Chronic Low Back Pain: Restoration of Dynamic Stability

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.

Effect of exercise and manual therapy or kinesiotaping on sEMG and pain perception in chronic low back pain: a randomized trial

The importance of incorporating lumbo-pelvic stability core and controlling motor exercises in patients with chronic low back pain (CLBP) reinforces the use of strategies to improve biopsychosocial beliefs by reducing biomedical postulations. However, clinical practice guidelines recommend multimodal approaches incorporating exercise and manual therapy (MT), and instead reject the application of kinesiotape (KT) in isolation. Therefore, the objectives of this study were to analyze the effects of 12 weeks of exercises combined with MT or KT on perceived low back pain using the visual analog scale (VAS) and muscle electric activity measured with electromyography (EMG) of the rectus abdominis and multifidus in CLBP (mild disability) and to explore the relationship between the rectus abdominis and multifidus ratios and pain perception after intervention. A blinded, 12-week randomized controlled trial (RCT) was carried out, involving three parallel groups of patients with CLBP. The study was registered at Clinicaltrial.gov and assigned the identification number NCT05544890 (19/09/22). The trial underwent an intention-to-treat analysis. The primary outcome revealed a multimodal treatment program supplemented by additional therapies such as MT and KT, resulting in significant reductions in perceived low back pain. The subjective assessment of individuals with CLBP indicated no discernible distinction between exclusive core stability exercises and control-motor training when combined with MT or KT. Notably, our findings demonstrated positive alterations in both the mean and peak EMG values of the right rectus abdominis in the exercise group, suggesting a beneficial impact on muscle activation. This study focused on assessing the activation levels of the trunk musculature, specifically the rectus abdominis (RA) and multifidus (MF), in individuals with CLBP exhibiting mild disability according to the Oswestry Disability Index. Importantly, improvements in the VAS values were observed independently of changes in muscle electrical activity.

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.

Multifidus dysfunction and restorative neurostimulation: a scoping review

OBJECTIVE

Chronic low back pain (CLBP) is multifactorial in nature, with recent research highlighting the role of multifidus dysfunction in a subset of nonspecific CLBP. This review aimed to provide a foundational reference that elucidates the pathophysiological cascade of multifidus dysfunction, how it contrasts with other CLBP etiologies and the role of restorative neurostimulation.

METHODS

A scoping review of the literature.

RESULTS

In total, 194 articles were included, and findings were presented to highlight emerging principles related to multifidus dysfunction and restorative neurostimulation. Multifidus dysfunction is diagnosed by a history of mechanical, axial, nociceptive CLBP and exam demonstrating functional lumbar instability, which differs from other structural etiologies. Diagnostic images may be used to grade multifidus atrophy and assess other structural pathologies. While various treatments exist for CLBP, restorative neurostimulation distinguishes itself from traditional neurostimulation in a way that treats a different etiology, targets a different anatomical site, and has a distinctive mechanism of action.

CONCLUSIONS

Multifidus dysfunction has been proposed to result from loss of neuromuscular control, which may manifest clinically as muscle inhibition resulting in altered movement patterns. Over time, this cycle may result in potential atrophy, degeneration and CLBP. Restorative neurostimulation, a novel implantable neurostimulator system, stimulates the efferent lumbar medial branch nerve to elicit repetitive multifidus contractions. This intervention aims to interrupt the cycle of dysfunction and normalize multifidus activity incrementally, potentially restoring neuromuscular control. Restorative neurostimulation has been shown to reduce pain and disability in CLBP, improve quality of life and reduce health care expenditures.

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.

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.

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

ABSTRACT

Chronic low back pain can be caused by impaired control and degeneration of the multifidus muscles and consequent functional instability of the lumbar spine. Available treatment options have limited effectiveness and prognosis is unfavorable. We conducted an international randomized, double-blind, sham-controlled trial at 26 multidisciplinary centers to determine safety and efficacy of an implantable, restorative neurostimulator designed to restore multifidus neuromuscular control and facilitate relief of symptoms (clinicaltrials.gov identifier: NCT02577354). Two hundred four eligible participants with refractory mechanical (musculoskeletal) chronic LBP and a positive prone instability test indicating impaired multifidus control were implanted and randomized to therapeutic (N = 102) or low-level sham (N = 102) stimulation of the medial branch of the dorsal ramus nerve (multifidus nerve supply) for 30 minutes twice daily. The primary endpoint was the comparison of responder proportions (≥30% relief on the LBP visual analogue scale without analgesics increase) at 120 days. After the primary endpoint assessment, participants in the sham-control group switched to therapeutic stimulation and the combined cohort was assessed through 1 year for long-term outcomes and adverse events. The primary endpoint was inconclusive in terms of treatment superiority (57.1% vs 46.6%; difference: 10.4%; 95% confidence interval, -3.3% to 24.1%, P = 0.138). Prespecified secondary outcomes and analyses were consistent with a modest but clinically meaningful treatment benefit at 120 days. Improvements from baseline, which continued to accrue in all outcome measures after conclusion of the double-blind phase, were clinically important at 1 year. The incidence of serious procedure- or device-related adverse events (3.9%) compared favorably with other neuromodulation therapies for chronic pain.

Slacklining as therapy to address non-specific low back pain in the presence of multifidus arthrogenic muscle inhibition

Low back pain (LBP) represents the most prevalent, problematic and painful of musculoskeletal conditions that affects both the individual and society with health and economic concerns. LBP is a heterogeneous condition with multiple diagnoses and causes. In the absence of consensus definitions, partly because of terminology inconsistency, it is further referred to as non-specific LBP (NSLBP). In NSLBP patients, the lumbar multifidus (MF), a key stabilizing muscle, has a depleted role due to recognized myocellular lipid infiltration and wasting, with the potential primary cause hypothesized as arthrogenic muscle inhibition (AMI). This link between AMI and NSLBP continues to gain increasing recognition. To date there is no 'gold standard' or consensus treatment to alleviate symptoms and disability due to NSLBP, though the advocated interventions are numerous, with marked variations in costs and levels of supportive evidence. However, there is consensus that NSLBP management be cost-effective, self-administered, educational, exercise-based, and use multi-modal and multi-disciplinary approaches. An adjuvant therapy fulfilling these consensus criteria is 'slacklining', within an overall rehabilitation program. Slacklining, the neuromechanical action of balance retention on a tightened band, induces strategic indirect-involuntary therapeutic muscle activation exercise incorporating spinal motor control. Though several models have been proposed, understanding slacklining's neuro-motor mechanism of action remains incomplete. Slacklining has demonstrated clinical effects to overcome AMI in peripheral joints, particularly the knee, and is reported in clinical case-studies as showing promising results in reducing NSLBP related to MF deficiency induced through AMI (MF-AMI). Therefore, this paper aims to: rationalize why and how adjuvant, slacklining therapeutic exercise may positively affect patients with NSLBP, due to MF-AMI induced depletion of spinal stabilization; considers current understandings and interventions for NSLBP, including the contributing role of MF-AMI; and details the reasons why slacklining could be considered as a potential adjuvant intervention for NSLBP through its indirect-involuntary action. This action is hypothesized to occur through an over-ride or inhibition of central down-regulatory induced muscle insufficiency, present due to AMI. This subsequently allows neuroplasticity, normal neuro-motor sequencing and muscle re-activation, which facilitates innate advantageous spinal stabilization. This in-turn addresses and reduces NSLBP, its concurrent symptoms and functional disability. This process is hypothesized to occur through four neuro-physiological processing pathways: finite neural delay; movement-control phenotypes; inhibition of action and the innate primordial imperative; and accentuated corticospinal drive. Further research is recommended to investigate these hypotheses and the effect of slacklining as an adjuvant therapy in cohort and control studies of NSLBP populations.

Development and Description of a New Multifidus-Sparing Radiofrequency Neurotomy Technique for Facet Joint Pain

INTRODUCTION

The technique of radiofrequency neurotomy (RFN) of the facet joints has been used for decades to treat persistent low back pain to good effect in carefully selected patients. Traditionally, the target is the medial branches of the dorsal root supplying the facet joint. An alternative denervation target is the facet joint capsule. Capsule-targeting techniques may spare the multifidus muscle, a possible unintended target of traditional RFN that is thought to be important in recovering from low back pain, and have shown promising results.

METHODS

A modified RFN technique that targets the capsule and spares the multifidus (multifidus-sparing RFN) is described here, along with a brief report of its application in patients with symptomatic facet joint low back pain as compared to traditional medial branch RFN (MBRF).

RESULTS

Over a 2-year period, a total of 401 initial multifidus-sparing RFN and 94 initial MBRF procedures were performed on patients attending a multidisciplinary pain clinic. The proportion of repeat procedures was similar: 28.4% of multifidus-sparing procedures and 23.4% of MBRF procedures. The median repeat interval was 12 months for both groups and interquartile range was 10 months (8-18 months) for multifidus-sparing RFN and 4 months (11-15 months) for MBRF. Effectiveness and safety profiles appear to be similar, although limited, retrospective outcome information prevented robust analysis.

CONCLUSION

Multifidus-sparing RFN represents an intriguing technique to denervate the facet joint pain generator while maintaining normal multifidus function. Further study is warranted, particularly in order to identify the appropriate patient criteria and long-term outcomes.

A Review of Peripheral Nerve Stimulation Techniques Targeting the Medial Branches of the Lumbar Dorsal Rami in the Treatment of Chronic Low Back Pain

OBJECTIVES

The lumbar medial branch nerve has historically been a focus for ablative techniques in the treatment of chronic low back pain (CLBP) of facetogenic origin. Recent developments in the field of neuromodulation have been employed to target these nerves for analgesia and/or functional restoration in broader populations of CLBP patients. The objective of this article was to provide an introductory review of procedural techniques and devices employed for peripheral nerve stimulation (PNS) of the lumbar medial branch of the dorsal ramus for the treatment of CLBP.

METHODS

A literature search via PubMed.gov was performed through September 2019 with key words focusing on peripheral nerve stimulation for chronic low back pain. This was refined to include only those articles that focused specifically on stimulation of the lumbar medial branch of the dorsal ramus. References within selected articles and unpublished data currently in the peer review process were also utilized.

RESULTS

Ninety articles from PubMed.gov were obtained. Two approaches to PNS of the medial branch of the dorsal ramus were identified.

CONCLUSIONS

Our review of the current literature regarding techniques for neuromodulation of the medial branch of the dorsal ramus revealed two dominant methods: a temporarily implanted percutaneous coiled-lead approach and a permanently implanted system. The two techniques share some similarities, such as targeting the medial branch of the dorsal ramus, and also have some differences, such as indwelling time, stimulation parameters, duration of treatment, image guidance, and degrees of invasiveness, but they are both demonstrating promising results in clinical trials.

Percutaneous Peripheral Nerve Stimulation for Pain Reduction and Improvements in Functional Outcomes in Chronic Low Back Pain

Chronic low back pain represents one of the most common sources of disability and a significant healthcare burden for the U.S. military. Present treatments for chronic back pain are often ineffective, poorly tolerated, invasive, destructive, and/or associated with complications and lead to the progression to invasive surgical procedures. There have been multiple calls for the development of a minimally invasive system that is effective without the risks or complications of existing surgical therapies, which could prevent the need for surgery and the recurrence of pain. The goal of this study was to evaluate a novel, minimally invasive approach using a percutaneous peripheral nerve stimulation (PNS) system designed to provide pain relief without surgery, to reduce complications, and provide a less-invasive treatment option. In nine subjects, percutaneous PNS improved participants' function, as evidenced by clinically and statistically significant reductions in pain, disability, and pain interference. Subjects also experienced reductions in opioid and non-opioid analgesic medication usage and reported improvements in quality of life with treatment. There were no serious or unanticipated adverse events. These results demonstrate the potential of percutaneous PNS as a non-surgical therapy to treat chronic back pain without opioids.

Clinical classification criteria for nonspecific low back pain: A Delphi-survey of clinical experts

BACKGROUND

Nonspecific low back pain (NSLBP) is a common problem. Attempts have been made to classify NSLBP patients into homogenous subgroups. Classification systems based on identifying the underlying mechanism(s) driving the disorder are clinically useful to guide specific interventions.

OBJECTIVE

To establish consensus among experts regarding clinical criteria suggestive of a dominance of 'articular', 'myofascial', 'neural', 'central', and 'sensorimotor control' dysfunction patterns (DPs) in NSLBP patients.

STUDY DESIGN

A 2-phase sequential design of a focus group and Delphi-study.

METHODS

A focus group with 10 academic experts was organized to elaborate on the different DPs discernible in LBP patients. Consecutively, a 3-round online Delphi-survey was designed to obtain consensual symptoms and physical examination findings for the 5 DPs resulting from the focus group.

RESULTS

Fifteen musculoskeletal physical therapists from Belgium and the Netherlands experienced in assessing and treating LBP patients completed the Delphi-survey. Respectively, 34 (response rate, 100.0%), 20 (58.8%) and 15 (44.12%) respondents replied to rounds 1, 2 and 3. Twenty-two 'articular', 20 'myofascial', 21 'neural', 18 'central' and 11 'sensorimotor control' criteria reached a predefined ≥80% consensus level. For example, after round 2, 85.0% of the Delphi-experts agreed to identify 'referred pain below the knee' as a subjective examination criterion suggestive for a predominant 'neural DP'.

CONCLUSION

These indicators suggestive of a clinical dominance of the proposed DPs could help clinicians to assess and diagnose NSLBP patients. Future reliability and validity testing is needed to determine how these criteria may help to improve physical therapy outcome for NSLBP patients.

New Therapy for Refractory Chronic Mechanical Low Back Pain-Restorative Neurostimulation to Activate the Lumbar Multifidus: One Year Results of a Prospective Multicenter Clinical Trial

Objectives

The purpose of the international multicenter prospective single arm clinical trial was to evaluate restorative neurostimulation eliciting episodic contraction of the lumbar multifidus for treatment of chronic mechanical low back pain (CMLBP) in patients who have failed conventional therapy and are not candidates for surgery or spinal cord stimulation (SCS).

Materials and Methods

Fifty‐three subjects were implanted with a neurostimulator (ReActiv8, Mainstay Medical Limited, Dublin, Ireland). Leads were positioned bilaterally with electrodes close to the medial branch of the L2 dorsal ramus nerve. The primary outcome measure was low back pain evaluated on a 10‐Point Numerical Rating Scale (NRS). Responders were defined as subjects with an improvement of at least the Minimal Clinically Important Difference (MCID) of ≥2‐point in low back pain NRS without a clinically meaningful increase in LBP medications at 90 days. Secondary outcome measures included Oswestry Disability Index (ODI) and Quality of Life (QoL; EQ‐5D).

Results

For 53 subjects with an average duration of CLBP of 14 years and average NRS of 7 and for whom no other therapies had provided satisfactory pain relief, the responder rate was 58%. The percentage of subjects at 90 days, six months, and one year with ≥MCID improvement in single day NRS was 63%, 61%, and 57%, respectively. Percentage of subjects with ≥MCID improvement in ODI was 52%, 57%, and 60% while those with ≥MCID improvement in EQ‐5D was 88%, 82%, and 81%. There were no unanticipated adverse events (AEs) or serious AEs related to the device, procedure, or therapy. The initial surgical approach led to a risk of lead fracture, which was mitigated by a modification to the surgical approach.

Conclusions

Electrical stimulation to elicit episodic lumbar multifidus contraction is a new treatment option for CMLBP. Results demonstrate clinically important, statistically significant, and lasting improvement in pain, disability, and QoL.

Muscle Control and Non-specific Chronic Low Back Pain

Objectives

Chronic low back pain (CLBP) is the most prevalent of the painful musculoskeletal conditions. CLBP is a heterogeneous condition with many causes and diagnoses, but there are few established therapies with strong evidence of effectiveness (or cost effectiveness). CLBP for which it is not possible to identify any specific cause is often referred to as non‐specific chronic LBP (NSCLBP). One type of NSCLBP is continuing and recurrent primarily nociceptive CLBP due to vertebral joint overload subsequent to functional instability of the lumbar spine. This condition may occur due to disruption of the motor control system to the key stabilizing muscles in the lumbar spine, particularly the lumbar multifidus muscle (MF).

Methods

This review presents the evidence for MF involvement in CLBP, mechanisms of action of disruption of control of the MF, and options for restoring control of the MF as a treatment for NSCLBP.

Results

Imaging assessment of motor control dysfunction of the MF in individual patients is fraught with difficulty. MRI or ultrasound imaging techniques, while reliable, have limited diagnostic or predictive utility. For some patients, restoration of motor control to the MF with specific exercises can be effective, but population results are not persuasive since most patients are unable to voluntarily contract the MF and may be inhibited from doing so due to arthrogenic muscle inhibition.

Conclusions

Targeting MF control with restorative neurostimulation promises a new treatment option.

Percutaneous Peripheral Nerve Stimulation for the Treatment of Chronic Low Back Pain: Two Clinical Case Reports of Sustained Pain Relief

As the leading cause of disability among U.S. adults, chronic low back pain (LBP) is one of the most prevalent and challenging musculoskeletal conditions. Neuromodulation provides an opportunity to reduce or eliminate the use of opioids to treat chronic LBP, but the cost and invasiveness of existing methods have limited its broad adoption, especially earlier in the treatment continuum. The present case report details the results of a novel method of short-term percutaneous peripheral nerve stimulation (PNS) in 2 subjects with chronic LBP. At the end of the 1-month therapy, stimulation was discontinued and the leads were withdrawn. PNS produced clinically significant improvements in pain (62% average reduction in Brief Pain Inventory Question #5, average pain), and functional outcomes (73% reduction in disability, Oswestry Disability Index; 83% reduction in pain interference, Brief Pain Inventory). Both subjects reduced nonopioid analgesic use by 83%, on average, and the one subject taking opioids ceased using all opioids. The only adverse event was minor skin irritation caused by a topical dressing. The clinically significant improvements were sustained at least 4 months after start of therapy (79% average reduction in pain; both reported minimal disability; 100% reduction in opioids; 74% reduction nonopioids). The results reveal the utility of this novel, short-term approach and its potential as a minimally invasive neuromodulation therapy for use earlier in the treatment continuum to produce sustained pain relief and reduce or eliminate the need for analgesic medications, including opioids, as well as more expensive and invasive surgical or therapeutic alternatives.

Recent advances in spinal cord stimulation for pain treatment

Traditional (40–50 Hz) spinal column stimulation is an efficacious and widely accepted treatment for chronic neuropathic pain conditions. However, there are major challenges including its ineffectiveness for axial back pain, the burden of paresthesia-related discomfort and difficulties producing indisputable research. Recently, there have been the major technological innovations of high-frequency and burst stimulation. Studies have shown these to provide improved analgesia even for axial pain without the problems associated with paresthesia. Dorsal root ganglion stimulation may be useful in certain subsets of patients with dermatomal distribution of pain. Other scientific data and technological improvements such as recent research on cost–effectiveness, MRI compatibility and very recent advances in spinal column stimulation are appraised.

Lumbar Muscle Cross-Sectional Areas Do Not Predict Clinical Outcomes in Adults With Spinal Stenosis: A Longitudinal Study

BACKGROUND

Minimal longitudinal data exist regarding the role of lumbar musculature in predicting back pain and function. In cross-sectional study designs, there is often atrophy of the segmental multifidus muscle in subjects with low back pain compared with matched controls. However, the cross-sectional design of these studies prevents drawing conclusions regarding whether lumbar muscle characteristics predict or modify future back pain or function.

OBJECTIVE

The primary objective of this study is to determine whether the cross-sectional area (CSA) of lumbar muscles predict functional status or back pain at 6- or 12-month follow-up in older adults with spinal degeneration. The secondary objective is to evaluate whether these muscle characteristics improve outcome prediction above and beyond the prognostic information conferred by demographic and psychosocial variables.

DESIGN

Secondary analysis of a randomized controlled trial.

PARTICIPANTS

A total of 209 adults aged 50 years and older with clinical and radiographic spinal stenosis from the Lumbar Epidural steroid injection for Spinal Stenosis (LESS) trial.

METHODS

Using baseline magnetic resonance images, we calculated CSAs of the lumbar multifidus, psoas, and quadratus lumborum muscles using a standardized protocol by manually tracing the borders of each of the muscles. The relationship between lumbar muscle CSAs and baseline measures was assessed with Pearson or Spearman correlation coefficients. The relationship between lumbar muscle characteristics and 6- and 12-month Roland Morris Disability Questionnaire (RDQ) and back pain Numeric Rating Scale (NRS) responses was further evaluated with multivariate linear regression. A hierarchical approach to the regression was performed: a basic model with factors of conceptual importance including age, gender, BMI, and baseline RDQ score formed the first step. The second and third steps evaluated whether psychosocial variables or muscle measures conferred additional prognostic information to the basic model.

MAIN OUTCOME MEASURES

Function as measured by the RDQ and back pain as measured by the NRS at 6- and 12-month follow-up.

RESULTS

Lumbar muscle CSA was not a significant predictor of 6- or 12-month RDQ or pain score in multivariate analyses.

CONCLUSIONS

Cross-sectional areas of lumbar muscles do not predict function or pain at medium- and long-term follow-up in adults with lumbar spinal stenosis.

LEVEL OF EVIDENCE

III.

The effect of Graston technique on the pain and range of motion in patients with chronic low back pain

[Purpose] Clinicians have reported the effects of various instrument assisted soft tissue mobilization (IASTM) in patients. The purpose of this study was to investigated the effects of the Graston technique and general exercise on pain and range of motion (ROM) in patients with CLBP. [Subjects and Methods] 30 patients with CLBP participated in the study (Graston technique: 15; Control: 15). Before and after the 4-week intervention program, pain was assessed using a visual analog scale (VAS). Lumbar ROM was measured using a smartphone. The main effects and interaction were analyzed by two-way repeated ANOVA. [Results] A significant time-by-group interaction was observed for the VAS and ROM. A post hoc paired t-test showed that pain decreased significantly post-intervention within the Graston group. The lumbar ROM significantly increased post-intervention in both groups. [Conclusion] The Graston technique and general exercise resulted in pain relief and increased ROM. However, the Graston group showed significantly increased VAS and ROM more than control group. These findings suggest that the Graston technique can be useful as a pain decrease and ROM increase for patients with CLBP.