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.

Normality Analysis of Numeric Rating Scale Scores in Patients with Chronic Axial Spine Pain Before and After Medial Branch Blocks: a Multicenter Study.

OBJECTIVE: The statistical analysis typically employed to compare pain both before and after interventions assumes scores are normally distributed. The present study evaluates whether Numeric Rating Scale (NRS), specifically the NRS-11, scores are indeed normally distributed in a clinically-relevant cohort of adults with chronic axial spine pain pre- and post-analgesic intervention. METHODS: Retrospective review from four academic medical centers of prospectively collected data from a uniform pain diary administered to consecutive patients after undergoing medial branch blocks. The pain diary assessed NRS-11 scores immediately pre-injection and at 12 different time points post-injection up to 48 hours. D'Agostino-Pearson tests were used to test normality at all time points. RESULTS: One hundred fifty pain diaries were reviewed and despite normally distributed pre-injection NRS-11 scores (K2 = 0.655, p = 0.72), all post-injection NRS-11 data was not normally distributed (K2 = 9.70- 17.62, p = 0.0001-0.008). CONCLUSIONS: Although the results of parametric analyses of NRS-11 scores are commonly reported in pain research, some properties of NRS-11 do not satisfy the assumptions required for these analyses. The data demonstrate non-normal distributions in post-intervention NRS-11 scores, thereby violating a key requisite for parametric analysis. We urge pain researchers to consider appropriate statistical analysis and reporting for non-normally distributed NRS-11 scores to ensure accurate interpretation and communication of these data. Practicing pain physicians should similarly recognize that parametric post-intervention pain score statistics may not accurately describe the data and should expect manuscripts to utilize measures of normality to justify the selected statistical methods.

Mitigating Factors in L4 and L5 Medial Branch Motor Stimulation During Radiofrequency Ablation.

PURPOSE OF REVIEW: Radiofrequency ablation (RFA) is a minimally invasive procedure for facet joint pain. The targets for the procedure are the medial branches of the dorsal spinal nerves which innervate the facet joints. Before RFA, patients undergo diagnostic meal branch blocks to ensure appropriate pain relief and confirm the utility of proceeding to RFA. The success of RFA relies heavily on procedural technique and accurate placement near the medial branch. RECENT FINDINGS: Motor testing is utilized in the lumbar region to assess the response of the multifidus and ensure proper placement of the RFA probe to prevent inadvertent damage to surrounding spinal anatomy. However, relying on motor responses in this area presents challenges given the frequency of lack of muscle twitching. Factors contributing to limited muscle twitch responses include muscle atrophy, excessive lordosis, facet arthropathy, local anesthetic use before ablation, and previous surgical neurotomy. These complexities highlight the challenges in ensuring precise motor stimulation during RFA. Despite these obstacles, accurate anatomical placement remains crucial. For RFA cases that prove challenging, relying on anatomical placement can be adequate to proceed with the procedure. Bridging knowledge gaps is vital for standardized practices and safer procedures. Further research is necessary to refine techniques, understand patient-specific factors, and enhance the efficacy of RFA in managing chronic lumbar facet joint pain.

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.

[Radiofrequency denervation of the spine and the sacroiliac joint : A systematic literature search according to GRADE with new German S3 guideline]. / Radiofrequenzdenervation der Wirbelsäule und des Iliosakralgelenks : Eine systematische Literaturrecherche nach GRADE mit neuer S3-Leitlinie.

BACKGROUND: This article summarizes the results of the German guideline on radiofrequency denervation of the facet joints and the sacroiliac joint. Evidence on the indications, test blocks and technical parameters are presented. OBJECTIVE: The aim is to avoid overtreatment and undertreatment, which is also of socioeconomic importance. MATERIAL AND METHOD: A systematic evaluation of the literature was carried out according to the grading of recommendations assessment, development and evaluation (GRADE) approach. A multidisciplinary guideline group has developed recommendations and statements. RESULTS: Statements and recommendations were given for 20 key questions. There was an 87.5% consensus for 1 recommendation and 100% consensus for all other recommendations and statements. The guideline was approved by all scientific medical societies involved. Specific questions included the value of the medical history, examination and imaging, the need for conservative treatment prior to an intervention, the importance of test blocks (medial branch block and lateral branch block), choice of imaging for denervation, choice of trajectory, the possibility to influence the size of the lesion, stimulation, the possibility of revision, sedation and decision support for patients with anticoagulants, metal implants and pacemakers and advice on how to avoid complications. CONCLUSION: Selected patients can benefit from well-performed radiofrequency denervation. The guideline recommendations are based on very low to moderate quality of evidence.

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.

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.

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.

Multifidus dysfunction and restorative neurostimulation: a scoping review.

OBJECTIVE: Chronic low back pain (CLBP) is multifactorial in nature, with recent research highlighting the role of multifidus dysfunction in a subset of nonspecific CLBP. This review aimed to provide a foundational reference that elucidates the pathophysiological cascade of multifidus dysfunction, how it contrasts with other CLBP etiologies and the role of restorative neurostimulation. METHODS: A scoping review of the literature. RESULTS: In total, 194 articles were included, and findings were presented to highlight emerging principles related to multifidus dysfunction and restorative neurostimulation. Multifidus dysfunction is diagnosed by a history of mechanical, axial, nociceptive CLBP and exam demonstrating functional lumbar instability, which differs from other structural etiologies. Diagnostic images may be used to grade multifidus atrophy and assess other structural pathologies. While various treatments exist for CLBP, restorative neurostimulation distinguishes itself from traditional neurostimulation in a way that treats a different etiology, targets a different anatomical site, and has a distinctive mechanism of action. CONCLUSIONS: Multifidus dysfunction has been proposed to result from loss of neuromuscular control, which may manifest clinically as muscle inhibition resulting in altered movement patterns. Over time, this cycle may result in potential atrophy, degeneration and CLBP. Restorative neurostimulation, a novel implantable neurostimulator system, stimulates the efferent lumbar medial branch nerve to elicit repetitive multifidus contractions. This intervention aims to interrupt the cycle of dysfunction and normalize multifidus activity incrementally, potentially restoring neuromuscular control. Restorative neurostimulation has been shown to reduce pain and disability in CLBP, improve quality of life and reduce health care expenditures.

Facets of facet joint interventions.

Facet joint (FJ) disease is a common cause of axial low back pain with many minimally invasive image-guided treatment options. This article discusses fluoroscopic and CT-guided intraarticular FJ injections, medial branch (MB) radiofrequency ablation (RFA), and lumbar facet synovial cyst (LFSC) aspiration, rupture, or fenestration. Additionally, the article will highlight medial branch blocks (MBBs) utilized to diagnose facet-mediated pain and to predict outcomes to RFA.

Multimodal treatment including lumbar facet joint denervation for severe low back pain in patients with neuromuscular disorders.

BACKGROUND: Severe low back pain (LBP) is an occasional complaint in patients with neuromuscular disorders (NMDs). Accurate diagnosis and treatment are required to manage LBP; however, the precise pathophysiology differs for each patient. This study aimed to evaluate the efficacy of lumbar facet joint denervation (FJD) and adjunctive modalities in the treatment of LBP in patients with NMD-associated kyphoscoliosis. METHODS: A total of 16 patients (22 sites) with NMD (bilateral, n = 6; unilateral, n = 10) and LBP treated with lumbar FJD were evaluated. The patients were divided into two groups: those treated with FJD alone (group 1) and those treated with multimodal treatment, including FJD along with radiofrequency ablation for sacroiliac joint pain, piriform muscle block, botulinum toxin injection into the paraspinal muscles, spinal cord stimulation, or any of their combinations (group 2). All patients were followed up for 48 weeks postoperatively. The two groups were compared with respect to the duration required for improvements in LBP by more than 50% (numerical rating scale ≤ 5). RESULTS: There was no significant difference between the groups regarding the age, duration since the onset of Parkinson's syndrome, and radiographic analysis. The effective period of improved pain was greater in group 2 than in group 1 (30.7 vs. 8.4 weeks, P < 0.01). CONCLUSIONS: Multimodal treatment including FJD is safe and relatively effective in patients with NMD-associated kyphoscoliosis. Hence, it is a potential substitute for conventional spinal fixation surgery, which has a higher risk of complications.

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.

Thoracic Zygapophysial Joint Thermal Neurotomy: A Cohort Revealing Additional Outcomes by Specific Joint Groupings.

OBJECTIVE: Thoracic spinal pain is common, and patients with this type of pain have limited therapeutic options. The cohort in this study received diagnostic intra-articular zygapophysial joint injections leading to thermal neurotomy to the medial branch nerves to demonstrate improved pain as well as physical and psychological function. DESIGN: A consecutive cohort from 2012 to 2018 with retrospective analysis of prospectively gathered data. SETTING: A private multidisciplinary pain clinic with referrals from primary care. RESULTS: Forty-six complete data sets from 39 patients were found using a pre-procedure and 3-month post-procedure questionnaire. Further follow-up results were found for the dual primary outcomes of duration of ≥50% relief using a numeric rating scale (NRS) for the entire group. The group was then divided into three subgroups of T1/2-T3/4, T4/5-T8/9, and T9/10-T12/L1. Success rates of 63% for ≥3 months of ≥50% relief and 46% for ≥6 months of ≥50% relief were found, for an average duration of 7.8 months. Group mean change in the NRS was 6.7, decreasing to 4.3 (P<0.0001). For the first time, there are data showing that the three groups of T1/2-T3/4, T4/5-T8/9, and T9/10-T12/L1 responded equally. Secondary outcomes of physical and psychological function using the Functional Rating Index (FRI) and the Depression Anxiety Stress Scale (DASS) all showed significant improvements with small to moderate effect sizes and with all achieving >36% improvement in scores. CONCLUSION: This cohort demonstrates that there is a pragmatic diagnostic and therapeutic option available for patients with thoracic zygapophysial joint pain that can achieve 50-100% of pain relief in 63% of patients with improved physical and psychological function.

Treatment of chronic axial back pain with 60-day percutaneous medial branch PNS: Primary end point results from a prospective, multicenter study.

BACKGROUND: The objective of this prospective, multicenter study is to characterize responses to percutaneous medial branch peripheral nerve stimulation (PNS) to determine if results from earlier, smaller single-center studies and reports were generalizable when performed at a larger number and wider variety of centers in patients recalcitrant to nonsurgical treatments. MATERIALS & METHODS: Participants with chronic axial low back pain (LBP) were implanted with percutaneous PNS leads targeting the lumbar medial branch nerves for up to 60 days, after which the leads were removed. Participants were followed long-term for 12 months after the 2-month PNS treatment. Data collection is complete for visits through end of treatment with PNS (primary end point) and 6 months after lead removal (8 months after start of treatment), with some participant follow-up visits thereafter in progress. RESULTS: Clinically and statistically significant reductions in pain intensity, disability, and pain interference were reported by a majority of participants. Seventy-three percent of participants were successes for the primary end point, reporting clinically significant (≥30%) reductions in back pain intensity after the 2-month percutaneous PNS treatment (n = 54/74). Whereas prospective follow-up is ongoing, among those who had already completed the long-term follow-up visits (n = 51), reductions in pain intensity, disability, and pain interference were sustained in a majority of participants through 14 months after the start of treatment. CONCLUSION: Given the minimally invasive, nondestructive nature of percutaneous PNS and the significant benefits experienced by participants who were recalcitrant to nonsurgical treatments, percutaneous PNS may provide a promising first-line neurostimulation treatment option for patients with chronic axial back pain.

An incoherent HIFU transducer for treatment of the medial branch nerve: Numerical study and in vivo validation.

BACKGROUND: Chronic back pain due to facet related degenerative changes affects 4-6 million patients a year in the United States. Patients refractory to conservative therapy may warrant targeted injections of steroids into the joint or percutaneous medial branch nerve denervation with radiofrequency ablation. We numerically tested a novel noninvasive high intensity focused ultrasound transducer to optimize nerve ablation near a bone-soft tissue interface. METHODS: A transducer with 4 elements operating in an incoherent mode was modeled numerically and tested pre-clinically under fluoroscopic guidance. After 6 lumbar medial branch nerve ablations were performed in 2 pigs, they were followed clinically for 1 week and then sacrificed for pathological evaluation. RESULTS: Simulations show that the acoustic spot size in water at 6 dB was 14mm axial x 1.6mm lateral and 52mm axial x 1.6mm lateral for coherent and incoherent modes, respectively. We measured the size of N = 6 lesions induced in vivo in a pig model and compared them to the size of the simulated thermal dose. The best match between the simulated and measured lesion size was found with a maximum absorption coefficient in the cortical bone adjusted to 30 dB/cm/MHz. This absorption was used to simulate clinical scenarios in humans to generate lesions with no potential side effects at 1000 and 1500 J. CONCLUSION: The elongated spot obtained with the incoherent mode facilitates the targeting during fluoroscopic-guided medial branch nerve ablation.

The Effectiveness of Cervical Medial Branch Radiofrequency Ablation for Chronic Facet Joint Syndrome in Patients Selected by a Practical Medial Branch Block Paradigm.

BACKGROUND: Cervical medial branch radiofrequency ablation (CMBRFA) is an effective treatment for facetogenic pain in patients selected by Spine Intervention Society (SIS) guidelines of 100% symptom improvement with dual medial branch blocks (MBBs) ± placebo block. Patient selection for CMBRFA using ≥80% symptom improvement after dual concordant MBBs is common; however, this has not been studied. OBJECTIVE: To evaluate the effectiveness of CMBRFA and compare outcomes in individuals selected by 80-99% vs 100% symptom improvement with dual concordant MBBs. DESIGN: Cross-sectional cohort study. METHODS: Medical records of 87 consecutive patients were reviewed; 50 met inclusion criteria. A standardized telephone survey was performed at six or more months post-CMBRFA to query numerical rating scale (NRS) pain and patient global impression of change (PGIC) scores. The primary outcomes were the proportion of patients reporting ≥50% reduction of index pain. RESULTS: At a mean follow-up time of 16.9 ± 12.7 months, 54% (95% confidence interval [CI] = 35-73%) and 54% (95% CI = 32-74%) of the 80-99% and 100% MBBs groups, respectively, reported ≥50% pain reduction. Between-group comparison showed a relative risk of 0.99 (95% CI = 0.59-1.66) for meeting the primary outcome. Seventy percent (95% CI = 56-81%) of patients reported a PGIC score consistent with "improved or very much improved" at follow-up. CONCLUSIONS: CMBRFA is an effective treatment in patients who report ≥80% symptom relief with dual concordant MBBs. The present study demonstrated an overall ≥50% pain reduction rate of 54% and no significant difference between those selected by 80-99% vs 100% symptom relief with dual concordant MBBs.

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

OBJECTIVES: The lumbar medial branch nerve has historically been a focus for ablative techniques in the treatment of chronic low back pain (CLBP) of facetogenic origin. Recent developments in the field of neuromodulation have been employed to target these nerves for analgesia and/or functional restoration in broader populations of CLBP patients. The objective of this article was to provide an introductory review of procedural techniques and devices employed for peripheral nerve stimulation (PNS) of the lumbar medial branch of the dorsal ramus for the treatment of CLBP. METHODS: A literature search via PubMed.gov was performed through September 2019 with key words focusing on peripheral nerve stimulation for chronic low back pain. This was refined to include only those articles that focused specifically on stimulation of the lumbar medial branch of the dorsal ramus. References within selected articles and unpublished data currently in the peer review process were also utilized. RESULTS: Ninety articles from PubMed.gov were obtained. Two approaches to PNS of the medial branch of the dorsal ramus were identified. CONCLUSIONS: Our review of the current literature regarding techniques for neuromodulation of the medial branch of the dorsal ramus revealed two dominant methods: a temporarily implanted percutaneous coiled-lead approach and a permanently implanted system. The two techniques share some similarities, such as targeting the medial branch of the dorsal ramus, and also have some differences, such as indwelling time, stimulation parameters, duration of treatment, image guidance, and degrees of invasiveness, but they are both demonstrating promising results in clinical trials.

Systematic Review of the Effectiveness of Lumbar Medial Branch Thermal Radiofrequency Neurotomy, Stratified for Diagnostic Methods and Procedural Technique.

OBJECTIVE: To determine the effectiveness of lumbar medial branch thermal radiofrequency neurotomy based on different selection criteria and procedural techniques. DESIGN: Comprehensive systematic review. METHODS: A comprehensive literature search was conducted, and all authors screened and evaluated the studies. The Grades of Recommendation, Assessment, Development, and Evaluation system was used to assess all eligible studies. OUTCOME MEASURES: The primary outcome measure assessed was the success rate of the procedure, defined by varying degrees of pain relief following neurotomy. Data are stratified by number of diagnostic blocks and degree of pain relief, as well as procedural technique with perpendicular or parallel placement of electrodes. RESULTS: Results varied by selection criteria and procedural technique. At six months, 26% of patients selected via single medial branch block with 50% pain relief and treated via perpendicular technique achieved at least 50% pain relief; 49% of patients selected via dual medial branch blocks with 50% pain relief and treated via parallel technique achieved at least 50% pain relief. The most rigorous patient selection and technique-two diagnostic medial branch blocks with 100% pain relief and parallel electrode placement-resulted in 56% of patients experiencing 100% relief of pain at six months. CONCLUSIONS: This comprehensive systematic review found differences in the effectiveness of lumbar medial branch radiofrequency neurotomy when studies were stratified by patient selection criteria and procedural technique. The best outcomes are achieved when patients are selected based on high degrees of pain relief from dual medial branch blocks with a technique employing parallel electrode placement.

Multiple injections for low back pain: What's the future?

AIMS: To examine the strength of evidence available for multiple facet joint injections (FJIs) and medial branch blocks (MBBs), and to report on the variations in the NHS England framework using the getting it right first time (GIRFT) data. METHODS: Systematic review using patient, intervention, comparison, outcome and study strategy. The literature search using Cochrane, MEDLINE and EMBASE databases using MeSH terms: lumbar spine, spinal injection and facet joint ("Appendix A"). RESULTS: Three studies were identified that investigated the efficacy of multiple FJIs or MBBs. None of these studies reported sustained positive outcomes at long-term follow-up. CONCLUSION: There is a paucity of levels I and II evidence available for the efficacy of multiple FJIs and MBBs in treating low back pain. GIRFT data show a high degree of variation in the use of multiple FJIs, which would not be supported by the literature. These slides can be retrieved under Electronic Supplementary Material.

Intra-articular Steroids vs Saline for Lumbar Z-Joint Pain: A Prospective, Randomized, Double-Blind Placebo-Controlled Trial.

OBJECTIVE: To determine if intra-articular (IA) injection of corticosteroids is effective in reducing the need for radiofrequency ablation (RFA) in those with dual comparative medial branch block (MBB)-confirmed lumbar z-joint pain. DESIGN: This was a randomized, double blind, placebo-controlled study. SETTING: Two academic medical centers. SUBJECTS: Fifty-six consecutive subjects who had ≥80% pain relief during an initial screening MBB were recruited. METHODS: Patients received a second confirmatory MBB and concurrent IA injection of either corticosteroid or saline per randomization. Twenty-nine of 56 received intra-articular corticosteroid (triamcinolone 20 mg), of whom 24 also had a positive confirmatory MBB per Spine Interventional Society guidelines, with ≥80% pain relief from both MBBs. Twenty-seven of 56 received IA saline into the z-joint during the confirmatory MBB, of whom 22 also had a positive confirmatory MBB. The primary outcome measure was the categorical need for RFA due to insufficient pain relief with intra-articular injection, and the secondary outcome was time to RFA. RESULTS: There was no statistically significant difference in the need for an RFA between the groups (16/24 steroid, 67%, 95% confidence interval [CI] = 47-82%) vs 15/22 saline (68%, 95% CI = 47-84%, P = 1.00). The average time to RFA was also not different, at 6.00 weeks for steroids vs 6.55 weeks for saline (P = 0.82). CONCLUSIONS: Intra-articular corticosteroids were not effective in reducing the need for or the time to a radiofrequency ablation of the medial branches in those with dual MBB-confirmed lumbar z-joint pain.