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

Lumbar facet joint denervation targeting the medial branch in the sub-mammillary fossa: An anatomical optimization study

Introduction

Recent anatomical studies have identified the sub-mammillary fossa as a potential target site to extend the length and more reliably capture the medial branch during lumbar facet joint denervation. Although a clinical case series was published describing positive outcomes targeting the sub-mammillary fossa, the ideal location for radiofrequency cannula placement has not been assessed. Further anatomical investigation of this novel technique is warranted to refine fluoroscopic landmarks for optimal placement.

Methods

Twelve cannulae were placed under fluoroscopic guidance targeting the L3, L4, & L5 medial branches in 2 embalmed cadaveric specimens. Dissection, digitization, and high-fidelity 3D modelling methodology was used to identify fluoroscopic landmarks. Lesion simulation was performed on 3D models to analyze nerve capture.

Results

In 5 of 12 placements (41.7 %), the medial branch capture rate was classified as "complete," as the simulated lesion overlapped with the medial branch trunk or all of its distal branches. In 4 of 12 placements (33.3 %), the nerve capture rate was "partial" with at least one distal branch found beyond the boundary of the simulated lesion. In the remaining 3 placements (25.0 %), the capture rate was classified as "none," as the medial branch trunk and all distal branches transited beyond the simulated lesion boundary. Refined fluoroscopic landmarks proposed were the lateral boundary of mammillary process (AP view); the mamillo-accessory notch/inferior boundary of facet joint line (oblique view); and the inferior aspect of the mammillary process (lateral view).

Conclusions

This anatomy optimization study used dissection, imaging correlation, and high-fidelity modelling to assess cannula placement for capture of the medial branch at the sub-mammillary fossa for lumbar facet joint denervation. Based on the present analysis, refined fluoroscopic landmarks were proposed for further investigation.

Assessment of real-world, prospective outcomes in patients treated with lumbar radiofrequency ablation for chronic pain (RAPID)

Background

Lumbar facet joint syndrome (LFJS) is one of most common forms of chronic low back pain. Despite several decades of real-world use and a plethora of published studies, debate still exists regarding the effectiveness of Radiofrequency Ablation (RFA) as a therapy in LFJS-diagnosed patients.

Objective

Here, we sought to evaluate real-world clinical outcomes in RFA-treated patients with chronic lumbar facetogenic pain participating in one of the largest studies of its kind published to date.

Methods

The RAPID study (Clinicaltrials.gov identifier: NCT04673032) is an international, multicenter, prospective study of patients using a commercially-available radiofrequency ablation system for the treatment of chronic pain, provided per standard of care. Patients were assessed at pre-specified study follow-up visits (1-, 3-. 6-, 12-, and 24-months post-index procedure). Key clinical endpoint measures collected and evaluated include NRS (pain score), Oswestry Disability Index (functional disability, ODI), EQ-5D-5L (quality-of-life), and Patient Global Impression of Change (PGIC).

Results

To date, 193 patients have been enrolled in this lumbar facetogenic pain patient cohort. Evaluation of pain relief amongst patients assessed out to 24-months demonstrated a mean NRS score of 3.4 (baseline NRS: 6.6, p < 0.0001). Consistent functional improvement out to 24-months was observed per an 8.6-point mean ODI score reduction (baseline ODI: 38.0, p < 0.0001). Following RFA treatment at 1-month and out to 24-months, 77.0% and 79.0% of patients were observed to be treatment responders (i.e., ≥50% pain relief), respectively. Enhanced levels in measures of quality-of-life (EQ-5D-5L) and self-reported health-related change (PGIC) were also consistently noted.

Conclusions

Clinically meaningful and durable improvements in pain relief, functional disability, quality-of-life and treatment satisfaction were observed across all RAPID study follow-up visits. The results of the RAPID study provide for the potential clinical outcomes amongst selected patients with lumbar facetogenic pain within the real-world clinical setting.

Radiologist's Guide to Lumbar Spine Pain Interventions: Indications, Techniques, and Complications

Knowledge of the pathophysiology of lumbar pain, appropriate patient selection, fluoroscopic anatomy, needle placement, and potential complications is crucial for successful lumbar spine pain interventions.

Targeting the lateral neck of superior articular process and sub-mammillary fossa for lumbar medial branch radiofrequency ablation: A case series

Introduction

Lumbar medial branch (MB) radiofrequency ablation (RFA) is a common image-guided procedure to treat facetogenic low back pain. Recent anatomical literature has proposed a two-lesion RFA approach targeting the posterior portion of the lateral neck of superior articular process (SAP) and the superior aspect of the sub-mammillary fossa. The objectives of this report were to: 1) describe the novel lumbar MB RFA technique, 2) discuss the relevant anatomy, and 3) report pain relief outcomes in four patients who gave informed consent to be treated with the novel two-landmark lumbar MB RFA technique.

Methods

Four patients were treated with the novel two-landmark lumbar MB RFA technique targeting the posterior half of the lateral neck of SAP and superior aspect of the sub-mammillary fossa. The quality and duration of pain relief following the treatment are described in this report.

Results

All 4 patients, who received the novel technique, self-reported quality of pain relief of ≥80 %. One patient, who self-reported 100 % pain relief, elected not to have repeat RFA treatment at their 15-month follow-up appointment. All 4 patients reported pain relief duration ≥12 months and stated the quality of pain relief following procedure was "excellent" or the "best result" they experienced.

Conclusions

This case series reports early evidence of the effectiveness of the two-landmark lumbar MB RFA technique. The novel approach shows promise in a limited number of patient cases and warrants further investigation.

CellKine clinical trial: first report from a phase 1 trial of allogeneic bone marrow-derived mesenchymal stem cells in subjects with painful lumbar facet joint arthropathy

Background

Lumbar facet joint arthropathy (LFJA) is a major cause of low back pain (LBP), with current treatments offering limited long-term benefits. Bone marrow-derived mesenchymal stem cells (BM-MSCs) show promise due to their immunomodulatory and trophic effects, potentially addressing underlying degenerative processes in LFJA.

Objectives

This initial report describes the outcomes of the first treated patient in an ongoing mutidisciplinary phase 1 clinical trial evaluating the safety and feasibility of intra-articular allogeneic BM-MSCs for painful LFJA.

Methods

Following enrollment in our IRB-approved protocol, symptomatic LFJA was confirmed through double blocks on L4 and L5 medial branches. Two 1-mL syringes, each containing 10 million BM-MSCs, were prepared in the cGMP facility and administered bilaterally to the patient's L4-L5 lumbar facet joints. The patient underwent standardized follow-ups, including clinical examinations and functional and imaging assessments for 2 years, utilizing patient-reported outcomes measurement information system-computer adaptive tests (PROMIS CATs), visual analogue scale, Oswestry disability index, work functional status and opioid pain medication use, and MR imaging Fenton-Czervionke score.

Results

The patient tolerated the procedure well, with no drug-related adverse events during the study period. Pain, spine function, and work functional status improved at multiple follow-ups. This patient also reported improvements in mental and social health, along with a notable improvement in the grade of facet synovitis observed at the one-year follow-up MRI evaluation.

Conclusions

This case report suggests the safety and feasibility of administering intra-articular allogeneic BM-MSCs, offering therapeutic benefits for pain management and functional activities.

Image-guided peripheral nerve interventions- applications and techniques

Interventional radiology continues to be at the forefront of acute and chronic pain management. Our unique imaging expertise and ability to target difficult to reach structures allows for the continuous development of new ways to treat a variety of pain generators. In addition, the advent of thermal ablation techniques and technologies has provided a unique opportunity to offer patients more durable and predictable options to treat their pain. This is particularly important during the opioid epidemic, as multiple local and international governmental bodies push for physicians to create ways to manage pain while reducing the need for long-term opioid dependence. This article aims to review various image-guided techniques and tools for the treatment of pain related to peripheral pain generators, with a focus on the extremities, lumbosacral and pelvic region, and the chest wall. For each target and pathology, we will discuss general etiology, anatomy, procedural approach, and briefly evaluate the supporting literature in each clinical situation.

Parasagittal needle placement approach for lumbar medial branch denervation: a brief technical report

Radiofrequency denervation of lumbar medial branches is a viable treatment option to manage chronic facetogenic low back pain. Traditionally, lumbar medial branch denervation involves placement of the electrode's active tip at a 20-degree angulation away from the parasagittal plane. However, more recent anatomical studies have provided evidence supporting the feasibility of an alternative parasagittal approach targeting the posterior half of the lateral neck of the superior articular process to capture the lumbar medial branches. Currently, there is a lack of clinical data on the effectiveness of the alternative parasagittal needle placement technique. Therefore, in this brief technical report, the parasagittal needle placement technique and the pain relief outcomes in four consecutive patients following treatment with the parasagittal approach are described.

Comparison of the Efficacy of Different Radiofrequency Techniques for the Treatment of Lumbar Facet Joint Pain: Combined with Anatomy

PURPOSE OF REVIEW

Lumbar facet pain is generally considered to be one of the major causes of chronic low back pain. Each lumbar facet joint is innervated by the medial branch of the posterior spinal nerve from its own level and above. Radiofrequency (RF) of the medial branch of the posterior branch of the spinal nerve is an effective method for the treatment of lumbar facet pain. RF technology is diverse, including traditional radiofrequency (TRF), pulsed radiofrequency (PRF), cooled radiofrequency (CRF), low-temperature plasma radiofrequency ablation (CA), and other treatment methods. The purpose of this paper is to compare the efficacy of different radiofrequency techniques and to analyze the reasons for this in the context of anatomy.

RECENT FINDINGS

There have been studies confirming the differences in efficacy of different RF techniques. However, most of the studies only compared two RF techniques, not four techniques, TRF, CRF, PRF, and CA, and did not analyze the reasons for the differences in efficacy. This article reviews the differences in the efficacy of the above four RF techniques, clarifies that the differences are mainly due to the inability to precisely localize the medial branch of the posterior branch of the spinal nerve, analyzes the reasons for the inability to precisely localize the posterior branch of the spinal nerve in conjunction with anatomy, and proposes that the development of RF technology for lumbar facet pain requires more in-depth anatomical, imaging, and clinical studies.

The effect of lumbar medial branch radiofrequency neurotomy on cobb angle progression in individuals with adult scoliosis compared to natural history: A cross-sectional study

Background

Lumbar radiofrequency neurotomy (LRFN) effectively alleviates zygapophyseal joint-mediated pain by coagulating medial branch nerves to disrupt nociceptive signaling pathways. The concomitant denervation of multifidus fibers has led to concern that LRFN may increase segmental instability and accelerate degenerative changes in patients with certain pre-existing spinal pathologies. There is a paucity of literature evaluating whether LRFN increases the progression of spinal curvature in patients with adult scoliosis.

Objective

Compare the lumbosacral Cobb angle progression rate in patients with adult scoliosis who underwent LRFN to the annual progression rate of 0.83 ± 1.1° expected by natural history.

Design

Cross-sectional study.

Methods

Consecutive patients diagnosed with adult scoliosis who underwent LRFN to treat zygapophyseal joint-related low back pain were identified. Patient demographics, LRFN procedure details, and radiographs confirming scoliosis were collected from electronic medical records. Pre- and post-LRFN radiographs were used to calculate the average annual rate of Cobb angle progression. Data were analyzed using a Wilcoxon signed-rank test and a linear regression model.

Results

Sixty patients (mean age 69.2 ± 11.6 years; 70.0 % female) met the criteria and were included in the analyses. The mean time to radiographic follow-up was 35.0 ± 22.7 months post-LRFN. The average Cobb angle progression was 0.54 ± 3.03° per year and did not differ significantly from the known natural progression rate of 0.83 ± 1.1° per year. None of the included covariates (body mass index, LRFN laterality, and number of levels denervated) were significantly associated with the average annual Cobb angle progression rate.

Conclusions

Our results suggest that LRFN has no appreciable effect on the rate of Cobb angle progression in patients with adult scoliosis.

Anatomical Observation and Clinical Significance of the Medial Branch of the Lumbar Dorsal Rami

STUDY DESIGN

Anatomical study.

OBJECTIVE

This study aimed to elaborate on the anatomical characteristics of the medial branch of the lumbar dorsal rami and to discuss its possible clinical significance.

SUMMARY OF BACKGROUND DATA

Radiofrequency ablation targeting the medial branch of the lumbar dorsal rami has been increasingly used in the clinical management of facetogenic low back pain (FLBP). Nonetheless, attention is also being given to complications such as atrophy of the lumbar soft tissues and muscles. Therefore, a more detailed understanding of the innervation pattern on the facet joint may improve the precision of nerve ablation therapy for FLBP.

METHODS

An anatomical study of eight human specimens was carried out. The anatomic characteristics of the medial branch were observed and recorded.

RESULTS

The medial branch originates from the lumbar dorsal rami, running close to the root of the posterolateral side of the superior articular process of the inferior cone. When passed through the mamillo-accessory ligament, it turns direction to the medial and caudal side, running in the multifidus muscle. In our study, each medial branch sent out two to five branches along the way. All the medial branches in L1-L4 gave off one to two small branches when crossing the facet joint and innervated the joint of the lower segment. Nineteen medial branches (23.75%) gave off recurrent branches to innervate the joint at the upper segment.

CONCLUSION

The anatomical features of the medial branch remain similar in each lumbar segment. There are two types of joint branches, including the articular fibers that emanate from the medial branch as it runs along the medial border of the facet joint and the recurrent branch from the medial branch that innervates the upper facet joint. Moreover, an anastomotic branch was found in the medial branches between different segments.

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.

3. Pain originating from the lumbar facet joints

INTRODUCTION

Pain originating from the lumbar facets can be defined as pain that arises from the innervated structures comprising the joint: the subchondral bone, synovium, synovial folds, and joint capsule. Reported prevalence rates range from 4.8% to over 50% among patients with mechanical low back pain, with diagnosis heavily dependent on the criteria employed. In well-designed studies, the prevalence is generally between 10% and 20%, increasing with age.

METHODS

The literature on the diagnosis and treatment of lumbar facet joint pain was retrieved and summarized.

RESULTS

There are no pathognomic signs or symptoms of pain originating from the lumbar facet joints. The most common reported symptom is uni- or bilateral (in more advanced cases) axial low back pain, which often radiates into the upper legs in a non-dermatomal distribution. Most patients report an aching type of pain exacerbated by activity, sometimes with morning stiffness. The diagnostic value of abnormal radiologic findings is poor owing to the low specificity. SPECT can accurately identify joint inflammation and has a predictive value for diagnostic lumbar facet injections. After "red flags" are ruled out, conservatives should be considered. In those unresponsive to conservative therapy with symptoms and physical examination suggesting lumbar facet joint pain, a diagnostic/prognostic medial branch block can be performed which remains the most reliable way to select patients for radiofrequency ablation.

CONCLUSIONS

Well-selected individuals with chronic low back originating from the facet joints may benefit from lumbar medial branch radiofrequency ablation.

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.

Does medial branch radiofrequency neurotomy accelerate degenerative lumbar spondylolisthesis compared to natural progression? A cross-sectional cohort study

Background

Lumbar radiofrequency neurotomy (LRFN) effectively treats lumbar zygapophyseal joint pain by coagulating medial branch nerves (MBNs) carrying nociceptive signals. MBNs also innervate deep paraspinal muscles. There is a paucity of literature on whether LRFN accelerates the progression of vertebral displacement in patients with degenerative lumbar spondylolisthesis (DLS).

Objective

Compare the rate of spondylolisthesis progression in adults with DLS who underwent LRFN to the 2% annual rate of progression expected by natural history.

Design

Cross-sectional cohort study.

Methods

Consecutive patients with pre-existing DLS who underwent LRFN for zygapophyseal joint-mediated low back pain were identified. Patient demographics, LRFN procedure details, and radiographic images confirming Meyerding Grade (I-II) spondylolisthesis were collected from electronic medical records. The quantitative magnitude of spondylolisthesis progression and the annualized rate were calculated from pre-and post-LRFN radiographs. Data were analyzed using Wilcoxon signed-rank tests and a linear regression model.

Results

152 patients (mean age 65.9 ± 12.3 years; 59.2% female) met eligibility criteria and were included in the analyses. Average time to radiographic follow-up was 35.6 ± 24.7 months post-LRFN. The average spondylolisthesis progression rate of 1.63 ± 2.91% per year calculated for the LRFN cohort was significantly lower than the 2% annual rate of progression associated with natural history (p < 0.001). None of the included covariates, such as age, BMI, LRFN laterality, number of levels denervated, or history of prior lumbar spinal surgery, were significantly associated with the average annual rate of progression.

Conclusions

Our results suggest that spondylolisthesis progression rate is no different or worse than the expected natural progression rate in patients with pre-existing DLS who have undergone LRFN.

FactFinders for patient safety: Understanding potential procedure-related complications: RFN/multifidus atrophy, intradiscal biologics, and facet cyst rupture

This series of FactFinders presents a brief summary of the evidence and outlines recommendations to improve our understanding and management of several potential procedure-related complications. The evidence in support of the following facts is presented: (1) Multifidus Atrophy After Lumbar Medial Branch Radiofrequency Neurotomy (LMBRFN) -- There is no conclusive published literature indicating that LMBRFN leads to increased multifidus atrophy relative to natural history. High-quality prospective studies with a natural history comparison group evaluating immediate pre-procedure as well as post-procedure longitudinal cross-sectional imaging are needed to accurately assess for any possible influence of LMBRFN on multifidus atrophy as well as the clinical relevance. (2) Intradiscal Biologics -- Although the available evidence on intradiscal biologic interventions is limited, it nonetheless shows a non-zero risk of complications. Until larger sample sizes are reported, the actual magnitude of the risk cannot be ascertained. In the meantime, physicians who perform intradiscal injections of biologics should conscientiously consider the risk-benefit of these procedures. (3) Lumbar Facet Synovial Cyst Rupture -- There have been few reports of complications secondary to lumbar facet synovial cyst rupture. Risks of may include increased pain, infection, and nerve root compression.

Quantification of Needle Angles for Traditional Lumbar Medial Branch Radiofrequency Ablation: An Osteological Study

BACKGROUND

Clinical outcomes following lumbar medial branch radiofrequency ablation (RFA) have been inconsistent. One possible reason is less-than-optimal placement of the electrode along the medial branch at the lateral neck of superior articular process (SAP). Needle angles that define optimal placement (i.e., parallel to the medial branch) may be helpful for consistent technical performance of RFA. Despite its importance, there is a lack of anatomical studies that quantify RFA needle placement angles.

OBJECTIVE

To quantify and compare needle angles to achieve parallel placement along the medial branch as it courses on the middle two-quarters of the lateral neck of the SAP at the L1-L5 vertebrae.

DESIGN

Osteological Study.

METHODS

Ten lumbar vertebral columns were used in this study. Needles were placed along the periosteum of the middle two-quarters of the lateral neck of SAP. Mean needle angles for L1-L5 were quantified and compared using posterior (n = 100) and lateral (n = 100) photographs.

RESULTS

Mean needle angles varied ranging from 29.29 ± 17.82° to 47.22 ± 16.27° lateral to the parasagittal plane (posterior view) and 33.53 ± 10.23° to 49.19 ± 10.69° caudal to the superior vertebral endplate (lateral view). Significant differences in mean angles were found between: L1/L3 (P = .008), L1/L4 (P = .003), and L1/L5 (P = .040) in the posterior view and L1/L3 (P = .042), L1/L4 (P < .001), L1/L5 (P < .001), L2/L4 (P = .004), and L2/L5 (P = .004) in lateral view.

CONCLUSIONS

Variability of needle angles suggest a standard "one-size-fits-all" approach may not be the optimal technique. Future research is necessary to determine optimal patient-specific needle angles from a more detailed and granular analysis of fluoroscopic landmarks.

Abnormal Paresthesias Associated With Radiofrequency Ablation of Lumbar Medial Branch Nerves: A Case Report

Radiofrequency ablation (RFA) is an effective treatment that has occasionally been associated with transient paresthesias. This case report details an unusual presentation of paresthesias after lumbar medial branch RFA. A 48-year-old female patient reported pain, numbness, and swelling on the left buttock and posterolateral thigh. A physical exam revealed allodynia over the left posterolateral thigh without neurologic deficits two weeks after RFA of the left-sided lumbar medial branch nerves innervating the L4-L5 and L5-S1 facet joints. Shortly after the RFA of the contralateral targets, the patient complained of numbness of the right-sided lower back extending laterally from the right hip to the right knee. Imaging confirmed the appropriate placement of all needles in both procedures. Both instances of paresthesias resolved over time. This case report aims to demonstrate that RFA can be associated with unusual paresthesias and that these adverse effects do not warrant excessive workup.

Considerations for Lumbar Medial Branch Nerve Radiofrequency at Spinal Motion Segments Adjacent to a Fusion Construct

Instrumented lumbar spinal fusion is common and results in biomechanical changes at adjacent spinal segments that increase facet load bearing. This can cause facet-mediated pain at levels adjacent to the surgical construct. Medial branch nerve radiofrequency ablation (RFA) exists as a treatment for some cases. It is important to acknowledge that the approach and instrumentation used during some specific lumbar fusion approaches will disrupt the medial branch nerve(s). Thus, the proceduralist must consider the fusion approach when determining which medial branch nerves are necessary to anesthetize for diagnosis and then to potentially target with RFA. This article discusses the relevant technical considerations for preparing for RFA to denervate lumbosacral facet joints adjacent to fusion constructs.

First-Time Lumbar Medial Branch Radiofrequency Ablation: Patient-Reported Outcomes Measurement Information System as a Metric of Outcome

OBJECTIVE

To investigate the ability of Patient-Reported Outcomes Measurement Information System (PROMIS) to capture the therapeutic effect of first-time medial branch radiofrequency ablation (RFA).

DESIGN

Before-after trial.

SETTING

Single academic spine center.

PARTICIPANTS

Patients who underwent first-time medial branch RFA for lumbar facet joint pain identified by dual comparative medial branch block with ≥80% pain relief between January 1, 2015 and September 1, 2019 were identified using procedural billing codes. Charts were reviewed manually to confirm accuracy and strict adherence to the 80% pain relief threshold for each medial branch block. Thirty-nine patients met the criteria and were included in this study (N=39).

INTERVENTIONS

Medial branch RFA.

MAIN OUTCOME MEASURES

PROMIS score domains of Depression, Pain Interference, and Physical Function collected pre- and post RFA were compared. Pretreatment scores were within 6 weeks prior to the first medial branch block. Posttreatment scores were between 5 weeks and 6 months after RFA. Paired-sample t test analyses were used to calculate responsiveness to treatment, with significance assigned as P<.05 prior to acquiring data. Effect size was calculated using Cohen's d.

RESULTS

PROMIS domains of Pain Interference and Physical Function demonstrated a statistically significant improvement (P=.004 and P=.017, respectively). The PROMIS domain of Depression did not demonstrate a statistically significant change (P=.12). The effect size was medium (d=-0.43) for Pain Interference, small/medium (d=0.31) for Physical Function, and small (d=-0.12) for Depression.

CONCLUSIONS

Medial branch RFA as a treatment for lumbar facet syndrome is associated with a statistical improvement in PROMIS domains of Physical Function and Pain Interference.

Cost-effectiveness of radiofrequency neurotomy to treat zygapophysial joint pain compared with pain rehabilitation programs

Background

Chronic pain is a widespread condition that causes much suffering and significant cost to society. Pain rehabilitation programs (REH) have dominated the treatment of chronic pain in Sweden in recent decades. Although radiofrequency neurotomy (RFN) was cost-effective in recent studies, the long-term health and economic effects of REH have not been comprehensively evaluated.

Design

Observational study with propensity score weighting to compare RFN and REH.

Methods

Patients assessed and treated between 2010 and 2016 were eligible; 15,357 underwent REH and 254 underwent RFN. Patient data were combined with linked data from national registers. We used propensity score weighting to mimic a randomized controlled trial using baseline gender, age, and baseline health-related quality of life as covariates.

Results

Health-related quality of life improved significantly in both groups, by 0.164 and 0.352 quality-adjusted life years (QALYs) at 1 and 2 years after REH, and by 0.186 and 0.448 QALYs after RFN. The assessment and diagnostic procedures were slightly more expensive for RFN, but the treatment costs were greater for REH. Sick leave decreased after treatment in both groups, particularly after RFN. The cost per QALY gained 1 year after REH was ∼121,633 USD, which is considered "very expensive" according to the Swedish National Board of Health and Welfare. By comparison, the cost of RFN was ∼13,715 USD, in the "moderate" range. After 2 years the cost per QALY gained was in the "moderate" range for REH and "low" for RFN.

Conclusions

RFN and REH improved health-related quality of life, with significantly greater improvement with RFN. The treatments were comparable based on propensity score weighting, and RFN was cost-effective in the moderate to low range, whereas REH was considered very expensive to moderate. Expanding RFN from 2% currently to 25% of the treatments given in Sweden could save ∼21.2 million USD annually in healthcare expenditure.

Facet Joint Syndrome: Pathophysiology, Diagnosis, and Treatment

Facet joint osteoarthritis (OA) is the most frequent form of facet joint syndrome. Medical history, referred pain patterns, physical examination, and diagnostic imaging studies (standard radiographs, magnetic resonance imaging, computed tomography and single-photon emission computed tomography) may suggest but not confirm lumbar facet joint (LFJ) syndrome as a source of low back pain (LBP). However, the diagnosis and treatment of facet joint syndrome is still controversial and needs further study. It is widely acknowledged that block with local anesthetic is perhaps the most effective method to establish a diagnosis of pain from LFJ. Particularly, there are different rates of success among different populations selected for diagnostic block with various positive criteria. Currently, in addition to conservative treatments for pain such as painkillers, functional exercises, and massage, there are many other methods, including block, denervation of the nerves that innervate the joints by radiofrequency, freezing or endoscopy, and injections. Due to the limited duration of pain relief from neurolysis of medial branch, many scholars have recently turned their targets to dorsal roots and LFJ capsules. Therefore, we reviewed the latest research progress of facet joint syndrome from diagnosis to treatment.

Thermal Radiofrequency Ablation Combined with Corticosteroid Injection in Management of Lumbar Facet Joint Pain: A Single-Center Study in Vietnam

OBJECTIVE

We sought to evaluate the effectiveness of thermal radiofrequency ablation combined with corticosteroid injection for medial branch block in the management of chronic low back pain, which originates from lumbar facet joint (LFJ) pain.

METHODS

A prospective observational study of 82 patients with chronic LFJ pain undergoing thermal radiofrequency ablation combined with corticosteroid injection was conducted. Primary outcomes included pain relief and functional recovery, measured by the visual analog scale (VAS) and Oswestry Disability Index, respectively. Secondary outcome was the time of recurrent low back pain at the same spinal segment after treatment. Adverse events were also recorded.

RESULTS

Mean age is 55.7 ± 15.2 years old, and duration of LFJ pain was 18.2 ± 9.5 months. Median VAS at baseline was 7.0 (7.0-9.0) for all ages. After intervention, VAS and Oswestry Disability Index improved significantly (P < 0.001). Pain relief lasted for 1 month, 3 months, 6 months, 12 months, and 12-24 months' follow-up. During this period, only 5 patients required another radiofrequency neurotomy procedure (6.1%). No complications occurred in the study group.

CONCLUSIONS

Thermal radiofrequency ablation combined with corticosteroid injection should be a potential method of choice for its effectiveness, long-lasting effect, and safety in the management of LFJ pain.

The Relationship Between Patient Demographic and Clinical Characteristics and Successful Treatment Outcomes After Basivertebral Nerve Radiofrequency Ablation: A Pooled Cohort Study of Three Prospective Clinical Trials

OBJECTIVE

Multiple studies have demonstrated the safety and effectiveness of basivertebral nerve radiofrequency ablation (BVN RFA) for improving low back pain related to the vertebral endplate. However, the influence of patient demographic and clinical characteristics on treatment outcome is unknown.

DESIGN

Pooled cohort study of three clinical trials of patients with vertebral endplate pain identified by Type 1 and/or Type 2 Modic changes and a correlating presentation of anterior spinal element pain.

SETTING

Thirty-three global study centers.

SUBJECTS

Patients (n = 296) successfully treated with BVN RFA.

METHODS

Participant demographic and clinical characteristics were analyzed with stepwise logistic regression to identify predictors of treatment success. Three definitions of treatment success were defined: 1) ≥50% visual analog scale pain improvement, 2) ≥15-point Oswestry Disability Index (ODI) improvement, and 3) ≥50% visual analog scale or ≥15-point ODI improvement from baseline.

RESULTS

Low back pain of ≥5 years' duration and higher ODI scores at baseline increased the odds of treatment success, whereas baseline opioid use and higher Beck Depression Inventory scores reduced these odds. However, the three regression models demonstrated receiver-operating characteristics of 62-70% areas under the curve, and thus, limited predictive capacity.

CONCLUSIONS

This analysis identified no demographic or clinical characteristic that meaningfully increased or reduced the odds of treatment success from BVN RFA. On the basis of these findings and the high response rates from the three analyzed trials, we recommend the use of objective imaging biomarkers (Type 1 and/or 2 Modic changes) and a correlating presentation of anterior spinal element pain to determine optimal candidacy for BVN RFA.

The mechanism of action of pulsed radiofrequency in reducing pain: a narrative review

Pain from nervous or musculoskeletal disorders is one of the most common complaints in clinical practice. Corticosteroids have a high pain-reducing effect, and their injection is generally used to control various types of pain. However, they have various adverse effects including flushing, hyperglycemia, allergic reactions, menstrual changes, immunosuppression, and adrenal suppression. Pulsed radiofrequency (PRF) is known to have a pain-reducing effect similar to that of corticosteroid injection, with nearly no major side effects. Therefore, it has been widely used to treat various types of pain, such as neuropathic, joint, discogenic, and muscle pain. In the current review, we outlined the pain-reducing mechanisms of PRF by reviewing previous studies. When PRF was first introduced, it was supposed to reduce pain by long-term depression of pain signaling from the peripheral nerve to the central nervous system. In addition, deactivation of microglia at the level of the spinal dorsal horn, reduction of proinflammatory cytokines, increased endogenous opioid precursor messenger ribonucleic acid, enhancement of noradrenergic and serotonergic descending pain inhibitory pathways, suppression of excitation of C-afferent fibers, and microscopic damage of nociceptive C- and A-delta fibers have been found to contribute to pain reduction after PRF application. However, the pain-reducing mechanism of PRF has not been clearly and definitely elucidated. Further studies are warranted to clarify the pain-reducing mechanism of PRF.

Comparison of two needle versus one needle lesioning techniques for thoracic medial branch neurotomy

Background and objectives

No prior studies have investigated an assumed advantage of creating a radiofrequency strip lesion for posterior element spinal axial pain using a two-needle technique (TNT) compared to a one-needle technique (ONT) that creates a single ovoid lesion. We explore the relationship of TNT compared to ONT on the magnitude and duration of pain relief following thoracic medial branch neurotomy (TMBN).

Methods

This study is a retrospective audit of consecutive patients treated with TMBN at a single site and interventionalist over ten years (2007-2017). All patients had undergone TMBN after failed conservative care and, with few exceptions, patient-reported ≥ 70% pain relief after thoracic medial branch block (TMBB). All patients had TMBN performed with a medial to lateral (MLA) radiofrequency cannula approach using either an ONT or TNT technique. We used parametric and nonparametric statistics and three levels of case analysis to assess for intergroup differences.

Results

Thirty-five consecutive patients underwent their primary TMBN, and two underwent both on a subsequent repeat using the MLA approach, 19 using the ONT, 18 using the TNT. The TNT group had clinically and statistically greater pain relief magnitude and duration than the ONT subgroup. The difference resulted in non-overlapping 95% confidence intervals for both percent pain relief and duration of pain relief using three levels of case analysis.

Conclusion

The comparison of TMBN techniques demonstrates a statistically significant separation of TNT to ONT sample mean values for magnitude and duration of pain relief when using TNT compared to ONT for TMBN using an MLA.

A comparison of the effectiveness of cervical medial branch radiofrequency ablation for chronic facet joint syndrome in patients selected by two common medial branch block paradigms

Background

Cervical medial branch radiofrequency ablation (CMBRFA) is effective when patients are selected by dual medial branch blocks (MBBs). SIS guidelines recommend 100% pain improvement after dual comparative MBBs before CMBRFA; however, our prior investigation showed similar outcomes in those selected by a lesser strict paradigm.

Objective

Compare pain and patient impression of improvement after CMBRFA in individuals stratified by a less stringent (80-99%) dual MBB response than those selected by the 100% criteria.

Design

Cross-sectional study.

Methods

Follow-up was conducted via standardized telephone survey at ≥6 months post-CMBRFA to obtain Numerical Rating Scale (NRS) pain and Patient Global Impression of Change (PGIC) scores. Primary and secondary outcomes were within-group and between-group differences in the proportions of patients reporting ≥50% NRS score reduction and PGIC scores.

Results

Medical records of 195 consecutive patients were reviewed; 100 individuals were analyzed. 48% (95% CI 35-61%) and 52% (95% CI 37-67%) of the 80-99% and 100% MBB groups, reported ≥50% pain reduction at ≥6 months post-CMBRFA. 74% (95% CI 63-85%) and 67% (95% CI 52-81%) of the 80-99% and 100% MBB groups reported a PGIC score consistent with "improved" or "very much improved." There were no significant between-group differences in any outcome at any time point.

Conclusions

We observed similar rates of pain relief and global improvement after CMBRFA in patients selected by dual MBBs with ≥80% symptom relief versus 100% relief. This provides evidence that a more practical criteria, compared to a more strict selection paradigm, may result in similar clinical outcomes.

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.

Percutaneous Radiofrequency Ablation to Occlude the Thoracic Duct: Preclinical Studies in Swine for a Potential Alternative to Embolization

PURPOSE

To investigate the feasibility of percutaneous radiofrequency ablation (RFA) to occlude the thoracic duct (TD) in a swine model with imaging and histologic correlation.

MATERIALS AND METHODS

Six swine underwent TD RFA. Two terminal (4 hours; 1 open, 1 percutaneous) and four survival (30 days; all percutaneous) studies were performed. Two 20-gauge needles were placed adjacent to the TD under direct visualization after right thoracotomy or under fluoroscopic guidance using a percutaneous transabdominal approach after intranodal lymphangiography. Radiofrequency electrodes were advanced through the needles and ablation was performed at 90 degrees Celsius for 90 seconds. Lymphangiography was performed and the TD and adjacent structures were resected and examined microscopically at the end of each study period.

RESULTS

Four of six subjects survived the planned study period and underwent follow up lymphangiography. Two subjects in the survival group were euthanized early; 1 after developing an acute chylothorax and 1 due to gastric volvulus 14 days after ablation. Occlusion of the targeted TD segment was noted on lymphangiography in 3 of 4 remaining subjects (2 acute, 1 survival). Histology 4 hours after RFA demonstrated necrosis of the TD wall and hemorrhage within the lumen. Histology at 14 and 30 days revealed fibrosis with hemosiderin laden macrophages replacing the ablated TD. Collagen degeneration within the aortic wall involving a maximum of 60% thickness was noted in 5/6 subjects.

CONCLUSION

Percutaneous RFA can achieve short-segment TD occlusion. Further study is needed to improve safety and demonstrate clinical efficacy in treating TD leaks.

Lumbar medial branch block progression to radiofrequency neurotomy: A retrospective audit of clinical practice

Introduction

Chronic axial low back pain due to zygapophysial joint arthropathy is best diagnosed via lumbar medial branch block (MBB). However, the paradigm by which MBB is used to select patients for lumbar radiofrequency neurotomy (RFN) is contested. Dual diagnostic lumbar MBB with a minimum of ≥80% pain relief to diagnose lumbar zygapophysial joint pain are accepted by some Medicare Local Coverage Determination (LCD) as the method for selecting patients for RFN for the management of lumbar zygapophysial joint pain. However, some argue that dual diagnostic MBB and the ≥80% pain relief threshold lack utility in clinical practice, given that those that progress from MBB1 to MBB2 will then flow from MBB2 to RFN without fail.

Study

Pragmatic retrospective clinical audit.

Objective

Does clinical practice of dual diagnostic lumbar MBBs and an ≥80% pain improvement diagnostic threshold reduce patient eligibility for RFN after both MBB1 and MBB2?

Results

Using dual diagnostic lumbar MBBs and an ≥80% pain improvement diagnostic threshold, 90/167 (54%, 95% CI 46-61%) patients successfully progressed from MBB1 to MBB2. Of those 90 patients, 66 patients (73%, 95% CI 64-82%) successfully progressed from MBB2 to RFN. Both MBB1 and MBB2 impacted the eligibility of the progression of 77/167 (46%, 95% CI 39-54%) patients and 24/90 patients (27%, 95% CI 18-36%), respectively. An additional sub-cohort analysis which included all the patients from the ≥80% pain relief cohort, and those who progressed at the discretion of the providers with 50-79% relief revealed that 124/167 patients (74%, 95% CI 68-81%) successfully progressed from MBB1 to MBB2. Of those 124 patients, 99 patients (80%, 95% CI 73-87%) progressed from MBB2 to RFN. In this laxer criteria cohort, MBB1 and MBB2 impacted the eligibility of the progression of 43/167 patients (26%, 95% CI 19-32%) and 25/124 patients (20%, 95% CI 13-27%), respectively.

Conclusion

MBB1 and MBB2 both filtered patients from progression to lumbar RFN using dual MBBs with an ≥80% pain relief criteria. It also held true when using a more relaxed pain relief selection criterion as well. Dual MBB's and ≥80% pain improvement criteria as a selection paradigm led to half as many lumbar RFNs being performed when compared to a single MBB and ≥80% pain improvement criteria. In theory, a more rigid selection paradigm treats less patients but exposes fewer to unnecessary RFNs while a laxer selection paradigm treats more patients but exposes more to unnecessary RFNs.

Evaluation of an Ultrasound-Assisted Longitudinal Axis Lateral Crest Approach to Radiofrequency Ablation of the Sacroiliac Joint

OBJECTIVE

The aim of the study was to evaluate the effectiveness and procedural characteristics of a novel, ultrasound/fluoroscopically guided technique (longitudinal axis sacroiliac joint radiofrequency ablation) for sacroiliac joint denervation.

DESIGN

A single-arm cohort with historical cohort comparison was used in this study.

METHODS

Thirty-seven participants underwent longitudinal axis sacroiliac joint radiofrequency ablation after 50% or more pain reduction after diagnostic dual-block criterion. Outcomes were the proportion of participants with 50% or more pain reduction and mean Pain Disability Quality of Life Questionnaire change. Subanalysis included longitudinal axis sacroiliac joint radiofrequency ablation procedural and fluoroscopy times compared with participants previously treated with palisade radiofrequency ablation technique.

RESULTS

Primary outcome worst case analysis demonstrated a responder rate of 64.9% (95% confidence interval = 48.8%-78.2%) and 59.5% (95% confidence interval = 43.5%-73.7%) at 3 and 6 mos. There was significant decrease in mean Pain Disability Quality of Life Questionnaire at 3 (45.6 ± 9.5 to 21.4 ± 16.0, P < 0.001) and 6 mos (45.6 ± 9.5 to 23.0 ± 16.5, P < 0.001). Longitudinal axis sacroiliac joint radiofrequency ablation required more procedure time than the palisade technique (38.2 ± 7.9 vs. 32.1 ± 6.9 mins, P = 0.031) but less fluoroscopy time (35.0 ± 11.8 vs. 57.6 ± 16.8 secs, P < 0.001).

CONCLUSIONS

Longitudinal axis sacroiliac joint radiofrequency ablation resulted in improvement in pain, disability, and quality of life at 3 and 6 mos. Compared with the palisade technique, longitudinal axis sacroiliac joint radiofrequency ablation required greater procedure time but less fluoroscopy time.

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.

Predicting Treatment Success with Facet Syndrome: An Algorithm to Predict Lumbar Radiofrequency Ablation Responders in a Military Population

OBJECTIVE

Radiofrequency ablation (RFA) of the medial branch nerve is a commonly performed procedure for patients with facet syndrome. RFA has previously been demonstrated to provide long-term functional improvement in approximately 50% of patients, including those who had significant pain relief after diagnostic medial branch block. We sought to identify factors associated with success of RFA for facet pain.

DESIGN

Active-duty military patients who underwent lumbar RFA (L3, L4, and L5 levels) over a 3-year period were analyzed. Defense and Veterans Pain Rating Scale (DVPRS) and Oswestry Disability Index (ODI) scores were assessed the day of procedure and at the 2-month and 6-month follow-up. These data were analyzed to identify associations between patient demographics, pain, and functional status and patients' improvement after RFA, with a primary outcome of ODI improvement and a secondary outcome of pain reduction.

RESULTS

Higher levels of starting functional impairment (starting ODI scores of 42.9 vs. 37.5; P = 0.0304) were associated with a greater likelihood of improvement in functional status 6 months after RFA, and higher starting pain scores (DVPRS pain scores of 6.1 vs. 5.1; P < 0.0001) were associated with a higher likelihood that pain scores would improve 6 months after RFA. A multivariate logistic regression was then used to develop a scoring system to predict improvement after RFA. The scoring system generated a C-statistic of 0.764, with starting ODI, pain scores, and both gender and smoking history as independent variables.

CONCLUSIONS

This algorithm compares favorably to that of diagnostic medial branch block in terms of prediction accuracy (C-statistic of 0.764 vs. 0.57), suggesting that its use may improve patient selection in patients who undergo RFA for facet syndrome.

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.