSLBP) compared to usual care, to demonstrate the clinical efficacy of needle knife therapy for RNSLBP. This study used a single-blind, randomized controlled design.

METHODS

A total of 66 patients with RNSLBP who met the inclusion criteria were randomly divided into an observation group and a control group of 33 patients. The observation group underwent MU-guided needle knife release for RNSLBP, whereas the control group underwent low-frequency transcutaneous electrical nerve stimulation therapy, exercise therapy, and oral celecoxib capsules if necessary.

RESULTS

No statistically significant differences were observed in the baseline data (sex, age, body mass index, disease duration, NRS score, ODI score, JOA score, and 4th lumbar multifidus muscle thickness) (P > .05) between the 2 groups, with both groups having flat baseline and comparable indices. After 2, 4, 6, and 12 weeks of treatment, NRS and ODI scores decreased, while JOA scores increased in both groups, with statistically significant differences both within and between the 2 groups. The observation group showed better results than did the control group. The difference in multifidus muscle thickness between the 2 groups was not statistically significant after the final treatment; however, at the 12-week follow-up, the observation group showed significantly greater multifidus muscle thickness than the control group, with a statistically significant difference.

CONCLUSION

This study demonstrated that MU-guided needle knife release effectively treats RNSLBP by reducing pain, improving lumbar spine function, and increasing the multifidus muscle thickness. It is efficient, safe, has a shorter treatment period, and causes fewer adverse reactions.

Systematic Review and Meta-analysis of Stimulation of the Medial Branch of the Lumbar Dorsal Rami for the Treatment of Chronic Low Back Pain

INTRODUCTION

Chronic low back pain (CLBP) is often associated with impaired motor control and degeneration of the lumbar multifidus muscles. Several studies have reported on the utility of multifidus or medial branch stimulation as a treatment. We present a systematic review and meta-analysis of studies reporting on the change in low back pain intensity with multifidus stimulation.

MATERIALS AND METHODS

A comprehensive literature search was conducted from 2010 to 2022 for randomized controlled trials or prospective reports in adults with CLBP, treated with multifidus or medial nerve stimulation through implanted or percutaneous device. Mean change (standard error) in pain intensity was extracted and data synthesized using a mixed effects regression with a random intercept for the study to account for repeated time points.

RESULTS

A total of 419 participants were enrolled in six studies; there were 25 effects (one to six time points per study), with follow-ups ranging from 1.5 to 48 months. The weighted pooled mean effect was a reduction in pain intensity (0-10 scale) of 2.9 units (95% CI: 2.1-3.7). The 95% prediction interval was a reduction in pain intensity of 0.6 to 5.2 units. The estimated probability of a reduction in pain of >two units in a new similar study is 0.84 (0.68-0.98). Meta-regression revealed that a longer follow-up time was associated with greater reductions in pain (0.25 units [0.16-0.34] per six months).

CONCLUSIONS

Medial branch stimulation for the treatment of CLBP shows a high probability of a clinically significant change in pain intensity. Longer duration of stimulation was associated with decreased low back pain intensities.

Reporting guidelines for randomised controlled trial reports of implantable neurostimulation devices: the CONSORT-iNeurostim extension

Background

The Consolidated Standards of Reporting Trials (CONSORT) statement has improved the quality of reporting of randomised trials. Extensions to the CONSORT statement are often needed to address specific issues of trial reporting, including those relevant to particular types of interventions. Methodological and reporting deficiencies in clinical trials of implantable neurostimulation devices are common. The CONSORT-iNeurostim extension is a new reporting guideline for randomised controlled trials evaluating implantable neurostimulation devices.

Methods

CONSORT-iNeurostim was developed using the EQUATOR methodological framework including a literature review and expert consultation to generate an initial list of candidate items. The candidate items were included in a two-round Delphi survey, discussed at an international consensus meeting (42 stakeholders including healthcare professionals, methodologists, journal editors and industry representatives from the United States, United Kingdom, Netherlands and other countries), and refined through a checklist pilot (18 stakeholders).

Findings

The initial extension item list included 49 candidate items relevant to CONSORT-iNeurostim. We received 132 responses in the first round of the Delphi survey and 99 responses in the second round. Participants suggested an additional 20 candidate items for CONSORT-iNeurostim during the first round of the survey, and those achieving initial consensus were discussed at the consensus meeting. The CONSORT-iNeurostim extension includes 7 new checklist items, including one item for reporting the neurostimulation intervention comprising a separate checklist of 14 items.

Interpretation

The CONSORT-iNeurostim extension will promote increased transparency, clarity, and completeness of trial reports of implantable neurostimulation devices. It will assist journal editors, peer-reviewers, and readers to better interpret the appropriateness and generalisability of the methods used and reported outcomes.

Funding

Abbott, Boston Scientific Corp., Mainstay Medical, Medtronic Ltd, Nevro Corp. and Saluda Medical.

Reporting guidelines for protocols of randomised controlled trials of implantable neurostimulation devices: the SPIRIT-iNeurostim extension

Background

The Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) statement has improved the quality of reporting of randomised trial protocols. Extensions to the SPIRIT statement are needed to address specific issues of trial protocol reporting, including those relevant to particular types of interventions. Methodological and reporting deficiencies in protocols of clinical trials of implantable neurostimulation devices are common. The SPIRIT-iNeurostim extension is a new reporting guideline for randomised controlled trial protocols evaluating implantable neurostimulation devices.

Methods

SPIRIT-iNeurostim was developed using the EQUATOR methodological framework including a literature review and expert consultation to generate an initial list of candidate items. The candidate items were included in a two-round Delphi survey, discussed at an international consensus meeting (42 stakeholders including healthcare professionals, methodologists, journal editors and industry representatives from the United States, United Kingdom, Netherlands and other countries), and refined through a checklist pilot (18 stakeholders).

Findings

The initial extension item list included 42 candidate items relevant to SPIRIT-iNeurostim. We received 132 responses in the first round of the Delphi survey and 99 responses in the second round. Participants suggested an additional 14 candidate items for SPIRIT-iNeurostim during the first round of the survey, and those achieving initial consensus were discussed at the consensus meeting. The SPIRIT-iNeurostim extension includes 5 new checklist items, including one item for reporting the neurostimulation intervention comprising a separate checklist of 14 items.

Interpretation

The SPIRIT-iNeurostim extension will help to promote increased transparency, clarity, and completeness of reporting trial protocols evaluating implantable neurostimulation devices. It will assist journal editors, peer-reviewers, and readers to better interpret the appropriateness and generalisability of the methods used for a planned clinical trial.

Funding

Abbott, Boston Scientific Corp., Mainstay Medical, Medtronic Ltd, Nevro Corp., and Saluda Medical.

The Neurostimulation Appropriateness Consensus Committee (NACC)®: Recommendations for Spinal Cord Stimulation Long-Term Outcome Optimization and Salvage Therapy

INTRODUCTION

The International Neuromodulation Society (INS) has recognized a need to establish best practices for optimizing implantable devices and salvage when ideal outcomes are not realized. This group has established the Neurostimulation Appropriateness Consensus Committee (NACC)® to offer guidance on matters needed for both our members and the broader community of those affected by neuromodulation devices.

MATERIALS AND METHODS

The executive committee of the INS nominated faculty for this NACC® publication on the basis of expertise, publications, and career work on the issue. In addition, the faculty was chosen in consideration of diversity and inclusion of different career paths and demographic categories. Once chosen, the faculty was asked to grade current evidence and along with expert opinion create consensus recommendations to address the lapses in information on this topic.

RESULTS

The NACC® group established informative and authoritative recommendations on the salvage and optimization of care for those with indwelling devices. The recommendations are based on evidence and expert opinion and will be expected to evolve as new data are generated for each topic.

CONCLUSIONS

NACC® guidance should be considered for any patient with less-than-optimal outcomes with a stimulation device implanted for treating chronic pain. Consideration should be given to these consensus points to salvage a potentially failed device before explant.

Randomized Placebo-Controlled Trial of 60-Day Percutaneous Peripheral Nerve Stimulation Treatment Indicates Relief of Persistent Postoperative Pain, and Improved Function After Knee Replacement

OBJECTIVES

Total knee arthroplasty (TKA) is an effective surgery for end-stage knee osteoarthritis, but chronic postoperative pain and reduced function affect up to 20% of patients who undergo such surgery. There are limited treatment options, but percutaneous peripheral nerve stimulation (PNS) is a promising nonopioid treatment option for chronic, persistent postoperative pain. The objective of the present study was to evaluate the effect of a 60-day percutaneous PNS treatment in a multicenter, randomized, double-blind, placebo-controlled trial for treating persistent postoperative pain after TKA.

MATERIALS AND METHODS

Patients with postoperative pain after knee replacement were screened for this postmarket, institutional review board-approved, prospectively registered (NCT04341948) trial. Subjects were randomized to receive either active PNS or placebo (sham) stimulation. Subjects and a designated evaluator were blinded to group assignments. Subjects in both groups underwent ultrasound-guided placement of percutaneous fine-wire coiled leads targeting the femoral and sciatic nerves on the leg with postoperative pain. Leads were indwelling for eight weeks, and the primary efficacy outcome compared the proportion of subjects in each group reporting ≥50% reduction in average pain relative to baseline during weeks five to eight. Functional outcomes (6-minute walk test; 6MWT and Western Ontario and McMaster Universities Osteoarthritis Index) and quality of life (Patient Global Impression of Change) also were evaluated at end of treatment (EOT).

RESULTS

A greater proportion of subjects in the PNS groups (60%; 12/20) than in the placebo (sham) group (24%; 5/21) responded with ≥50% pain relief relative to baseline (p = 0.028) during the primary endpoint (weeks 5-8). Subjects in the PNS group also walked a significantly greater distance at EOT than did those in the placebo (sham) group (6MWT; +47% vs -9% change from baseline; p = 0.048, n = 18 vs n = 20 completed the test, respectively). Prospective follow-up to 12 months is ongoing.

CONCLUSIONS

This study provides evidence that percutaneous PNS decreases persistent pain, which leads to improved functional outcomes after TKA at EOT.

Five-Year Longitudinal Follow-Up of Restorative Neurostimulation Shows Durability of Effectiveness in Patients With Refractory Chronic Low Back Pain Associated With Multifidus Muscle Dysfunction

BACKGROUND

Adults with refractory, mechanical chronic low back pain associated with impaired neuromuscular control of the lumbar multifidus muscle have few treatment options that provide long-term clinical benefit. This study hypothesized that restorative neurostimulation, a rehabilitative treatment that activates the lumbar multifidus muscles to overcome underlying dysfunction, is safe and provides relevant and durable clinical benefit to patients with this specific etiology.

MATERIALS AND METHODS

In this prospective five-year longitudinal follow-up of the ReActiv8-B pivotal trial, participants (N = 204) had activity-limiting, moderate-to-severe, refractory, mechanical chronic low back pain, a positive prone instability test result indicating impaired multifidus muscle control, and no indications for spine surgery. Low back pain intensity (10-cm visual analog scale [VAS]), disability (Oswestry Disability Index), and quality of life (EuroQol's "EQ-5D-5L" index) were compared with baseline and following the intent-to-treat principle, with a supporting mixed-effects model for repeated measures that accounted for missing data.

RESULTS

At five years (n = 126), low back pain VAS had improved from 7.3 to 2.4 cm (-4.9; 95% CI, -5.3 to -4.5 cm; p < 0.0001), and 71.8% of participants had a reduction of ≥50%. The Oswestry Disability Index improved from 39.1 to 16.5 (-22.7; 95% CI, -25.4 to -20.8; p < 0.0001), and 61.1% of participants had reduction of ≥20 points. The EQ-5D-5L index improved from 0.585 to 0.807 (0.231; 95% CI, 0.195-0.267; p < 0.0001). Although the mixed-effects model attenuated completed-case results, conclusions and statistical significance were maintained. Of 52 subjects who were on opioids at baseline and had a five-year visit, 46% discontinued, and 23% decreased intake. The safety profile compared favorably with neurostimulator treatments for other types of back pain. No lead migrations were observed.

CONCLUSION

Over a five-year period, restorative neurostimulation provided clinically substantial and durable benefits with a favorable safety profile in patients with refractory chronic low back pain associated with multifidus muscle dysfunction.

CLINICAL TRIAL REGISTRATION

The Clinicaltrials.gov registration number for the study is NCT02577354; registration date: October 15, 2016; principal investigator: Christopher Gilligan, MD, Brigham and Women's Hospital, Boston, MA, USA. The study was conducted in Australia (Broadmeadow, New South Wales; Noosa Heads, Queensland; Welland, South Australia; Clayton, Victoria), Belgium (Sint-Niklaas; Wilrijk), The Netherlands (Rotterdam), UK (Leeds, London, Middlesbrough), and USA (La Jolla, CA; Santa Monica, CA; Aurora, CO; Carmel, IN; Indianapolis, IN; Kansas City, KS; Boston, MA; Royal Oak, MI; Durham, NC; Winston-Salem, NC; Cleveland, OH; Providence, RI; Spartanburg, SC; Spokane, WA; Charleston, WV).

Precision Rehabilitation After Neurostimulation Implantation for Multifidus Dysfunction in Nociceptive Mechanical Chronic Low Back Pain

Chronic low back pain (CLBP) is a debilitating, painful, and costly condition. Implantable neuromuscular electrical stimulation targeting the multifidus musculature is growing as a non-pharmacologic option for patients with recalcitrant nociceptive mechanical CLBP who have failed conservative treatments (including medications and physical therapy) and for whom surgery is not indicated. Properly selecting patients who meet specific criteria (based on historical results from randomized controlled trials), who diligently adhere to implant usage and precisely implement neuromuscular rehabilitation, improve success of significant functional recovery, as well as pain medication reductions. Patients with nociceptive mechanical CLBP who underwent implanted multifidus neurostimulation have been treated by physicians and rehabilitation specialists who have honed their experience working with multifidus neurostimulation. They have collaborated on consensus and evidence-driven guidelines to improve quality outcomes and to assist providers when encountering patients with this device. Physicians and physical therapists together provide precision patient-centric medical management with quality neuromuscular rehabilitation to encourage patients to be experts of both their implants and quality spine motion to help override long-standing multifidus dysfunction related to their CLBP.

Healthcare resource utilization for chronic low back pain among high-utilizers

BACKGROUND

Chronic low back pain is a leading cause of morbidity and is among the largest cost drivers for the healthcare system. Research on healthcare resource utilization of patients with low back pain who are not surgical candidates is limited, and few studies follow individuals who generate high healthcare costs over time.

PURPOSE

This claims study aimed to identify patients with high-impact mechanical, chronic low back pain (CLBP), quantify their low back pain-related health resource utilization, and explore associated patient characteristics. We hypothesize that patients in the top quartile of healthcare resource utilization in the second year after initial diagnosis will continue to generate considerable back pain-related costs in subsequent years.

STUDY DESIGN/SETTING

IBM MarketScan Research Databases from 2009-2019 were retrospectively analyzed.

PATIENT SAMPLE

Adults in the United States with an initial diagnosis of low back pain between 2010 and 2014 who did not have cancer, spine surgery, recent pregnancy, or inflammatory spine conditions, were identified using the International Classification of Diseases (ICD) and Current Procedural Terminology (CPT) codes. To ensure patients had chronic low back pain, it was required that individuals had additional claims with a low back pain diagnosis 6 to 12 and 12 to 24 months after initial diagnosis.

OUTCOME MEASURES

Cost and utilization of inpatient visits, outpatient visits, emergency room visits, pharmacologic and nonpharmacologic treatment options and imaging for chronic low back pain.

METHODS

Annual back pain-related costs and the use of pharmacologic and nonpharmacologic treatments for 5 years were analyzed. Logistic regression was utilized to identify factors associated with persistent high spending.

RESULTS

Of 16,917 individuals who met the criteria for chronic low back pain, 4,229 met the criteria for having high healthcare utilization, defined as being in the top quartile of back pain-related costs in the 12 to 24 months after their initial diagnosis. The mean and median back pain-related cost in the first year after an initial diagnosis was $7,112 (SD $9,670) and $4,405 (Q1 $2,147, Q3 $8,461). Mean and median back pain related costs in the second year were $11,989 (SD $20,316) and $5,935 (Q1 $3,892, Q3 $10,678). Costs continued to be incurred in years 3 to 5 at a reduced rate. The cumulative mean cost for back pain over the 5 years following the initial diagnosis was $31,459 (SD $39,545). The majority of costs were from outpatient services. Almost a quarter of the high utilizers remained in the top quartile of back pain-related costs during years 3 to 5 after the initial diagnosis, and another 19% remained in the top quartile for 2 of the 3 subsequent years. For these two groups combined (42%), the 5-year cumulative mean cost for back pain was $43,818 (SD $48,270). Patient characteristics associated with a higher likelihood of remaining as high utilizers were diabetes, having a greater number of outpatient visits and pharmacologic prescriptions, and lower utilization of imaging services.

CONCLUSION

This is one of the first studies to use an administrative claims database to identify high healthcare resource utilizers among a population of United States individuals with nonsurgical, chronic low back pain and follow their utilization over time. There was a population of individuals who continued to experience high costs 5 years beyond their initial diagnosis, and the majority of individuals continued to seek outpatient services. Further longitudinal claims research that incorporates symptom severity is needed to understand the economic implications of this condition.

Is it possible to generate an additional pleasant and pain-relieving muscle stimulation when using a low-frequency spinal cord stimulation (SCS) for the treatment of lower back pain? Pilot study: A new technique: "MuscleSCS"

OBJECTIVE

The combined use of spinal cord stimulation (SCS) and muscle stimulation, in the treatment of chronic pain, using the same probe, could improve the clinical results. However, this technique has not been established as yet. It was our hypothesis that it is possible to generate muscle stimulation by using low frequencies with SCS electrodes and use it to additionally treat chronic back pain.

METHODS

We generated muscle stimulation in patients with previously implanted SCS electrodes, for the treatment of lower back pain, by using low frequencies (2, 4, 6, and 8 Hz) and different contact combinations of the electrodes. The results were evaluated by using visual inspection (videos), haptic control, surface electromyography (EMG), and sonographic recordings.

RESULTS

This pilot study (17 patients, seven females, age 36-87 years, 11 percutaneous paddle leads, and 6 octrodes) was performed at the Neurosurgical Department of the University of Tuebingen. The most preferred frequencies were 6 Hz (45.5% of percutaneous paddle leads) and 8 Hz (50% of octrodes) at contacts 3&4 or 5&6. The preference of frequencies differed significantly among genders (p = 0.023). Simultaneous EMG and ultrasonic recordings demonstrated the generation of muscle potentials and the stimulation of deeper muscle groups.

CONCLUSION

In this study, it has been shown that with low-frequency SCS stimulation, pleasant and pain-relieving muscle contractions of the lower and upper back can also be generated. This combined method has been coined by us as "MuscleSCS" technique. Clinical trials are necessary to establish the value of this combined technique and its subtypes.

Improvement in post-orthodontic chronic musculoskeletal pain after local anesthetic injections in the trigeminal area: a case series

Orthodontic treatment has been associated with chronic extraoral pain that is often resistant to common treatments such as drugs or physiotherapy, adversely affecting patients' quality of life. In this case series, we discuss the potential impact of orthodontics on chronic cervical spine pain or gonalgia and explore the long-term effect of local anesthetic injections as a possible therapeutic intervention. Six orthodontic patients with chronic cervical spine pain or gonalgia that substantially affected their quality of life were treated with injections of 0.5% procaine into individual lesions and at palpable points of tissue tension in the oral mucosa and extraoral myofascial areas. All patients in this case series reported significant improvement in their chronic pain, with no residual pain recorded at the 6-month follow-up. Injecting local anesthetic at stress points in the oral mucosal and extraoral myofascial regions may be an effective treatment for post-orthodontic neck and knee pain. Further research is required to better understand the potential benefits of this intervention for patients experiencing orthodontic-related musculoskeletal pain.

Rationale and design of an implant procedure and pivotal study to evaluate safety and effectiveness of Medtronic's tibial neuromodulation device

Percutaneous tibial neuromodulation is a medical guideline recommended therapy for treating symptoms of overactive bladder. Stimulation is delivered to the tibial nerve via a thin needle placed percutaneously for 30 min once a week for 12-weeks, and monthly thereafter. Studies have shown that this therapy can effectively relieve symptoms of overactive bladder; however, the frequent office visits present a barrier to patients and can impact therapy effectiveness. To mitigate the burden of frequent clinic visits, small implantable devices are being developed to deliver tibial neuromodulation. These devices are implanted during a single minimally invasive procedure and deliver stimulation intermittently, similar to percutaneous tibial neuromodulation. Here, we describe the implant procedure and design of a pivotal study evaluating the safety and effectiveness for an implantable tibial neuromodulation device. The Evaluation of Implantable Tibial Neuromodulation (TITAN 2) pivotal study is a prospective, multicenter, investigational device exemption study being conducted at up to 30 sites in the United States and enrolling subjects with symptoms of overactive bladder.

Sham controls in device trials for chronic pain - tricky in practice-a review article

Background

Chronic pain affects one in four people and this figure is likely to increase further in line with an ageing population. Efforts to evaluate nonpharmacological interventions to support this patient population have become a priority for pain research. For device trials, the use of a sham control can add to the scientific validity and quality of a study. However, only a small proportion of pain trials include a sham control, and many are of poor quality. To facilitate the conduct of high-quality trials there is a need for a comprehensive overview to guide researchers within this area. The objective of this review was to synthesise the published data to address this need.

Methods

We identified studies that considered the evaluation, design, and conduct of sham-controlled trials in chronic pain by searching MEDLINE, CINAHL and Science Direct to November 2022. Studies that included sufficient content to inform the conduct/design of future research were included. An inductive thematic analysis approach was used to identify themes that require consideration when conducting sham-controlled trials. These are presented as a narrative review.

Results

37 articles were included. Identified themes related to the type of sham device, sham design, bias, study population and ethics.

Conclusions

To conduct good quality research the challenges surrounding the use of sham interventions need to be better considered. We highlight salient issues and provide recommendations for the conduct and reporting of sham-controlled device trials in chronic pain.

Restorative neurostimulation for chronic mechanical low back pain - Three year results from the United Kingdom post market clinical follow-up registry

Introduction

Mechanical chronic low back pain is often associated with impaired neuromuscular control of the lumbar multifidus muscles, the most important stabilizers of the lumbar spine. Restorative neurostimulation is a modality for the treatment for this specific subset of patients aimed to facilitate restoration of neuromuscular control by bilateral stimulation of the L2 medial branches. Evidence from both prospective and randomised clinical trials to date has demonstrated substantial improvements in clinical outcomes such as pain, disability and health-related quality of life.

Methods

This study is an open label prospective follow-up for the treatment of chronic mechanical low back pain of nociceptive origin with restorative neurostimulation. Patients completed assessments for pain, disability and health-related quality of life. Outcomes were collected at 45, 90 and 180 days, and 1, 2 and 3 years after the activation visit.

Results

Forty-two patients were implanted with the device and 33 (79%) were available at the 3-year appointment. Patients in this cohort presented with severe chronic low back pain (NRS = 7.0 ± 0.2) and severe disability (ODI 46.6 ± 12.0). The health-related quality of life was also severely impacted at baseline (EQ-5D 0.426 ± 0.061). Changes in pain, disability and quality of life at three-year follow-up demonstrated a statistically significant improvement between baseline and 1, 2 and 3 years. After 3 years of therapy, average NRS scores had reduced to 2.7± 0.3 and mean ODI score to 26.0 ± 3.1 while EQ-5D-5L index improved to 0.707 ± 0.036.

Conclusions

The ongoing follow-up of this post market cohort continues to demonstrate that restorative neurostimulation provides a statistically significant, clinically meaningful and durable response across pain, disability and quality-of life scores for patients suffering chronic mechanical low back pain that has been refractory to conventional management.

Trial Registration

ClinicalTrials.gov Identifier: NCT01985230.

International Society for the Advancement of Spine Surgery Statement: Restorative Neurostimulation for Chronic Mechanical Low Back Pain Resulting From Neuromuscular Instability

This International Society for the Advancement of Spine Surgery statement has been generated to respond to growing requests for background, supporting literature and evidence, and proper coding for restorative neurostimulation for chronic low back pain. Chronic low back pain describes the diverse experience of a significant proportion of the population. Conservative management of these patients remains the predominant care pathway, but for many patients, symptom relief is poor. The application of new techniques in patients who have exhausted traditional care paradigms should be undertaken with a detailed understanding of the pathology being treated, the mechanisms involved, and the data supporting efficacy. This statement on restorative neurostimulation places this technology in the context of the current understanding of the etiology of mechanical low back pain and the currently available evidence for this technique. In an appropriately selected cohort with a specific subset of chronic low back pain symptoms, this technique may provide benefit to payers and patients.

Treatment of Refractory Low Back Pain Using Passive Recharge Burst in Patients Without Options for Corrective Surgery: Findings and Results From the DISTINCT Study, a Prospective Randomized Multicenter Controlled Trial

OBJECTIVE

Spinal cord stimulation (SCS) is effective for relieving chronic intractable pain conditions. The Dorsal spInal cord STImulatioN vs mediCal management for the Treatment of low back pain study evaluates the effectiveness of SCS compared with conventional medical management (CMM) in the treatment of chronic low back pain in patients who had not undergone and were not candidates for lumbar spine surgery.

METHODS AND MATERIALS

Patients were randomized to passive recharge burst therapy (n = 162) or CMM (n = 107). They reported severe pain and disability for more than a decade and had failed a multitude of therapies. Common diagnoses included degenerative disc disease, spondylosis, stenosis, and scoliosis-yet not to a degree amenable to surgery. The six-month primary end point compared responder rates, defined by a 50% reduction in pain. Hierarchical analyses of seven secondary end points were performed in the following order: composite responder rate (numerical rating scale [NRS] or Oswestry Disability Index [ODI]), NRS, ODI, Pain Catastrophizing Scale responder rate, Patient Global Impression of Change (PGIC) responder rate, and Patient-Reported Outcome Measure Information System-29 in pain interference and physical function.

RESULTS

Intention-to-treat analysis showed a significant difference in pain responders on NRS between SCS (72.6%) and CMM (7.1%) arms (p < 0.0001). Of note, 85.2% of those who received six months of therapy responded on NRS compared with 6.2% of those with CMM (p < 0.0001). All secondary end points indicated the superiority of burst therapy over CMM. A composite measure on function or pain relief showed 91% of subjects with SCS improved, compared with 16% of subjects with CMM. A substantial improvement of 30 points was observed on ODI compared with a

CONCLUSIONS

This study found substantial improvement at six months in back pain, back pain-related disability, pain-related emotional suffering, PGIC, pain interference, and physical function in a population with severe, debilitating back pain for more than a decade. These improvements were reported in conjunction with reduced opioid use, injection, and ablation therapy.

CLINICAL TRIAL REGISTRATION

The Clinicaltrials.gov registration number for the study is NCT04479787.

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Key Words

• composite outcomes
• persistent spinal pain syndrome
• refractory chronic low back pain
• spinal cord stimulation

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MESH Headings

• Humans
• Low Back Pain/therapy
• Low Back Pain/psychology
• Treatment Outcome
• Prospective Studies
• Back Pain
• Spinal Cord Stimulation/methods
• Chronic Pain/diagnosis
• Chronic Pain/therapy

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Grants

• K08 CA228039 NCI NIH HHS

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Affiliation(s)

Timothy Deer The Spine and Nerve Center of the Virginias, Charleston, WV, USA
Christopher Gilligan Brigham & Women's Hospital, Boston, MA, USA
Steven Falowski Center for Interventional Pain & Spine, Lancaster, PA, USA
Mehul Desai International Spine, Pain & Performance Center, Washington, DC, USA
Julie Pilitsis Florida Atlantic University, FL, USA
Jessica Jameson Axis Spine Center, ID, USA
Susan Moeschler Mayo Clinic, Rochester, NY, USA
Robert Heros Spinal Diagnostics, OR, USA
Edward Tavel Clinical Trials of South Carolina, Charleston, SC, USA
Anne Christopher Saint Louis Pain Consultants, Chesterfield, MO, USA
Denis Patterson Nevada Advanced Pain Specialists, Reno, NV, USA
Sayed Wahezi Montefiore Medical Center-Waters Place, New York, NY, USA
Jacqueline Weisbein Napa Valley Orthopedic Medical Group, Napa, CA, USA
Ajay Antony The Orthopaedic Institute, FL, USA
Robert Funk Indiana Spine Group, IN, USA
Mohab Ibrahim Banner University Medical Center Tucson Campus, Tucson, AZ, USA
Chi Lim Carolina Orthopaedic & Neurosurgical Associates, SC, USA
Derron Wilson Goodman Campbell Brain & Spine, IN, USA
Michael Fishell Advanced Pain Care, NV, USA
Keith Scarfo Rhode Island Hospital, Providence, RI, USA
David Dickerson Northshore University HealthSystem, Chicago, IL, USA
Edward Braun Kansas University Medical Center, KS, USA
Patrick Buchanan Spanish Hills Interventional Pain Specialists, Camarillo, CA, USA
Robert M Levy Anesthesia Pain Care Consultants-Tamarac
Nathan Miller Coastal Pain & Spinal Diagnostics Medical Group, Carlsbad, CA, USA
Jonathan Duncan Burkhart Research Institute for Orthopaedics, San Antonio, TX, USA
Jijun Xu The Cleveland Clinic Foundation, OH, USA
Kenneth Candido Chicago Anesthesia Associates, SC, Chicago, IL, USA
Scott Kreiner Barrow Brain & Spine-Ahwatukee, Phoenix, AZ, USA
Marie E Fahey Abbott Labs, Austin, TX, USA
James Yue Connecticut Orthopaedics, CT, USA

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Peripheral Nerve Stimulation for Low Back Pain: A Systematic Review

PURPOSE OF REVIEW

Low back pain (LBP) is a prevalent condition that is associated with diminished physical function, poor mental health outcomes, and reduced quality of life. Peripheral nerve stimulation (PNS) is an emerging modality that has been utilized to treat LBP. The primary objective of this systematic review is to appraise the level of evidence on the efficacy of PNS for treatment of LBP.

RECENT FINDINGS

Twenty-nine articles were included in this systematic review, consisting of 828 total participants utilizing PNS as the primary modality for LBP and 173 participants using PNS as salvage or adjunctive therapy for LBP after SCS placement. Different modalities of PNS therapy were reported across studies, including conventional PNS systems stimulating the lumbar medial branch nerves, peripheral nerve field stimulation (PNFS), and restorative neuromuscular stimulation of the multifidus muscles. All studies consistently reported positive modest to moderate improvement in pain intensity with PNS therapy when comparing baseline pain intensity to each study's respective primary follow-up period. There was a very low GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) quality of evidence supporting this finding. Inconsistency was present in some comparative studies that demonstrated no difference between PNS therapy versus control cohorts (sham or SCS therapy alone), which therefore highlighted the potential for placebo effect. This systematic review highlights that PNS, PNFS, and neuromuscular stimulation may provide modest to moderate pain relief in patients with LBP, although evidence is currently limited due to risk of bias, clinical and methodological heterogeneity, and inconsistency in data.

ReActiv8 Stimulation Therapy vs. Optimal Medical Management: A Randomized Controlled Trial for the Treatment of Intractable Mechanical Chronic Low Back Pain (RESTORE Trial Protocol)

INTRODUCTION

Chronic low back pain (CLBP) is the leading cause of years lived with disability globally. The role of restorative neurostimulation in the treatment of patients with refractory mechanical CLBP and multifidus muscle dysfunction has been established in one randomized controlled trial (RCT) and several clinical studies that demonstrated both safety and clinical benefit. This post-market trial provides a direct comparison to optimized medical management to test the hypothesis that the addition of restorative neurostimulation to current care paradigms results in significant improvements in back pain-related disability.

METHODS AND ANALYSIS

This trial will include people who have reported significant levels of back pain and back pain-related disability with symptoms that have persisted for longer than 6 months prior to enrollment and resulted in pain on most days in the 12 months prior to enrollment. Eligible patients will be randomized to either optimal medical management or optimal medical management plus ReActiv8® restorative neurostimulation therapy. Patient-reported outcomes will be collected at regular intervals out to the 1-year primary endpoint, at which time the patients in the control arm will be offered implantation with the ReActiv8 system. Assessment of each group will continue for an additional year.

ETHICS AND DISSEMINATION

The RESTORE trial follows the principles of the Declaration of Helsinki. The WCG IRB acts as the Central Institutional Review Board (IRB) for most sites and some sites will receive local IRB approval prior to enrollment of patients. Each IRB assessed the protocol and related documentation. The protocol complies with Good Clinical Practice (GCP). All patients provide written informed consent to participate in the trial.

PROTOCOL VERSION

Version C, 07 Sep 2022.

CLINICALTRIALS

gov registration number. NCT04803214 registered March 17, 2021.

Safety and efficacy of 650 nm invasive laser acupuncture on non-specific chronic low back pain: A protocol for a multicenter randomized placebo-controlled trial

Background

We aim to obtain clinical trial data regarding the safety, efficacy, and usefulness of invasive laser acupuncture (ILA) for non-specific chronic low back pain (NSCLBP) through a randomized placebo-controlled trial.

Methods

Our clinical trial will be an assessor- and patient-blinded, prospective, parallel-arm, multi-center, randomized placebo-controlled clinical trial. One hundred and six participants with NSCLBP will be allocated evenly to the 650 ILA or control group. All participants will receive education on exercise and self-management. The 650 ILA group will undergo 650 nm ILA for 10 min, and the control group will undergo sham ILA for 10 min per visit, twice a week for 4 weeks, at bilateral GB30, BL23, BL24, and BL25. The primary outcome will be the proportion of responders (≥30% reduction in pain visual analogue scale [VAS] without increased use of painkillers) at 3 days after the intervention ends. The secondary outcomes will include changes in the scores of the VAS, European Quality of Life Five Dimension Five Level scale, and Korean version of the Oswestry Disability Index at 3 days after the intervention ends and 8 weeks after the intervention ends.

Discussions

The results of our study will provide clinical evidence concerning the safety and efficacy of 650 nm ILA for the management of NSCLBP.

Clinical trial registration

https://cris.nih.go.kr/cris/search/detailSearch.do?search_lang=E&focus=reset_12&search_page=M&pageSize=10&page=undefined&seq=21591&status=5&seq_group=21591, identifier KCT0007167.

The American Society of Pain and Neuroscience (ASPN) Evidence-Based Clinical Guideline of Interventional Treatments for Low Back Pain

Introduction

Painful lumbar spinal disorders represent a leading cause of disability in the US and worldwide. Interventional treatments for lumbar disorders are an effective treatment for the pain and disability from low back pain. Although many established and emerging interventional procedures are currently available, there exists a need for a defined guideline for their appropriateness, effectiveness, and safety.

Objective

The ASPN Back Guideline was developed to provide clinicians the most comprehensive review of interventional treatments for lower back disorders. Clinicians should utilize the ASPN Back Guideline to evaluate the quality of the literature, safety, and efficacy of interventional treatments for lower back disorders.

Methods

The American Society of Pain and Neuroscience (ASPN) identified an educational need for a comprehensive clinical guideline to provide evidence-based recommendations. Experts from the fields of Anesthesiology, Physiatry, Neurology, Neurosurgery, Radiology, and Pain Psychology developed the ASPN Back Guideline. The world literature in English was searched using Medline, EMBASE, Cochrane CENTRAL, BioMed Central, Web of Science, Google Scholar, PubMed, Current Contents Connect, Scopus, and meeting abstracts to identify and compile the evidence (per section) for back-related pain. Search words were selected based upon the section represented. Identified peer-reviewed literature was critiqued using United States Preventive Services Task Force (USPSTF) criteria and consensus points are presented.

Results

After a comprehensive review and analysis of the available evidence, the ASPN Back Guideline group was able to rate the literature and provide therapy grades to each of the most commonly available interventional treatments for low back pain.

Conclusion

The ASPN Back Guideline represents the first comprehensive analysis and grading of the existing and emerging interventional treatments available for low back pain. This will be a living document which will be periodically updated to the current standard of care based on the available evidence within peer-reviewed literature.

Restorative Neurostimulation: A Clinical Guide for Therapy Adoption

In this review, we present a comprehensive clinical approach to restorative neurostimulation, a novel form of stimulation for refractory chronic mechanical low back pain, targeting impaired neuromuscular control and degeneration of the multifidus muscle. We focus on patient identification, technique guidance, and review of the scientific background and clinical evidence. As our understanding of back pain grows, there is clear evidence that impaired neuromuscular control and consequent degeneration of the multifidus muscle contribute to mechanical low back pain development and maintenance. We provide clinical guidance regarding an implantable restorative neurostimulation system that targets impaired neuromuscular control. Supported by results from a randomized, active-sham-controlled clinical trial with long-term follow-up, we provide clinicians with a comprehensive overview and practical clinical guidance for the adoption of this therapy modality.

60-Day PNS Treatment May Improve Identification of Delayed Responders and Delayed Non-Responders to Neurostimulation for Pain Relief

Objective

Conventional neurostimulation typically involves a brief (eg, ≤10-day) trial to assess presumed effectiveness prior to permanent implantation. Low trial conversion rates and high explant rates due to inadequate pain relief highlight the need for improved patient identification strategies. The development of a 60-day percutaneous peripheral nerve stimulation (PNS) system enables evaluation of outcomes following an extended temporary treatment period of up to 60 days, that may obviate or validate the need for permanent implant. The present study provides the first real-world evidence regarding patient response throughout a 60-day PNS treatment period.

Methods

Anonymized data listings were compiled from patients who underwent implantation of temporary percutaneous leads and opted-in to provide real-world data to the device manufacturer during routine interactions with device representatives throughout the 60-day treatment.

Results

Overall, 30% (222/747) of patients were early responders (≥50% pain relief throughout treatment). Another 31% (231/747) of patients initially presented as non-responders but surpassed 50% pain relief by the end of treatment. Conversely, 32% (239/747) of patients were non-responders throughout treatment. An additional 7% (55/747) of patients initially presented as responders but fell below 50% relief by the end of the treatment period.

Conclusion

An extended, 60-day PNS treatment may help identify delayed responders, providing the opportunity for sustained relief and improving access to effective PNS treatment. Compared to a conventionally short trial of ≤10 days, a longer 60-day PNS treatment may also help reduce explant rates by identifying delayed non-responders unlikely to benefit long-term. These scenarios support the importance of an extended 60-day temporary PNS stimulation period to help inform stepwise treatment strategies that may optimize outcomes and cost-effectiveness.

Non-Spinal Neuromodulation of the Lumbar Medial Branch Nerve for Chronic Axial Low Back Pain: A Narrative Review

Chronic low back pain remains highly prevalent, costly, and the leading cause of disability worldwide. Symptoms are complex and treatment involves an interdisciplinary approach. Due to diverse anatomical etiologies, treatment outcomes with interventional options are highly variable. A novel approach to treating chronic axial low back pain entails the use of peripheral nerve stimulation to the lumbar medial branch nerve, and this review examines the clinical data of the two different, commercially available, non-spinal neuromodulation systems. This review provides the clinician a succinct narrative that presents up-to-date data objectively. Our review found ten clinical studies, including one report of two cases, six prospective studies, and three randomized clinical trials published to date. Currently, there are different proposed mechanisms of action to address chronic axial low back pain with different implantation techniques. Evidence suggests that peripheral nerve stimulation of the lumbar medial branch nerve may be effective in improving pain and function in patients with chronic axial low back pain symptoms at short and long term follow up, with good safety profiles. Further long-term data is needed to consider this intervention earlier in the pain treatment algorithm, but initial data are promising.

Restorative Neurostimulation for Chronic Mechanical Low Back Pain: Results from a Prospective Multi-centre Longitudinal Cohort

INTRODUCTION

Low back pain impacts most people throughout the course of their lives and contributes significantly to the global burden of disease. In some patients, symptoms resolve with little intervention, while others are amenable to surgical intervention, some cases are intractable to current care paradigms. Restorative neurostimulation is an emerging therapy for chronic mechanical low back pain.

METHODS

We conducted a prospective post-market follow-up of 42 patients treated for longstanding chronic mechanical low back pain with restorative neurostimulation. Patients were followed up at 45, 90, and 180 days and 1 and 2 years following activation of the device. Pain, disability, and health-related quality of life were recorded.

RESULTS

Among the 37 patients completing 2-year follow-up, numerical rating scale (NRS) pain scores improved from 7.0 ± 0.2 to 3.5 ± 0.3 (p < 0.001), Oswestry Disability Index (ODI) scores improved from 46.2 ± 2.2 to 29.2 ± 3.1 (p < 0.001), and health-related quality of life (measured by the EuroQol 5-Dimension 5-Level questionnaire-EQ-5D-5L) improved from 0.426 ± 0.035 to 0.675 ± 0.030 (p < 0.001). Additionally, 57% of patients experienced a greater than 50% reduction in pain, and 51% of patients benefited by a greater than 15-point reduction in ODI, both substantial improvements.

CONCLUSION

This real-world sample of patients shows that restorative neurostimulation can provide substantial and durable benefit to a cohort of patients that have traditionally had few reliable treatment options. Our findings support the continued used of this therapy in well-selected patients.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01985230.

Durability of the Therapeutic Effect of Restorative Neurostimulation for Refractory Chronic Low Back Pain

Objectives

The purpose of the ongoing follow‐up of ReActiv8‐A clinical trial is to document the longitudinal benefits of episodic stimulation of the dorsal ramus medial branch and consequent contraction of the lumbar multifidus in patients with refractory mechanical chronic low back pain (CLBP). We report the four‐year outcomes of this trial.

Materials and Methods

ReActiv8‐A is a prospective, single‐arm trial performed at nine sites in the United Kingdom, Belgium, and Australia. Eligible patients had disabling CLBP (low back pain Numeric Rating Scale [NRS] ≥6; Oswestry Disability Index [ODI] ≥25), no indications for spine surgery or spinal cord stimulation, and failed conventional management including at least physical therapy and medications for low back pain. Fourteen days postimplantation, stimulation parameters were programmed to elicit strong, smooth contractions of the multifidus, and participants were given instructions to activate the device for 30‐min stimulation‐sessions twice daily. Annual follow‐up through four years included collection of NRS, ODI, and European Quality of Life Score on Five Dimensions (EQ‐5D). Background on mechanisms, trial design, and one‐year outcomes were previously described.

Results

At baseline (N = 53) (mean ± SD) age was 44 ± 10 years; duration of back pain was 14 ± 11 years, NRS was 6.8 ± 0.8, ODI 44.9 ± 10.1, and EQ‐5D 0.434 ± 0.185. Mean improvements from baseline were statistically significant (p < 0.001) and clinically meaningful for all follow‐ups. Patients completing year 4 follow‐up, reported mean (±standard error of the mean) NRS: 3.2 ± 0.4, ODI: 23.0 ± 3.2, and EQ‐5D: 0.721 ± 0.035. Moreover, 73% of participants had a clinically meaningful improvement of ≥2 points on NRS, 76% of ≥10 points on ODI, and 62.5% had a clinically meaningful improvement in both NRS and ODI and 97% were (very) satisfied with treatment.

Conclusions

In participants with disabling intractable CLBP who receive long‐term restorative neurostimulation, treatment satisfaction remains high and improvements in pain, disability, and quality‐of‐life are clinically meaningful and durable through four years.