Trends in lumbar radiofrequency ablation utilization from 2007 to 2016

Multifidus atrophy and/or dysfunction following lumbar radiofrequency ablation: A systematic review

BACKGROUND

Lumbar medial branch nerve radiofrequency ablation (LRFA) is an interventional procedure used to treat chronic lumbar facet joint pain. Because the medial branch nerves also innervate the multifidus muscle, it has been proposed that LRFA may pose a risk of multifidus atrophy and/or dysfunction. However, the quality and level of evidence to answer this clinical question have not been established. Therefore, this review aimed to systematically appraise the literature to discern whether the prevailing evidence substantiates the hypothesis in question.

METHODS

A systematic review compliant with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed to evaluate the quality and level of evidence of studies reporting functional and/or structural changes in the multifidus muscle following LRFA.

RESULTS

Only five cohort studies met inclusion criteria. Two studies assessed changes in multifidus function following LRFA with confirmed denervation at electromyography and significant reduction in multifidus shear modulus with ultrasound shear wave elastography. Of the four studies that evaluated changes in multifidus structure with magnetic resonance imaging following LRFA, two demonstrated a decrease in cross-sectional area or an increase in fat infiltration, one demonstrated no change, and one revealed an apparent increase. Given the destructive nature attributed to LRFA, some degree of multifidus atrophy and/or dysfunction may be plausible, albeit with a very low certainty that relies on a restricted body of literature of modest quality and with a presence of high bias.

CONCLUSION

There is a paucity of studies discussing the potential association between LRFA and multifidus atrophy and/or dysfunction. In light of the shortage of high-quality studies and the absence of standardized protocols to assess both changes in the structure and function of the multifidus subsequent to LRFA, there is a pressing need for more prospective studies with a high methodological rigor to comprehensively address and answer this enduring debate in clinical practice.

Cryoneurolysis versus radiofrequency ablation outcome on pain experience in chronic low back pain (COPE): a single-blinded randomised controlled trial

OBJECTIVE

A comparison of cryoneurolysis or radio frequency (RF) with placebo in patients with facetogenic chronic low back pain (LBP) for patient global impression of change (PGIC), pain intensity, function and quality of life, with 1-year follow-up.

DESIGN

Single-centre, single-blinded placebo-controlled randomised controlled trial.

SETTING

Single-centre study.

PARTICIPANTS

Inclusion from March 2020 to September 2022: consenting adults over 18 years of age, LBP>3 months, average Numeric Rating Scale LBP≥4 average last 14 days and a positive response to a diagnostic medial branch block (>50% pain reduction after 60 min).

INTERVENTIONS

120 patients were block randomised 1:1:1 to cryoneurolysis, RF or placebo of the medial branch nerves. Physical therapy was added after 4 weeks for all groups.

MAIN OUTCOME MEASURES

Primary outcome was PGIC 4 weeks after the intervention. Secondary outcomes included pain intensity (Numeric Rating Scale, NRS), quality of life (Short Form 36, EQ-5D-5L), disability (Oswestry Disability Index), depression (Major Depression Inventory) and catastrophising (Pain Catastrophising Scale). Outcomes were measured at 4 weeks, 3, 6 and 12 months.

RESULTS

There was no statistically significant difference in PGIC at 4 weeks between cryoneurolysis and placebo (risk ratio (RR) 2; 95% CI 0.75 to 5.33, p=0.17) and RF and placebo (RR 1.6; 95% CI 0.57 to 4.49, p=0.37), except PGIC for cryoneurolysis at 6-month follow-up (RR 5.1; 95% CI 1.20 to 22.03, p=0.03). No statistically significant differences were found in secondary follow-up endpoints.

CONCLUSIONS

Denervation of the medial branch nerve by either cryoneurolysis or RF compared with placebo did not demonstrate significant improvement in PGIC, pain intensity, function and quality of life in patients with facetogenic chronic LBP at short-term or long-term follow-up.

TRIAL REGISTRATION NUMBER

NCT04786145.

Efficacy and safety of radiofrequency ablation versus surgical sympathectomy in palmar hyperhidrosis

Radiofrequency ablation (RFA) comparative efficacy of treatments using video-assisted thoracoscopic sympathectomy (VATS) in the long term remains uncertain in patients with palmar hyperhidrosis (PHH). This study aimed to compare the efficacy and safety of RFA and VATS in patients with PHH. We recruited patients aged ≥ 14 years with diagnosed PHH from 14 centres in China. The treatment options of RFA or VATS were assigned to two cohort in patients with PHH. The primary outcome was the efficacy at 1-year. A total of 807 patients were enrolled. After propensity score matching, the rate of complete remission was lower in RFA group than VATS group (95% CI 0.21-0.57; p < 0.001). However, the rates of palmar dryness (95% CI 0.38-0.92; p = 0.020), postoperative pain (95% CI 0.13-0.33; p < 0.001), and surgery-related complications (95% CI 0.19-0.85; p = 0.020) were lower in RFA group than in VATS group, but skin temperature rise was more common in RFA group (95% CI 1.84-3.58; p < 0.001). RFA had a lower success rate than VATS for the complete remission of PHH. However, the symptom burden and cost are lower in patients undergoing RFA compared to those undergoing VATS.Trial Registration: ChiCTR2000039576, URL: http://www.chictr.org.cn/index.aspx .

Asymmetrical atrophy of the paraspinal muscles in patients undergoing unilateral lumbar medial branch radiofrequency neurotomy

ABSTRACT

Lumbar medial branch radiofrequency neurotomy (RFN), a common treatment for chronic low back pain due to facet joint osteoarthritis (FJOA), may amplify paraspinal muscle atrophy due to denervation. This study aimed to investigate the asymmetry of paraspinal muscle morphology change in patients undergoing unilateral lumbar medial branch RFN. Data from patients who underwent RFN between March 2016 and October 2021 were retrospectively analyzed. Lumbar foramina stenosis (LFS), FJOA, and fatty infiltration (FI) functional cross-sectional area (fCSA) of the paraspinal muscles were assessed on preinterventional and minimum 2-year postinterventional MRI. Wilcoxon signed-rank tests compared measurements between sides. A total of 51 levels of 24 patients were included in the analysis, with 102 sides compared. Baseline MRI measurements did not differ significantly between the RFN side and the contralateral side. The RFN side had a higher increase in multifidus FI (+4.2% [0.3-7.8] vs +2.0% [-2.2 to 6.2], P = 0.005) and a higher decrease in multifidus fCSA (-60.9 mm2 [-116.0 to 10.8] vs -19.6 mm2 [-80.3 to 44.8], P = 0.003) compared with the contralateral side. The change in erector spinae FI and fCSA did not differ between sides. The RFN side had a higher increase in multifidus muscle atrophy compared with the contralateral side. The absence of significant preinterventional degenerative asymmetry and the specificity of the effect to the multifidus muscle suggest a link to RFN. These findings highlight the importance of considering the long-term effects of lumbar medial branch RFN on paraspinal muscle health.

Impact of temperature on the magnitude and duration of relief after lumbar facets medial branch nerves radiofrequency ablation: a randomized double-blinded study

INTRODUCTION

There are numerous studies appraising the variables that may influence the clinical outcomes after lumbar thermal radiofrequency ablation (RFA). Expanding the lesion size may increase the likelihood of capturing the target nerves in the lesion, thereby increasing the technical success rate of RFA. However, our literature search has failed to identify a consensus on the optimal target temperature. A retrospective study demonstrated that there seems to be significant functional improvement associated with the temperature of 90°C compared with 80°C. The authors prospectively studied the subject in a double-blinded randomized fashion.

METHODS

Patients undergoing RFA for lumbar facetogenic pain were randomized in two cohorts (80°C and 90°C). Physicians and patients were blinded to the temperature used. The primary outcome was self-reported pain scores up to 12 months. Secondary outcomes included: self-reported functional improvement, duration of relief as measured by the time before repeat ablation of the same medial branches nerves, opioids' consumption, and patient satisfaction.

RESULTS

Both groups reported pain improvement in all follow-up time points. Overall, both groups achieved statistically significant pain reduction (p<0.05). The median time to repeat RFA in the 80°C group was 112 (49-252) days, while it was 217 (198-348) days in the 90°C group (p<0.04). The univariate analysis emphasized that the RFA temperature is a statistically significant factor for pain improvement of more than 50%, OR 2.7 (1.1 to 6.6) p value=0.031.

CONCLUSION

RFA has been demonstrated as an effective therapeutic modality for lumbar facetogenic back pain. Yet, the several factors involved in determining a favorable outcome of this procedure require further research and optimization. This prospective double-blinded randomized trial demonstrated that RFA at both temperatures (80°C, 90°C) provided significance at all the time periods examined. However, RFA at 90°C was superior to 80°C in regard to the duration of relief.

Percutaneous radiofrequency ablation and endoscopic neurotomy for lumbar facet joint syndrome: are they good enough?

OBJECTIVE

Lumbar facet joint (LFJ) syndrome is one of the common causes of low back pain (LBP). There are different views on percutaneous and endoscopic radiofrequency. The purpose of this systematic review and meta-analysis is to explore the therapeutic effect of radiofrequency ablation on LBP originating from LFJ and compare the therapeutic effect of percutaneous radiofrequency ablation and endoscopic neurotomy.

METHODS

We included randomized controlled trials which compared the efficiency of percutaneous radiofrequency ablation and conservative treatment (sham procedures, facet joint injection, physiotherapy, exercise, or oral medication) or compared the efficiency of percutaneous radiofrequency ablation and endoscopic neurotomy for LFJ syndrome. We searched in PubMed and Web of Science from inception to March 27, 2023. Meta-analysis was performed using RevMan 5.4 software.

RESULTS

A total of 11 randomized controlled trials were included. Among them, nine studies were used for evaluating efficiency of percutaneous radiofrequency ablation, and two studies were used for evaluating efficiency of endoscopic neurotomy. Pooled data from two studies reporting outcomes at 1 year did not show a benefit from facet joint denervation by comparing the percutaneous radiofrequency ablation and conservative treatment (standardized mean difference (SMD) = -0.87, 95% confidence interval (CI) [-2.10, 0.37], P = 0.17). There was no significant difference between percutaneous radiofrequency ablation and endoscopic neurotomy at 1-month follow-up (mean difference (MD) = -0.13, 95%CI [-0.18, -0.44], P = 0.41). At 12-month follow-up the pain relief in the endoscopic neurotomy was significantly better than that in the percutaneous radiofrequency ablation group (MD = 1.98, 95%CI [1.60, 2.36], P < 0 .0001).

CONCLUSION

The LBP was significantly relieved shortly after percutaneous radiofrequency ablation. Compared with percutaneous radiofrequency ablation, endoscopic neurotomy seems to have a longer effect. A longer follow-up period is needed to confirm its effectiveness.

Quantification of needle angles for lumbar medial branch denervation targeting the posterior half of the superior articular process: an osteological study

BACKGROUND

Lumbar medial branch radiofrequency ablation (RFA) is a common intervention to manage chronic axial low back pain originating from the facet joints. A more parasagittal approach targeting the posterior half of the lateral neck of superior articular process (SAP) was previously proposed. However, specific needle angles to achieve parallel placement at this target site have not been investigated.

OBJECTIVE

To quantify and compare the needle angles, on posterior and lateral views, to achieve parallel placement of electrodes along the medial branch at the posterior half of the lateral neck of SAP at each lumbar vertebral level (L1-L5) and sacrum.

DESIGN

Osteological Study.

METHODS

Twelve disarticulated lumbosacral spines (n = 72 individual bones) were used in this study. Needles were placed along the periosteum of the posterior half of the lateral neck of SAP, bilaterally and photographed. Mean needle angles for each vertebral level (L1-L5) and sacrum were quantified, and statistical differences were analyzed.

RESULTS

The posterior view provided the degrees of lateral displacement from the parasagittal plane (abduction angle), while the lateral view provided the degrees of declination (cranial-to-caudal angle) of the needle. Mean needle angles at each level varied, ranging from 5.63 ± 5.76° to 14.50 ± 14.24° (abduction angle, posterior view) and 40.17 ± 7.32° to 64.10 ± 9.73° (cranial-to-caudal angle, lateral view). In posterior view, a < 10-degree needle angle interval was most frequently identified (57.0% of needle placements). In lateral view, the 40-50-degree (L1-L2), 50-60-degree (L3-L5), and 60-70-degree (sacrum) needle angle intervals occurred most frequently (54.2%, 50.0%, and 41.7% of needle placements, respectively).

CONCLUSIONS

Targeting the posterior half of the lateral neck of SAP required <10-degree angulation from parasagittal plane in majority of cases. However, variability of needle angles suggests a standard "one-size-fits-all" approach may not be the optimal technique.

Low back pain-related healthcare utilization following intraosseous basivertebral nerve radiofrequency ablation: a pooled analysis from three prospective clinical trials

BACKGROUND

The effectiveness and safety of intraosseous basivertebral nerve ablation (BVNA) for treating vertebrogenic pain is established, but low back pain-related healthcare utilization (LBPr-HU) following BVNA continues to be defined.

METHODS

LBPr-HU data were pooled from 3 prospective studies. LBPr-HU categories of interest included non-invasive conservative care, opioid utilization, lumbosacral spinal injection (LSI), lumbosacral radiofrequency ablation (LRFA), and lumbosacral spinal surgery. Pre- and post-BVNA LBPr-HU were compared at both 1- and 5-years using McNemar's test for proportions and paired t-tests for means.

RESULTS

Two hundred forty-seven patients received BVNA and had 1-year follow-up; 205 had long-term follow-up (mean of 5.3 ± 1.33 years). Twenty-seven percent fewer participants initiated conservative care in the year post-BVNA compared to the year preceding BVNA (P < .001; 95% CI 19.8-34.5). Of 77/247 participants taking opioids at baseline, 40.3% and 61.7% fewer were taking them at one-year and 5.3 ± 1.33 years post-BVNA, respectively (P < .001). Of participants receiving LSIs in the year preceding BVNA, 81.2% fewer received LSI(s) in the year post-BVNA (P < .001; 95% CI 70.7-90.7); a 76.4% reduction in LSIs was maintained through a mean of 5.3 ± 1.33 years post-BVNA. LRFA rates were 1.6% at 1-year post-BVNA and 8.3% at 5.3 ± 1.33 years post-BVNA. Lumbar fusion surgery was 0.8% at 1-year post-BVNA and 6.5% at 5.3 ± 1.33 years post-BVNA.

CONCLUSIONS

In this aggregate analysis of patients with vertebrogenic pain, utilization of conservative care, opioids, LSIs, and LRFA were substantially reduced through 5 years post-BVNA compared to baseline. Lumbar fusion rates were less than half the published value at 5 years in similar populations.

A pragmatic randomized prospective trial of cooled radiofrequency ablation of the medial branch nerves versus facet joint injection of corticosteroid for the treatment of lumbar facet syndrome: 12 month outcomes

BACKGROUND

Lumbar medial branch radiofrequency ablation (LRFA) and intraarticular facet steroid injections (FJI) are commonly performed for recalcitrant facet joint-mediated pain. However, no study has compared clinical outcomes of the two treatments in patients selected using dual medial branch blocks (MBBs) with an 80% relief threshold.

OBJECTIVE

Compare the effectiveness of cooled LRFA (C-LRFA) to FIJ as assessed by pain and functional improvements.

DESIGN

Prospective randomized comparative trial.

METHODS

Patients with dual MBB-confirmed facet joint-mediated pain were randomized to receive C-LRFA or FIJ. Outcomes were assessed at 1, 3, 6, and 12 months. The primary outcome was ≥50% improvement in numerical pain rating scale (NPRS) score at 3 months. Secondary outcomes included ≥30% Oswestry Disability Index (ODI) improvement and Patient Global Impression of Chance (PGIC) ≥6 points, among others. Data were analyzed using contingency tables and mixed-effects logistic regression models.

RESULTS

Of 1128 patients screened, 32 met eligibility criteria, were randomized, and received their allocated study treatment. In total, 20 (62.5%) and 12 (37.5%) participants received C-LRFA and FIJ, respectively. In the C-LRFA group, 70% (95% CI 48-85), 55% (95% CI 34-74), and 45% (95% CI 26-66) of participants met the NPRS responder definition, compared to 25% (95%CI 9-53), 25% (95% CI 9-53), and 17% (95% CI 5-45) in the FJI group at 3, 6, and 12 months, respectively (P = .014 at 3 months). The PGIC responder proportion was higher in the C-LRFA compared to FJI group at 3 and 6 months (P < .05).

CONCLUSIONS

C-LRFA demonstrated superior success rates compared to FJI across pain and functional outcome domains.

TRIAL REGISTRATION DETAILS

ClinicalTrials.gov (NCT03614793); August 3, 2018.

Delphi-Based Expert Consensus Statements for the Management of Percutaneous Radiofrequency Neurotomy in the Treatment of Lumbar Facet Joint Syndrome

INTRODUCTION

A modified Delphi strategy was implemented for obtaining recommendations that could be useful in the management of percutaneous radiofrequency treatment of lumbar facet joint syndrome, as the literature on the argument was poor in quality.

METHODS

An Italian research team conducted a comprehensive literature search, defined the investigation topics (diagnosis, treatment, and outcome evaluation), and developed an explorative semi-structured questionnaire. They also selected the members of the panel. After an online meeting with the participants, the board developed a structured questionnaire of 15 closed statements (round 1). A five-point Likert scale was used and the cut-off for consensus was established at a minimum of 70% of the number of respondents (level of agreement ≥ 4, agree or strongly agree). The statements without consensus were rephrased (round 2).

RESULTS

Forty-one clinicians were included in the panel and responded in both rounds. After the first round, consensus (≥ 70%) was obtained in 9 out of 15 statements. In the second round, only one out of six statements reached the threshold. The lack of consensus was observed for statements concerning the use of imaging for a diagnosis [54%, median 4, interquartile range (IQR) 3-5], number of diagnostic blocks (37%, median 4, IQR 2-4), bilateral denervation (59%, median 4, IQR 2-4), technique and number of lesions (66%, median 4, IQR 3-5), and strategy after denervation failure (68%, median 4, IQR 3-4).

CONCLUSION

Results of the Delphi investigations suggest that there is a need to define standardized protocols to address this clinical problem. This step is essential for designing high-quality studies and filling current gaps in scientific evidence.

Estimating individualized treatment effects using a risk-modeling approach: an application to epidural steroid injections for lumbar spinal stenosis

ABSTRACT

Conventional "1-variable-at-a-time" analyses to identify treatment effect modifiers are often underpowered and prone to false-positive results. This study used a "risk-modeling" approach guided by the Predictive Approaches to Treatment effect Heterogeneity (PATH) Statement framework: (1) developing and validating a multivariable model to estimate predicted future back-related functional limitations as measured by the Roland-Morris Disability Questionnaire (RMDQ) and (2) stratifying patients from a randomized controlled trial (RCT) of lumbar epidural steroid injections (LESIs) for the treatment of lumbar spinal stenosis into subgroups with different individualized treatment effects on RMDQ scores at the 3-week follow-up. Model development and validation were conducted in a cohort (n = 3259) randomly split into training and testing sets in a 4:1 ratio. The model was developed in the testing set using linear regression with least absolute shrinkage and selection regularization and 5-fold cross-validation. The model was then applied in the testing set and subsequently in patients receiving the control treatment in the RCT of LESI. R2 values in the training set, testing set, and RCT were 0.38, 0.32, and 0.34, respectively. There was statistically significant modification ( P = 0.03) of the LESI treatment effect according to predicted risk quartile, with clinically relevant LESI treatment effect point estimates in the 2 quartiles with greatest predicted risk (-3.7 and -3.3 RMDQ points) and no effect in the lowest 2 quartiles. A multivariable risk-modeling approach identified subgroups of patients with lumbar spinal stenosis with a clinically relevant treatment effect of LESI on back-related functional limitations.

Impact of the COVID-19 Pandemic on Utilization Patterns of Facet Joint Interventions in Managing Spinal Pain in a Medicare Population

INTRODUCTION

The COVID-19 pandemic resulted in major disruptions in all aspects of human life including a decline of medical services utilized during 2020. An analysis of the impact of COVID-19 pandemic showed an 18.7% reduction in utilization patterns of interventional techniques in managing chronic pain in the Medicare population from 2019 to 2020. However, specific changes in utilization patterns of facet joint interventions have not been studied. Thus, we sought to assess the utilization patterns including an update of facet joint interventions from 2018 to 2020, with analysis of the impact of COVID-19 pandemic in managing chronic spinal pain utilizing facet joint interventions in the fee-for-service Medicare population of the United States.

METHODS

The present investigation was designed to assess utilization patterns and variables of facet joint interventions, in managing chronic spinal pain from 2010 to 2020 in the fee-for-service (FFS) Medicare population in the United States (US), and how the COVID-19 pandemic impacted these utilization patterns. Data for the analysis were obtained from the master database from the Centers for Medicare & Medicaid Services (CMS) physician/supplier procedure summary from 2000 to 2020.

RESULTS

Results of this analysis showed significant impact of COVID-19 with overall decrease of 18.5% of all facet joint interventions per 100,000 Medicare population compared to 20.2 and 20.5% decrease for lumbar and cervical facet joint injections, 15 and 13.1% decrease per 100,000 Medicare population of lumbosacral and cervicothoracic facet joint neurolysis procedures. The results are significant in that comparative analysis from 2000 to 2010 and 2010 to 2019 showing an annual increase of 14.4 vs. 2.2%, illustrating a decelerating pattern. There were also significant growth patterns noted with decreases in facet joint injections and nerve blocks compared to facet joint neurolytic procedures.

CONCLUSIONS

This analysis shows a significant effect of COVID-19 producing an overall decrease in utilization of facet joint interventions relative to pre-COVID data. Further, the analysis demonstrates continued deceleration of utilization patterns of facet joint interventions compared to the periods of 2000-2010 and 2010-2019.

SpineRegNet: Spine Registration Network for volumetric MR and CT image by the joint estimation of an affine-elastic deformation field

Spine registration for volumetric magnetic resonance (MR) and computed tomography (CT) images plays a significant role in surgical planning and surgical navigation system for the radiofrequency ablation of spine intervertebral discs. The affine transformation of each vertebra and elastic deformation of the intervertebral disc exist at the same time. This situation is a major challenge in spine registration. Existing spinal image registration methods failed to solve the optimal affine-elastic deformation field (AEDF) simultaneously, only consider the overall rigid or elastic alignment with the help of a manual spine mask, and encounter difficulty in meeting the accuracy requirements of clinical registration application. In this study, we propose a novel affine-elastic registration framework named SpineRegNet. The SpineRegNet consists of a Multiple Affine Matrices Estimation (MAME) Module for multiple vertebrae alignment, an Affine-Elastic Fusion (AEF) Module for joint estimation of the overall AEDF, and a Local Rigidity Constraint (LRC) Module for preserving the rigidity of each vertebra. Experiments on T2-weighted volumetric MR and CT images show that the proposed approach achieves impressive performance with mean Dice similarity coefficients of 91.36%, 81.60%, and 83.08% for the mask of the vertebrae on Datasets A-C, respectively. The proposed technique does not require a mask or manual participation during the tests and provides a useful tool for clinical spinal disease surgical planning and surgical navigation systems.

Anatomical study of the medial branches of the lumbar dorsal rami: implications for image-guided intervention

INTRODUCTION

Fluoroscopic-guided radiofrequency ablation of the lumbar medial branches is commonly performed to manage chronic low back pain originating from the facet joints. A detailed understanding of the course of medial branches in relation to bony and soft tissue landmarks is paramount to optimizing lumbar denervation procedures, particularly parallel placement of the radiofrequency electrode. The objectives of this study were to investigate the relationship of medial branches to anatomical landmarks and discuss the implications for lumbar denervation.

METHODS

Ten cadaveric specimens were meticulously dissected. The origin, course, and relationship of lumbar medial branches to bony and soft tissue landmarks were documented.

RESULTS

The medial branches followed the lateral neck of superior articular process deep to the intertransversarii mediales muscle at each lumbar vertebral level. In all specimens, the medial branches coursed laterally on the anterior half of the neck and transitioned from parasagittal-to-medial on the posterior half to reach the mamillo-accessory notch. The mamillo-accessory ligament was found to not occlude the nerve on the posterior quarter of the lateral neck but rather at the mamillo-accessory notch located at the posterior margin of the superior articular process.

DISCUSSION

A detailed understanding of the relationship of medial branches to anatomical landmarks is essential to optimizing needle placement for lumbar denervation procedures. The current study suggests that a parasagittal placement, with increased cranial-to-caudal angulation of the electrode, may improve parallel tip alignment with the targeted medial branch and represent a potential alternative to the traditional technique.

An International Survey on the Practice of Lumbar Radiofrequency Ablation for Management of Zygapophyseal (Facet)-Mediated Low Back Pain

Objective

The objective of this study was to survey current clinical practice related to lumbar radiofrequency (RFA) for the treatment of zygapophyseal (facet)-mediated low back pain.

Methods

Survey questions regarding the clinical practice of lumbar RFA were created and piloted by the American Society of Pain and Neuroscience (ASPN) leadership. After revision for clarity, health-care professionals worldwide who hold membership status within the ASPN Society and who offer lumbar RFA in their clinical practice were recruited to participate in this online survey. All responses were tabulated and summarized descriptively.

Results

A total of 329 participants responded in the survey. Most participants specialized in anesthesiology (68.4%) and physical medicine and rehabilitation (21.8%) and had been practicing pain management for more than five years (70.5%). Of physician respondents, 27.5% did not complete an Accreditation Council for Graduate Medical Education (ACGME)-accredited pain medicine fellowship and 16.5% were not board-certified in pain medicine. The majority of providers (69.7%) reported that they perform two diagnostic medial branch blocks prior to proceeding with lumbar RFA. Bupivacaine 0.5% was the most common medication utilized for both the first (37.4%) and second (37.1%) diagnostic blocks. There were 32.6% of total respondents who reported not utilizing contrast dye when performing diagnostic blocks. The vast majority of providers (91.4%) reported using conventional RFA for lumbar medial branch neurotomy.

Conclusion

This survey study provides a summary of the application of lumbar RFA for the treatment of axial low back pain in the real-world setting. We highlight a significant portion of providers who perform lumbar RFA yet do not have pain fellowship training at an ACGME-accredited institution or do not maintain current pain medicine board certification. We also report deviations from standard practice, specifically the type of local anesthetic used for comparative diagnostic blocks and the omission of contrast injection during diagnostic blocks.

Latest Evidence-Based Application for Radiofrequency Neurotomy (LEARN): Best Practice Guidelines from the American Society of Pain and Neuroscience (ASPN)

Radiofrequency neurotomy (RFN), also known as radiofrequency ablation (RFA), is a common interventional procedure used to treat pain from an innervated structure. RFN has historically been used to treat chronic facet-joint mediated pain. The use of RFN has more recently expanded beyond facet-joint mediated pain to peripherally innervated targets. In addition, there has also been the emergence of different radiofrequency modalities, including pulsed and cooled RFN. The use of RFN has been particularly important where conservative and/or surgical measures have failed to provide pain relief. With the emergence of this therapeutic option and its novel applications, the American Society of Pain and Neuroscience (ASPN) identified the need for formal evidence-based guidance. The authors formed a multidisciplinary work group tasked to examine the latest evidence-based medicine for the various applications of RFN, including cervical, thoracic, lumbar spine; posterior sacroiliac joint pain; hip and knee joints; and occipital neuralgia. Best practice guidelines, evidence and consensus grading were provided for each anatomical target.

Providing Epidemiological Data in Lumbar Spine Imaging Reports Did Not Affect Subsequent Utilization of Spine Procedures: Secondary Outcomes from a Stepped-Wedge Randomized Controlled Trial

OBJECTIVE

To evaluate the effect of inserting epidemiological information into lumbar spine imaging reports on subsequent nonsurgical and surgical procedures involving the thoracolumbosacral spine and sacroiliac joints.

DESIGN

Analysis of secondary outcomes from the Lumbar Imaging with Reporting of Epidemiology (LIRE) pragmatic stepped-wedge randomized trial.

SETTING

Primary care clinics within four integrated health care systems in the United States.

SUBJECTS

238,886 patients ≥18 years of age who received lumbar diagnostic imaging between 2013 and 2016.

METHODS

Clinics were randomized to receive text containing age- and modality-specific epidemiological benchmarks indicating the prevalence of common spine imaging findings in people without low back pain, inserted into lumbar spine imaging reports (the "LIRE intervention"). The study outcomes were receiving 1) any nonsurgical lumbosacral or sacroiliac spine procedure (lumbosacral epidural steroid injection, facet joint injection, or facet joint radiofrequency ablation; or sacroiliac joint injection) or 2) any surgical procedure involving the lumbar, sacral, or thoracic spine (decompression surgery or spinal fusion or other spine surgery).

RESULTS

The LIRE intervention was not significantly associated with subsequent utilization of nonsurgical lumbosacral or sacroiliac spine procedures (odds ratio [OR] = 1.01, 95% confidence interval [CI] 0.93-1.09; P = 0.79) or any surgical procedure (OR = 0.99, 95 CI 0.91-1.07; P = 0.74) involving the lumbar, sacral, or thoracic spine. The intervention was also not significantly associated with any individual spine procedure.

CONCLUSIONS

Inserting epidemiological text into spine imaging reports had no effect on nonsurgical or surgical procedure utilization among patients receiving lumbar diagnostic imaging.

The Effectiveness of Radiofrequency Ablation of Medial Branch Nerves for Chronic Lumbar Facet Joint Syndrome in Patients Selected by Guideline-Concordant Dual Comparative Medial Branch Blocks

OBJECTIVES

Although the effectiveness of lumbar medial branch radiofrequency ablation (RFA) for the treatment of zygapophyseal joint (z-joint)-mediated low back pain has been characterized, few studies have described outcomes in patients selected using a guideline-concordant paradigm of ≥80% pain relief with dual comparative medial branch blocks (MBBs). We investigated long-term treatment outcomes of patients selected according to this paradigm.

DESIGN

Cross-sectional cohort study.

METHODS

The medical records of 111 consecutive patients were reviewed; 85 met inclusion criteria. A standardized telephone survey was used to capture current numerical rating scale (NRS) and Patient Global Impression of Change (PGIC) scores. The primary outcome was the proportion of patients reporting ≥50% reduction of index pain. Binary logistic regression analysis was performed to explore associations between the primary outcome and covariates, including age, duration of pain, presence of scoliosis, degenerative spondylolisthesis, and >75% disc height loss.

RESULTS

At six to 12, 12-24, and >24 months, 63.2% (95% confidence interval [CI] = 41-85%), 65.6% (95% CI = 49-82%), and 44.1% (95% CI = 27-61%) of patients reported a ≥50% pain reduction (P = 0.170), respectively. At a minimum of six months, 70.6% of patients reported a pain reduction of two or more points (minimally clinically important change), and 54.1% reported a PGIC score consistent with "much improved" or better. Older age and a smaller Cobb angle were associated with a ≥50% pain reduction (P < 0.05).

CONCLUSION

Lumbar medial branch RFA is an effective, durable treatment for a significant proportion of patients with recalcitrant lumbar z-joint pain when candidacy is determined by the guideline-concordant paradigm of ≥80% pain relief with dual comparative MBBs.

SpineParseNet: Spine Parsing for Volumetric MR Image by a Two-Stage Segmentation Framework With Semantic Image Representation

Spine parsing (i.e., multi-class segmentation of vertebrae and intervertebral discs (IVDs)) for volumetric magnetic resonance (MR) image plays a significant role in various spinal disease diagnoses and treatments of spine disorders, yet is still a challenge due to the inter-class similarity and intra-class variation of spine images. Existing fully convolutional network based methods failed to explicitly exploit the dependencies between different spinal structures. In this article, we propose a novel two-stage framework named SpineParseNet to achieve automated spine parsing for volumetric MR images. The SpineParseNet consists of a 3D graph convolutional segmentation network (GCSN) for 3D coarse segmentation and a 2D residual U-Net (ResUNet) for 2D segmentation refinement. In 3D GCSN, region pooling is employed to project the image representation to graph representation, in which each node representation denotes a specific spinal structure. The adjacency matrix of the graph is designed according to the connection of spinal structures. The graph representation is evolved by graph convolutions. Subsequently, the proposed region unpooling module re-projects the evolved graph representation to a semantic image representation, which facilitates the 3D GCSN to generate reliable coarse segmentation. Finally, the 2D ResUNet refines the segmentation. Experiments on T2-weighted volumetric MR images of 215 subjects show that SpineParseNet achieves impressive performance with mean Dice similarity coefficients of 87.32 ± 4.75%, 87.78 ± 4.64%, and 87.49 ± 3.81% for the segmentations of 10 vertebrae, 9 IVDs, and all 19 spinal structures respectively. The proposed method has great potential in clinical spinal disease diagnoses and treatments.

Therapeutic Facet Joint Interventions in the Lumbar Spine: An Economic Value Perspective

OBJECTIVE

In this narrative review, the current literature on therapeutic interventions for low back pain of facet joint etiology is assessed from an economic value perspective.

SUMMARY OF BACKGROUND DATA

The efficacy and economics of facet joint interventions in the treatment of lumbar back pain is a controversial topic. Trends show that facet joint interventions are becoming increasingly used, perhaps as physicians become more averse to treating chronic low back pain with opioids. With the emphasis on value-based spine care and changing reimbursement models, the perspective of rigorously evaluating the outcomes these interventions provide and the costs they incur is particularly relevant.

DISCUSSION

Although the evidence is noted to be limited, most systematic reviews fail to demonstrate the therapeutic utility of intra-articular facet joint injections in low back pain because of high study heterogeneity. A few good quality studies and systematic reviews describe moderate evidence for the utilization of therapeutic medial branch blocks and radiofrequency neurotomies in alleviating facet joint pain.

CONCLUSION

Consequently, there is a need for high-quality cost-effectiveness studies for facet joint interventions so that evidence-based and economically viable solutions can be used to optimize patient care at a societally affordable price.

Consensus practice guidelines on interventions for lumbar facet joint pain from a multispecialty, international working group

BACKGROUND

The past two decades have witnessed a surge in the use of lumbar facet blocks and radiofrequency ablation (RFA) to treat low back pain (LBP), yet nearly all aspects of the procedures remain controversial.

METHODS

After approval by the Board of Directors of the American Society of Regional Anesthesia and Pain Medicine, letters were sent to a dozen pain societies, as well as representatives from the US Departments of Veterans Affairs and Defense. A steering committee was convened to select preliminary questions, which were revised by the full committee. Questions were assigned to 4-5 person modules, who worked with the Subcommittee Lead and Committee Chair on preliminary versions, which were sent to the full committee. We used a modified Delphi method, whereby the questions were sent to the committee en bloc and comments were returned in a non-blinded fashion to the Chair, who incorporated the comments and sent out revised versions until consensus was reached.

RESULTS

17 questions were selected for guideline development, with 100% consensus achieved by committee members on all topics. All societies except for one approved every recommendation, with one society dissenting on two questions (number of blocks and cut-off for a positive block before RFA), but approving the document. Specific questions that were addressed included the value of history and physical examination in selecting patients for blocks, the value of imaging in patient selection, whether conservative treatment should be used before injections, whether imaging is necessary for block performance, the diagnostic and prognostic value of medial branch blocks (MBB) and intra-articular (IA) injections, the effects of sedation and injectate volume on validity, whether facet blocks have therapeutic value, what the ideal cut-off value is for a prognostic block, how many blocks should be performed before RFA, how electrodes should be oriented, the evidence for larger lesions, whether stimulation should be used before RFA, ways to mitigate complications, if different standards should be applied to clinical practice and clinical trials and the evidence for repeating RFA (see table 12 for summary).

CONCLUSIONS

Lumbar medial branch RFA may provide benefit to well-selected individuals, with MBB being more predictive than IA injections. More stringent selection criteria are likely to improve denervation outcomes, but at the expense of more false-negatives. Clinical trials should be tailored based on objectives, and selection criteria for some may be more stringent than what is ideal in clinical practice.

Repeat procedures and prescription opioid use after lumbar medial branch nerve radiofrequency ablation in commercially insured patients

PURPOSE

Although the effectiveness of medial branch nerve radiofrequency ablation (RFA) for lumbosacral facet pain has been described, little is known regarding patterns of repeat RFA utilization and prescription opioid use afterward.

DESIGN

Retrospective cohort analysis.

PATIENT SAMPLE

Patients undergoing lumbosacral RFA in MarketScan from 2007 to 2016.

METHODS

The time until and number of staged RFAs (<180 days after initial RFA) and repeat RFAs (≥180 days after initial RFA), as well as opioid use at 90 and 180 days after RFA were assessed. Survival analyses were employed to estimate subsequent RFA rates, whereas subsequent RFA frequencies were estimated with inverse probability weighting. Repeated measures testing was performed comparing opioid use pre- and post-RFA.

RESULTS

Initial RFAs were identified in 44,936 patients. Staged RFAs were performed in 33.1% of patients. Repeat RFAs through 1, 3, and 7 years were performed for 14.6%, 33.5%, and 45.7% of patients, respectively. Within 3 years, 12.2% of patients underwent one repeat RFA, whereas 13.2% of patients underwent two or more. Post-RFA opioid use was examined in 128,310 patients, 32.2% of whom used opioids pre-RFA. By 180 days post-RFA, 8.1% of patients discontinued opioids and 6.7% started opioids (p<.001). Exclusively examining pre-RFA opioid users, 24.9% stopped filling opioid prescriptions 180 days after RFA.

CONCLUSIONS

This study delineates utilization rates of repeat RFA in the commerciall y insured population, with one-third undergoing repeat RFA within 3 years. Additionally, the present data indicate that lumbosacral RFA is associated with reduced filling of opioid prescriptions through 180 days.