Medial Branch Blocks Research Articles

Resolution of Long Standing Tinnitus Following Radiofrequency Ablation of C2-C3 Medial Branches – A Case Report

Tinnitus is described as an auditory phantom perception analogous to central neuropathic pain. Despite the high prevalence of this debilitating symptom, no intervention is recognized that reliably eliminates tinnitus symptoms; a cause has yet to be determined. A 65-year-old healthy man presented with a 3 year history of left-sided tinnitus. Full workup performed by the primary care physician including blood tests for electrolyte imbalance, consultations by 2 independent otholaryngologists, and imaging did not reveal abnormalities to provide etiology of the tinnitus. No other complaints were noted except for occasional minimal left sided neck pain. Cervical spine x-ray showed degenerative changes with facet hypertrophy more pronounced on the left side. Subsequently, the patient underwent diagnostic left-sided C2-C3 medial branch block, resulting in complete resolution of tinnitus for more than 6 hours. After successful radiofrequency ablation of left C2-C3 medial branches, the patient became asymptomatic. At one year follow-up, he continued to be symptom free. Sparce studies have shown interaction between the somatosensory and auditory system at dorsal cochlear nucleus (DCN), inferior colliculus, and parietal association areas. Upper cervical nerve (C2) electrical stimulation evokes potentials in the DCN, eliciting strong patterns of inhibition and weak excitation of the DCN principal cells. New evidence demonstrated successful transcutaneous electrical nerve stimulation (TENS) of upper cervical nerve (C2) for treatment of somatic tinnitus in 240 patients. This case indicates that C2-C3 facet arthropathy may cause tinnitus and radiofrequency ablation of C2-C3 medial branches can provide an effective approach not previously considered. Key words: Radiofrequency ablation, tinnitus, neuropathic pain, cervical medial branch block, cervical pain, auditory phantom perception

A Prospective Validation of Biplanar Ultrasound Imaging for C5-C6 Cervical Medial Branch Blocks

Ultrasound (US) guidance offers an alternative to fluoroscopy for medial branch blocks of the upper cervical spine, but it may be less accurate for blocks at the C5 and C6 levels. We hypothesized that a modified technique using biplanar US imaging would facilitate level identification and provide greater accuracy for the lower cervical spine. Forty patients with chronic neck pain underwent US-guided blocks of the C5 and C6 medial branches. For each level, 0.3 mL of a local anesthetic/iodinated contrast mixture was injected. Posterolateral in-plane needle placement was carried out in a transverse view, and the position of the needle tip was verified in the coronal plane using the C7 transverse process as a sonographic landmark. Contrast distribution, as assessed by a blinded observer on anteroposterior and lateral x-ray views, constituted the primary outcome. Secondary outcomes were performance time and pain relief 30 minutes after the blocks. One hundred percent and 97.5% of C5 and C6 levels, respectively, demonstrated appropriate contrast distribution. The C7 transverse process was readily identified in the coronal plane in all but 2 subjects. Performance time was 248.8 ± 82.7 seconds; the mean percentage of relief provided by the blocks was 76.9% ± 25.5%. In 30% of patients, a blood vessel was visualized crossing the C6 articular pillar and successfully avoided during needle insertion. Ultrasound guidance using a biplanar approach is a reliable imaging modality for C5 and C6 medial branch blocks.

Spinal interventions under ultrasound guidance

Injection therapies play important roles in the management of spinal pain and it has been preferred that they be performed under the guidance of computed tomography or fluoroscopy. Recently, several ultrasound-guided techniques for alleviating spinal pain have been introduced due to visualization of the inner structures, portability, and lack of radiation exposure. For the cervical spine, ultrasound-guided procedures including the nerve root block, facet joint injection, and medial branch block have shown successful results, and for the lumbar spine, so do the interventions including the interlaminar epidural block, nerve root block, facet joint injection, and medial branch block. However, ultrasonographically guided procedures have some limitations in that they cannot completely avoid unintentional intravascular injection and identify the spread pattern of injected solution underneath the bony structures. New and untried techniques to overcome these limitations are expected. This paper reviews a variety of techniques under ultrasound guidance that have been reported for injection therapy in the cervical and lumbar spine.

Nonoperative interventions for spinal pain

Spinal pain is a common symptom that motivates visiting a physician. However, the natural course is usually benign and few patients need invasive treatment. Even though history taking, neurological examination, and imaging studies provide useful information for understanding the etiology of spinal pain, the pain chart is the most important tool for decision making regarding spinal interventions. Invasive treatments for chronic spinal pain refractory to conservative management include surgery as well as established interventions such as medial branch blocks, nerve root blocks, the sacroiliac joint block, and radiofrequency neurotomy, as well as emerging procedures such as pressure-controlled discography and percutaneous epidural adhesiolysis. Surgery should be considered for patients with a progressive neurologic deficit including significant radiculopathy, failure of spinal interventions, or an uncertain or serious diagnosis.

Comparison of Lidocaine and Bupivacaine in Lumbar Medial Branch Block

Comparison of Lidocaine and Bupivacaine in Lumbar Medial Branch Block

Two-Year Follow-Up Results of Fluoroscopic Cervical Epidural Injections in Chronic Axial or Discogenic Neck Pain: A Randomized, Double-Blind, Controlled Trial

Study Design: A randomized, double-blind, active-controlled trial.Objective: To assess the effectiveness of cervical interlaminar epidural injections of local anesthetic with or without steroids for the management of axial or discogenic pain in patients without disc herniation, radiculitis, or facet joint pain.Summary of Background Data: Cervical discogenic pain without disc herniation is a common cause of suffering and disability in the adult population. Once conservative management has failed and facet joint pain has been excluded, cervical epidural injections may be considered as a management tool. Despite a paucity of evidence, cervical epidural injections are one of the most commonly performed nonsurgical interventions in the management of chronic axial or disc-related neck pain.Methods: One hundred and twenty patients without disc herniation or radiculitis and negative for facet joint pain as determined by means of controlled diagnostic medial branch blocks were randomly assigned to one of the 2 treatment groups. Group I patients received cervical interlaminar epidural injections of local anesthetic (lidocaine 0.5%, 5 mL), whereas Group II patients received 0.5% lidocaine, 4 mL, mixed with 1 mL or 6 mg of nonparticulate betamethasone.The primary outcome measure was ≥ 50% improvement in pain and function. Outcome assessments included numeric rating scale (NRS), Neck Disability Index (NDI), opioid intake, employment, and changes in weight.Results: Significant pain relief and functional improvement (≥ 50%) was present at the end of 2 years in 73% of patients receiving local anesthetic only and 70% receiving local anesthetic with steroids. In the successful group of patients, however, defined as consistent relief with 2 initial injections of at least 3 weeks, significant improvement was illustrated in 78% in the local anesthetic group and 75% in the local anesthetic with steroid group at the end of 2 years. The results reported at the one-year follow-up were sustained at the 2-year follow-up.Conclusions: Cervical interlaminar epidural injections with or without steroids may provide significant improvement in pain and functioning in patients with chronic discogenic or axial pain that is function-limiting and not related to facet joint pain.

Anatomical analysis of medial branches of dorsal rami of cervical nerves for radiofrequency thermocoagulation.

Cervical medial branch blocks are used to treat patients with chronic neck pain. The aim of this study was to clarify the anatomical aspects of the cervical medial branches to improve the accuracy and safety of radiofrequency denervation. Twenty cervical specimens were harvested from 20 adult cadavers. The anatomical parameters of the C4-C7 cervical medial branches were measured. The 3-dimensional computed tomography reconstruction images of the bone were also analyzed. Based on cadaveric analysis, most of the cervical dorsal rami gave off 1 medial branch; however, the cervical dorsal rami gave off 2 medial branches in 27%, 15%, 2%, and 0% at the vertebral level C4, C5, C6, and C7, respectively. The diameters of the medial branches varied from 1.0 to 1.2 mm, and the average distance from the notch of inferior articular process to the medial branches was about 2 mm. Most of the bifurcation sites were located at the medial side of the posterior tubercle of the transverse process. On the analysis of 3-dimensional computed tomography reconstruction images, cervical medial branches (C4 to C6) passed through the upper 49% to 53% of a line between the tips of 2 consecutive superior articular processes (anterior line). Also, cervical medial branches passed through the upper 28% to 35% of a line between the midpoints of 2 consecutive facet joints (midline). The present anatomical study may help improve accuracy and safety during radiofrequency denervation of the cervical medial branches.

Can changes in vital signs be used to predict the response to lumbar facet blocks and radiofrequency denervation? A prospective, correlational study.

Facet joint radiofrequency (RF) ablation is characterized by a high failure rate, which is partly due to the fact that pain relief after diagnostic blocks is inherently subjective. An area that has yet to be explored is whether more objective measures, such as changes in vital signs after blocks, might be used to predict treatment outcomes. A multicenter, prospective study was performed in 223 patients who underwent diagnostic lumbar medial branch blocks, of whom 87 proceeded to RF denervation. Blood pressure (BP), heart rate (HR), and pain scores were recorded preblock and 20 minutes postblock. A positive vital sign response was designated as a decrease of less than 7.5 units in BP or HR, and a positive facet block as pain relief of 50% or greater based on 6-hour pain diary scores. Overall, 125 subjects (56.1%; 95% confidence interval, 49.3%-62.6%) experienced a positive facet block, and 71 had 3-month follow-up information after denervation. Correlations between changes in NRS scores and HR (r = -0.01, P = 0.893), systolic BP (r = 0.05, P = 0.47), diastolic BP (DBP) (r = 0.08, P = 0.22), and mean arterial pressure (r = 0.08, P = 0.21) were weak and nonsignificant. No associations were found between facet block results and any vital sign. Six (85.7%) of 7 patients who experienced a decrease in DBP of greater than 7.5 mm Hg after facet block had a positive RF denervation outcome at 3 months, compared with 43.8% who did not (odds ratio, 7.52; 95% confidence interval, 0.84-363.8; P = 0.049). A classification tree based on significant decrease in DBP, pain duration, and baseline NRS pain score showed a 76.7% (range, 65.8%-86.3%) accuracy rate. Although a decrease in DBP of more than 7.5 mm Hg had 97.3% specificity and 85.7% positive predictive value for predicting positive RF ablation outcomes, the low negative predictive value (56.3%) precludes its use as a solitary screening tool. An algorithm based on age, baseline NRS pain score, and a significant decrease in DBP was able to predict 76.7% (range, 65.8%-86.3%) of RF denervation outcomes.

Vasovagal Rates in Flouroscopically Guided Interventional Procedures: A Study of Over 8,000 Injections

To determine the rate of vasovagal (vv) complications in fluoroscopically guided interventional procedures. Retrospective case series analysis of prospectively collected data from March 8, 2004 to January 30, 2009. A single academic medical center. Four thousand one hundred eighty-three subjects undergoing 8,010 consecutive injections. Pearson's chi-square test was used to determine the relationship between categorical variables. A total of 8,010 injections, including epidural steroid injections, radiofrequency nerve ablations, medial branch blocks, hip injections, knee injections, and glenohumeral injections were performed. Overall vv reaction rate was 2.6%, with 0.8% of procedures resulting in early terminated due to vv reaction. Peripheral joint injections had a vv rate of 0.2%, all occurring in hip injections. Transforaminal epidural steroid injections had a vv rate of 3.5%. Diagnostic blocks of the medial branches had the highest rate of vv (5.1%). Other predictors of vv reactions were identified including preprocedure pain score visual analog scale <5 (P = 0.004), male gender (P < 0.001), and age less than 65 years old (P < 0.001). vv reactions have an overall low occurrence rate (2.6%) in interventional procedures ranging from 0% in peripheral knee and shoulder injections to 5.1% in medial branch blocks. Conservative treatment of vv reaction and willingness to terminate procedures resulted in no serious adverse events related to vv reaction in 8,010 procedures.

Indications for Repeat Diagnostic Medial Branch Nerve Blocks Following a Failed First Medial Branch Nerve Block

No studies have directly measured the false negative rate of medial branch block (MBB) with correlation to medial branch neurotomy (MBN) outcome. We investigated the potential false negative MBB rate and the subsequent MBN outcome on a consecutive audit of all patients undergoing a double MBB protocol. We prospectively collected audit data and retrospectively collected data by phone on 229 consecutive patients undergoing diagnostic MBB. One-hundred-twenty-two patients reporting greater than 50% of subjective pain relief subsequently underwent either MBN or a confirmatory block followed by MBN. A total of 55 patients underwent a second confirmatory MBB and within that group 27.3% (15/55) reported less than 50% relief post initial MBB and 30.9% (17/55) between 50% and 69% relief. We performed an in-depth analysis of these 2 subgroups focusing on the reason a second MBB was performed despite a “negative” or “indeterminant” first MBB. We divided the “negative” responders to the first MBB into those reporting &lt; 50% relief (Group 1) and those reporting between 50% and 69% relief (Group 2). We calculated a potential 46.7% false negative rate in Group 1 and 47.1% false negative in Group 2; however, the false negative results in Group 1 were predominately in those patients reporting delayed relief of pain and those re-blocked greater than 2 years after the first MBB. The success rate in all patients undergoing MBN was 87% compared to the 75% relief in the false negative groups with no statistically significant difference. In summary, the false negative rate for patients reporting less than 50% relief post MBB is probably less than 20% although there is a high “apparent negative” responds in patients reporting delayed relief or in those who had a second block 2 or more years post initial MBB. Patients reporting between 50 and 69% pain relief have a false negative response rate of 47.1% and should be considered for a confirmatory block. Key words: Facet rhizotomy, zygapophyseal joint, low back pain, chronic pain, facet joint, radiofrequency neurotomy, medial branch block, medial branch neurotomy

Frequency of Discordance between Facet Joint Activity on Technetium Tc99m Methylene Diphosphonate SPECT/CT and Selection for Percutaneous Treatment at a Large Multispecialty Institution

The clinical impact of facet joint bone scan activity is not fully understood. The hypothesis of this study is that facet joints targeted for percutaneous treatment in clinical practice differ from those with reported activity on technetium Tc99m methylene diphosphonate SPECT/CT. All patients with a technetium Tc99m methylene diphosphonate SPECT/CT scan of the lumbar or cervical spine who underwent subsequent percutaneous facet joint steroid injection or comparative medial branch blocks at our institution between January 1, 2008, and February 19, 2013, were identified. Facet joints with increased activity were compared with those treated. A chart review characterized the clinical reasons for treatment discrepancies. Of 74 patients meeting inclusion criteria, 52 (70%) had discrepant imaging findings and treatment selection of at least 1 facet joint, whereas 34 patients (46%) had a side (right vs left) discrepancy. Only 92 (70%) of 132 facet joints with increased activity were treated, whereas 103 (53%) of 195 of treated facet joints did not have increased activity. The most commonly documented clinical rationale for discrepancy was facet joint activity that was not thought to correlate with clinical findings, cited in 18 (35%) of 52 patients. Facet joints undergoing targeted percutaneous treatment were frequently discordant with those demonstrating increased technetium Tc99m methylene diphosphonate activity identified by SPECT/CT at our institution, in many cases because the active facet joint(s) did not correlate with clinical findings. Further prospective double-blinded investigations of the clinical significance of facet joint activity by use of technetium Tc99m methylene diphosphonate SPECT/CT and comparative medial branch blocks are needed.

A Randomized, Double-Blind, Placebo-Controlled, Prospective Study of Intra-Articular Lumbar Zygapophysial Joint Corticosteroid Injection(s) as Treatment of Chronic Low Back Pain in a Selected Population

Lumbar zygapophysial (z-joint) pain is common. Medial branch blocks are the only validated test for the diagnosis of painful z-joints, and dual comparative medial branch blocks are currently recommended to accurately diagnosis painful z-joints and help reduce the false positive rate associated with interventional procedures. Intra-articular injection of corticosteroids is a common treatment suspected z-joint pain. No studies to date evaluate the efficacy of intra-articular corticosteroids in those with dual comparative medial branch block confirmed z-joint pain.

Radiographic Evidence of Lumbar Zygapophysial Joint Arthritis on MRI at Initial Zygapophysial Joint Injection or Medial Branch Block

PM&RVolume 5, Issue 9S p. S303-S303 Pain and Spine Medicine Radiographic Evidence of Lumbar Zygapophysial Joint Arthritis on MRI at Initial Zygapophysial Joint Injection or Medial Branch Block Jackson Cohen MD, Jackson Cohen MD University of Miami Miller School of Medicine, Miami, FL, United StatesSearch for more papers by this authorDaniel Rivera MD, Daniel Rivera MD University of Miami Miller School of Medicine, Miami, FL, United StatesSearch for more papers by this authorDouglas Johnson-Greene PHD, Douglas Johnson-Greene PHD University of Miami Miller School of Medicine, Miami, FL, United StatesSearch for more papers by this authorJose Mena MD, Jose Mena MD University of Miami Miller School of Medicine, Miami, FL, United StatesSearch for more papers by this authorAndrew L. Sherman MD, Andrew L. Sherman MD University of Miami Miller School of Medicine, Miami, FL, United StatesSearch for more papers by this author Jackson Cohen MD, Jackson Cohen MD University of Miami Miller School of Medicine, Miami, FL, United StatesSearch for more papers by this authorDaniel Rivera MD, Daniel Rivera MD University of Miami Miller School of Medicine, Miami, FL, United StatesSearch for more papers by this authorDouglas Johnson-Greene PHD, Douglas Johnson-Greene PHD University of Miami Miller School of Medicine, Miami, FL, United StatesSearch for more papers by this authorJose Mena MD, Jose Mena MD University of Miami Miller School of Medicine, Miami, FL, United StatesSearch for more papers by this authorAndrew L. Sherman MD, Andrew L. Sherman MD University of Miami Miller School of Medicine, Miami, FL, United StatesSearch for more papers by this author First published: 17 September 2013 https://doi.org/10.1016/j.pmrj.2013.08.552Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume5, Issue9SSeptember 2013Pages S303-S303 RelatedInformation

Assessment of the Escalating Growth of Facet Joint Interventions in the Medicare Population in the United States from 2000 to 2011

Background: Both the Office of Inspector General (OIG) and reports from studies of the utilization of facet joint interventions have expressed that explosive increases in facet joint interventions provided to spinal pain patients are a major concern. Study Design: The study is designed to assess the growth of facet joint interventions in managing spinal chronic pain in Medicare beneficiaries from 2000 to 2011. Objective: To assess the use of facet joint interventions in chronic pain management. Methods: The study was performed utilizing the Centers for Medicare and Medicaid Services (CMS) physician supplier procedure summary master data from 2000 to 2011. Results: The utilization of all types of facet joint interventions increased enormously from 2000 to 2011, with an overall increase of 308% per 100,000 Medicare beneficiaries and a 13.6% average annual increase. In addition, the highest increases were seen for cervical/ thoracic radiofrequency neurotomy with 836%, followed by an increase of 662% for lumbar/ sacral radiofrequency neurotomy, a 359% increase in cervical/thoracic facet joint injections, and 228% increase in lumbosacral facet joint injections. In reference to the number of procedures performed, however, the highest numbers were in the lumbosacral region with 990,449 total procedures of lumbar facet joint blocks and 406,378 lumbosacral radiofreqency neurotomies in 2011. Cervical and thoracic facet joint nerve blocks were 317,220, whereas cervical and thoracic radiofrequency neurotomies were 97,526 in 2011. The data also showed that there were enormous increases in the proportion of procedures performed by the specialty of physical medicine and rehabilitation, with an increase of 781% and an annual increase of 21.9% excluding physicians of physical medicine and rehabilitation enrolled as interventional pain management or pain management. Even though the numbers were very low for nurse anesthetists, nurse practitioners, and physician assistants, the increases were from 143 in 2000 to 21,263 in 2011, providing an annual increase of 55.2%, an overall increase of 12,460%. Limitations: The limitations of this study included a lack of inclusion of Medicare participants in Medicare Advantage plans, as well as potential documentation, coding, and billing errors. Furthermore, the data provided for state utilizations is based on claims data for that state which also may include patients from contiguous or other states receiving services in those states. Conclusions: The explosive increase in the number of lumbar facet joint interventions performed began to wane in 2008. From 2008 to 2010, the utilization of facet joint interventions declined by 6%. Key Words: Chronic spinal pain, interventional pain management, interventional techniques, facet joint injections, medial branch blocks, radiofrequency neurotomy

Correlation of Lumbar Medial Branch Neurotomy Results with Diagnostic Medial Branch Block Cut off Values: A Letter to the Editor

We read the article by Derby et al. with interest (Correlation of lumbar medial branch neurotomy results with diagnostic medial branch block cut off values to optimize therapeutic outcome: Pain Medicine 2012;13:1533–1546) ⇓. It is a well-conducted study that aims to establish a diagnostic test protocol to obtain a satisfactory result following medial branch neurotomy (MBN). A direct relationship between the diagnostic test protocol and the outcome of MBN can only be established once all the confounding factors affecting the outcome have been ruled out. However, in the present study, we could find few such factors described later. Whether the …

Response to Letter “Correlation of Lumbar Medial Branch Neurotomy Results with Diagnostic Medial Branch Block Cutoff Values to Optimize Therapeutic Outcome.” by Dr. Roy C. and Chatterjee N.: Table 1

Dear Editor, Thank you for taking the time for critically reviewing our article and allowing us an opportunity to further explain our results and to correct our omissions. Although we prospectively collected data, I again emphasize that the study is an audit of our usual and customary practices and techniques. The comparison in outcome between a single MBB protocol and a double MBB protocol is not a randomized comparison, but an opportunistic comparison based on insurance and patient preferences. In as much as our patient population is similar to other practices and in as much as the MBB and MBN techniques are similar or comparable, our audit could be used by others to provide their patients with an evidenced-based informed consent regarding the likelihood that they will be satisfied with the procedure and achieve a minimum of 50% subjective pain improvement for 6 months or longer based on a one- vs a two-MBB protocol. The likelihood degree is correlated to their perceived degree of improvement following a one- or two-session MBB protocol. Although we stated the senior author performed all the MBB thus implying he also performed the MBN, we should have specifically stated the following: The senior author with 30-year experience using MBB and MBN performed all the MBB and MBN procedures. The second author confirmed the prospectively collected audit by phone interview with the patients. The technique of performing MBB is a debatable topic that is beyond the scope of the article. The short …

Establishing an Optimal “Cutoff” Threshold for Diagnostic Lumbar Facet Blocks

Diagnostic medial branch blocks (MBB) are considered the reference standard for diagnosing facetogenic pain and selecting patients for radiofrequency (RF) denervation. Great controversy exists regarding the ideal cutoff for designating a block as positive. The purpose of this study is to determine the optimal pain relief threshold for selecting patients for RF denervation after diagnostic MBB. In this multicenter, prospective correlational study, 61 consecutive patients undergoing lumbar facet RF denervation after experiencing significant pain relief after MBB were enrolled. A positive outcome was defined as a ≥50% reduction in back pain at rest or with activity coupled with a positive satisfaction score lasting longer than 3 months. The relationship between pain relief after the blocks and denervation outcomes was evaluated by pairwise correlation matrix, receiver's operating characteristic curve, and stratifying outcomes based on 10- and 17-percentage point intervals for MBB. There were no significant differences in RF outcomes based on any MBB pain relief cutoff over 50%. A trend was noted whereby those patients who obtained <50% pain relief reported poorer outcomes. No optimal threshold for designating a diagnostic block as positive, above 50% pain relief, could be calculated. Employing more stringent selection criteria for lumbar facet RF is likely to result in withholding a beneficial procedure from a substantial number of patients, without improving success rates.

Lumbar Medial Branch Radiofrequency Neurotomy in New Zealand

This study aims to determine the effectiveness of lumbar medial branch radiofrequency neurotomy (RFN) performed by two practitioners trained according to rigorous guidelines. Prospective, outcome study of consecutive patients with chronic back pain treated in a community setting. A total of 106 patients, selected on the basis of complete relief of pain following controlled, diagnostic, medial branch blocks, were treated with RFN according to the guidelines of the International Spine Intervention Society. Successful outcome was defined as complete relief of pain for at least 6 months, with complete restoration of activities of daily living, no need for any further health care, and return to work. Patients who failed to meet any of these criteria were deemed to have failed treatment. In the two practices, 58% and 53% of patients achieved a successful outcome. Relief lasted 15 months from the first RFN and 13 months for repeat treatments. Allowing for repeat treatment, patients maintained relief for a median duration of 17-33 months, with some 70% still having relief at follow-up. Lumbar RFN can be very effective when performed in a rigorous manner in appropriately selected patients. Chronic back pain, mediated by the lumbar medial branches, can be stopped and patients fully restored to normal living, if treated with RFN.

An Update of Comprehensive Evidence-Based Guidelines for Interventional Techniques in Chronic Spinal Pain. Part II: Guidance and Recommendations

Objective: To develop evidence-based clinical practice guidelines for interventional techniques in the diagnosis and treatment of chronic spinal pain. Methodology: Systematic assessment of the literature. Evidence: I. Lumbar Spine • The evidence for accuracy of diagnostic selective nerve root blocks is limited; whereas for lumbar provocation discography, it is fair. • The evidence for diagnostic lumbar facet joint nerve blocks and diagnostic sacroiliac intraarticular injections is good with 75% to 100% pain relief as criterion standard with controlled local anesthetic or placebo blocks. • The evidence is good in managing disc herniation or radiculitis for caudal, interlaminar, and transforaminal epidural injections; fair for axial or discogenic pain without disc herniation, radiculitis or facet joint pain with caudal, and interlaminar epidural injections, and limited for transforaminal epidural injections; fair for spinal stenosis with caudal, interlaminar, and transforaminal epidural injections; and fair for post surgery syndrome with caudal epidural injections and limited with transforaminal epidural injections. • The evidence for therapeutic facet joint interventions is good for conventional radiofrequency, limited for pulsed radiofrequency, fair to good for lumbar facet joint nerve blocks, and limited for intraarticular injections. • For sacroiliac joint interventions, the evidence for cooled radiofrequency neurotomy is fair; limited for intraarticular injections and periarticular injections; and limited for both pulsed radiofrequency and conventional radiofrequency neurotomy. • For lumbar percutaneous adhesiolysis, the evidence is fair in managing chronic low back and lower extremity pain secondary to post surgery syndrome and spinal stenosis. • For intradiscal procedures, the evidence for intradiscal electrothermal therapy (IDET) and biaculoplasty is limited to fair and is limited for discTRODE. • For percutaneous disc decompression, the evidence is limited for automated percutaneous lumbar discectomy (APLD), percutaneous lumbar laser disc decompression, and Dekompressor; and limited to fair for nucleoplasty for which the Centers for Medicare and Medicaid Services (CMS) has issued a noncoverage decision. II. Cervical Spine • The evidence for cervical provocation discography is limited; whereas the evidence for diagnostic cervical facet joint nerve blocks is good with a criterion standard of 75% or greater relief with controlled diagnostic blocks. • The evidence is good for cervical interlaminar epidural injections for cervical disc herniation or radiculitis; fair for axial or discogenic pain, spinal stenosis, and post cervical surgery syndrome. • The evidence for therapeutic cervical facet joint interventions is fair for conventional cervical radiofrequency neurotomy and cervical medial branch blocks, and limited for cervical intraarticular injections. III. Thoracic Spine • The evidence is limited for thoracic provocation discography and is good for diagnostic accuracy of thoracic facet joint nerve blocks with a criterion standard of at least 75% pain relief with controlled diagnostic blocks. • The evidence is fair for thoracic epidural injections in managing thoracic pain. • The evidence for therapeutic thoracic facet joint nerve blocks is fair, limited for radiofrequency neurotomy, and not available for thoracic intraarticular injections. IV. Implantables • The evidence is fair for spinal cord stimulation (SCS) in managing patients with failed back surgery syndrome (FBSS) and limited for implantable intrathecal drug administration systems. V. Anticoagulation • There is good evidence for risk of thromboembolic phenomenon in patients with antithrombotic therapy if discontinued, spontaneous epidural hematomas with or without traumatic injury in patients with or without anticoagulant therapy to discontinue or normalize INR with warfarin therapy, and the lack of necessity of discontinuation of nonsteroidal anti-inflammatory drugs (NSAIDs), including low dose aspirin prior to performing interventional techniques. • There is fair evidence with excessive bleeding, including epidural hematoma formation with interventional techniques when antithrombotic therapy is continued, the risk of higher thromboembolic phenomenon than epidural hematomas with discontinuation of antiplatelet therapy prior to interventional techniques and to continue phosphodiesterase inhibitors (dipyridamole, cilostazol, and Aggrenox). • There is limited evidence to discontinue antiplatelet therapy with platelet aggregation inhibitors to avoid bleeding and epidural hematomas and/or to continue antiplatelet therapy (clopidogrel, ticlopidine, prasugrel) during interventional techniques to avoid cerebrovascular and cardiovascular thromboembolic fatalities. • There islimited evidence in reference to newer antithrombotic agents dabigatran (Pradaxa) and rivaroxan (Xarelto) to discontinue to avoid bleeding and epidural hematomas and are continued during interventional techniques to avoid cerebrovascular and cardiovascular thromboembolic events. Conclusion: Evidence is fair to good for 62% of diagnostic and 52% of therapeutic interventions assessed. Disclaimer: The authors are solely responsible for the content of this article. No statement on this article should be construed as an official position of ASIPP. The guidelines do not represent “standard of care.” Key words: Interventional techniques , chronic spinal pain, diagnostic blocks, therapeutic interventions, facet joint interventions, epidural injections, epidural adhesiolysis, discography, radiofrequency, disc decompression, spinal cord stimulation, intrathecal implantable systems

A Randomized Controlled Trial about the Levels of Radiation Exposure Depends on the Use of Collimation C-arm Fluoroscopic-guided Medial Branch Block

BackgroundC-arm fluoroscope has been widely used to promote more effective pain management; however, unwanted radiation exposure for operators is inevitable. We prospectively investigated the differences in radiation exposure related to collimation in Medial Branch Block (MBB).MethodsThis study was a randomized controlled trial of 62 MBBs at L3, 4 and 5. After the patient was laid in the prone position on the operating table, MBB was conducted and only AP projections of the fluoroscope were used. Based on a concealed random number table, MBB was performed with (collimation group) and without (control group) collimation. The data on the patient's age, height, gender, laterality (right/left), radiation absorbed dose (RAD), exposure time, distance from the center of the field to the operator, and effective dose (ED) at the side of the table and at the operator's chest were collected. The brightness of the fluoroscopic image was evaluated with histogram in Photoshop.ResultsThere were no significant differences in age, height, weight, male to female ratio, laterality, time, distance and brightness of fluoroscopic image. The area of the fluoroscopic image with collimation was 67% of the conventional image. The RAD (29.9 ± 13.0, P = 0.001) and the ED at the left chest of the operators (0.53 ± 0.71, P = 0.042) and beside the table (5.69 ± 4.6, P = 0.025) in collimation group were lower than that of the control group (44.6 ± 19.0, 0.97 ± 0.92, and 9.53 ± 8.16), resepectively.ConclusionsCollimation reduced radiation exposure and maintained the image quality. Therefore, the proper use of collimation will be beneficial to both patients and operators.