Medial Branch Nerve Blocks Research Articles

Clinical application of ultrasound in thoracic medial branch block and thoracic cooled-radiofrequency ablation: Case report and literature review

Introduction: Radiofrequency ablation is a procedure used to alleviate pain by destroying nerves with by radiofrequency-generated heat. Traditionally, radiofrequency ablation is preceded by diagnostic medial branch block injections, both guided by fluoroscopy. Fluoroscopic visualization of the superolateral aspect of the thoracic transverse process, where thoracic medial branch nerves occur, can be challenging due to anatomical complexities, especially in obese patients. We present a novel technique in which ultrasound was utilized in conjunction with fluoroscopy to perform medial branch block and radiofrequency ablation of the thoracic medial branch nerves. Case Report: First, two diagnostic thoracic medial branch nerve blocks were performed under ultrasound guidance. For the subsequent radiofrequency ablation, spinal needles were first advanced under ultrasound guidance to the target thoracic medial branch nerves. The position of those spinal needles was then used to guide the placement of cooled radiofrequency ablation probes using fluoroscopy. The patient reported 100% pain relief following the procedures. Discussion: We found that the addition of ultrasound allowed us to overcome the challenge of visualizing the superolateral aspect of thoracic transverse process under fluoroscopy alone. Direct ultrasound visualization allowed us to accurately and safely perform a thoracic medial branch block and radiofrequency ablation in a patient with poor fluoroscopic anatomy, as demonstrated by the patient’s complete pain relief after both medial branch block and radiofrequency ablation. We also theorize that our novel technique allows the provider to directly visualize the pleura, which could reduce the risk of severe pneumothorax associated with thoracic medial branch block and cooled radiofrequency ablation.

Mixed reality technology enhances teaching of spinal blockade procedures.

To investigate the efficacy of utilizing mixed reality technology-assisted teaching of a spinal medial branch nerve block. Twenty undergraduate students from a 5-year clinical medicine program in Fujian Medical University were selected. They were divided into group A and group B using a random number generator, with 10 students in each group. Group A used the traditional teaching method and Group B used the mixed reality technology-assisted teaching method. At the end of the teaching period, both groups were assessed on the blocking operation, number of punctures required, puncture time, and final error value (distance between the final position and the reference position). A questionnaire was administered to both groups to assess teaching satisfaction. The number of punctures required was 7.40 ± 1.26 and 2.10 ± 0.74 for groups A and B, respectively. The puncture time in group A was 297.80 ± 50.95 s and 65.60 ± 22.02 s in group B. All differences were significant p < 0.01. The final error of the puncture in group A was 2.24 ± 0.35 mm and 1.96 ± 0.26 mm in group B-not significant. Group B had (p < 0.01) higher evaluation scores than group A for teaching effectiveness, learning interest, initiative, and teaching satisfaction. The application of mixed reality technology in the teaching of posterior medial branch blocks of the spinal nerve is superior to previous methods. This method should be adopted wherever possible to enhance learning of this difficult technique.

The Acute VertEbRal AugmentaTion (AVERT) study: protocol for a randomised controlled, feasibility trial of spinal medial branch nerve block in hospitalised older patients with vertebral fragility fractures

IntroductionVertebral fragility fractures (VFFs) are the most common type of osteoporotic fracture found in older people, resulting in increasing morbidity and excess mortality. These fractures can cause significant pain, requiring...

Chronic Low Back Pain: The Therapeutic Benefits of Diagnostic Medial Branch Nerve Blocks

Chronic low back pain (CLBP) is an extremely prevalent disease, whose etiology is often multifactorial. Facet joint arthropathy is one of the most common causes of CLBP. Facet joints are innervated by the medial branches of the primary and adjacent level dorsal rami and are, therefore, key potential targets for the symptomatic management of CLBP. A lumbar medial branch nerve block (MBB) procedure is often used to assist in the diagnosis of facet mediated CLBP. For unclear reasons, some patients experience protracted relief of CLBP after diagnostic MBBs alone. To describe the phenomenon of protracted relief of CLBP after diagnostic MBBs and search for predictors of this response. A retrospective chart review of patients who underwent MBB procedures by a single practitioner, over a 2 year period, was conducted. All patients were seen at the Montefiore Multidisciplinary Pain Program, Bronx, NY. Data from follow up visits was used to categorize patient's response to MBBs as having no relief (NR), transient relief (TR) or protracted relief (PR). Patient demographics and characteristics were collected, and a multivariate analysis investigating associations with PR was conducted. 146 patients met inclusion criteria. 41 patients (28%) had NR, 54 (37%) had TR, and 51 (35%) had PR. CLBP symptom duration of < 6 months (P = 0.013) and unilateral back pain symptoms (P = 0.0253) were significantly associated with PR after MBB. This is a retrospective study with a relatively small sample size conducted on patients belonging to a single practitioner. Outcomes were based largely on subjective patient satisfaction scores. In select patients, MBB may produce protracted relief of CLBP symptoms. The authors present distinct hypotheses which may help explain the therapeutic effects of diagnostic MBB procedures.

Comparing the Efficacy of Combined Treatment with Medial Branch Block and Facet Joint Injection in Axial Low Back Pain.

Introduction Medial branch nerve block (MBB) and facet joint injections (FJIs) can be used to manage axial low back pain. Although there have been studies comparing the MBB and FJI effects, a few studies have compared the therapeutic effects of both interventions combined with each separate intervention. This study aimed to compare the pain relief effect of MBB, FJI, and combined treatment with MBB and FJI in patients with axial low back pain. Methods We conducted a retrospective review of patients with axial low back pain who had chart records of the Numeric Rating Scale (NRS) and Oswestry Disability Index (ODI) scores measured before treatment and within 6 weeks after treatment. The proportion of patients with successful responses (>30%) was calculated and is presented with Wald confidence intervals. Results We included 66 patients (33, 17, and 16 patients in the MBB, FJI, and combined treatment with MBB and FJI groups). All the patient groups showed significant posttreatment improvements in the NRS [(proportion >30% decrease: MBB 24.2% (9.6–38.9), FJI 29.4% (7.8–51.1), and MBB + FJI 25.0% (3.8–46.2)] scores and the ODI [proportion >30% decrease: MBB 39.4% (22.7–56.1), FJI 23.5% (3.4–43.7), and MBB + FJI 37.5% (13.8–61.2)] scores. Furthermore, there was no significant among-group difference in the ODI and NRS scores. Conclusion MBB, FJI, and combined treatment with MBB and FJI can reduce axial low back pain and improve secondary functional degradation. Although combined treatment with MBB and FJI required a longer intervention time, it did not have a pain relief effect superior to that of MBB or FJI alone.

Survey of Interventional Pain Physicians on Bending Spinal Needles for Chronic Pain Procedures

Background: Interventional pain procedures involve placement of fine-gauge spinal needles, which practitioners will frequently bend to facilitate both driving the needle through tissue, and to increase accuracy of placement at a specific spinal structure or nerve target. This bend is commonly performed by hand, leaving the proceduralist at risk for fingerstick injury, and the patient at risk of site contamination. However, few case studies have been published, and there are almost no data on physician preference or practice. Objectives: The purpose of this study was to survey interventional pain physicians on their practice of spinal needle manipulation before performing lumbar medial branch nerve blocks. Specific aims were to assess the prevalence of manual needle bending, and to determine possible associations with practitioner experience, clinical environment, and fingerstick injury. Study Design: A survey. Setting: Annual 2018 American Society for Interventional Pain Physicians conference in Orlando, Florida. Methods: A convenience sample of participants were screened for eligibility and asked to voluntarily participate in a de-identified IRB-approved survey (IRB201703055). The survey consisted of 5 questions, 2 with binary answer choices and the remaining 3 with multiple answer choices. Data were collected on an iPad via Qualtrics software. Data were analyzed by descriptive statistics (counts, percentages). Results: Of 480 interventional pain physician attendees at the conference, 154 (32.1%) completed the survey. The majority (114/154; 74%) reported ‘always’ bending the distal tip of spinal needles, and a further 21 (14%) reported ‘sometimes’; 19 (12%) said they do not bend their needles. Only 25 (18%) respondents used an instrument to bend their needles; 112 (82%) bend their needles by hand. Eight respondents (6%) reported a fingerstick injury while bending a spinal needle, one while using an instrument, and 7 during a manual bend. Approximately half of respondents had been practicing for greater than 15 years; 78% work in a private practice environment. Limitations: Due to the setting, the recruitment method presents the possibility of selection bias. Furthermore, although the response rate may appear low, it is higher than similarly performed studies. Conclusions: Spinal needle manipulation is common prior to performing interventional pain procedures, and most spinal needle manipulations are performed by hand. Rate of fingerstick injury was low in this sample, but cannot be evaluated without comparative data. Factors to be considered in a subsequent study are the effects of needle bend variability relative to practitioner experience and alternative means of needle manipulation. Key words: Interventional pain procedures, spinal needles, facet joint injections, needle bending, fingerstick injuries

Comparison of cervical medial branch nerve block versus trigger point injection in patients with chronic neck pain

Background: Annual prevalence of chronic neck pain in general population averages between 30%-50%. Among various causes of chronic neck pain cervical facet joint involvement accounts for about 54% to 67%. Interventional procedures such as medial branch nerve block, trigger point injections and dry needling have been described for management of chronic neck pain. Objectives: To determine the clinical effectiveness of cervical medial branch block and trigger point injections in the management chronic neck pain. Design: Randomized, double blinded, prospective study conducted at two different centers in India, Pain Clinic, Department of Anaesthesiology, J.N. Medical College hospital, Aligarh Muslim University, Aligarh, Delhi Pain management centre, New Delhi, India. Methods: Data analysis was done from a total of 60 patients with 30 patients in each group. Group CMB received cervical medial branch block and group TP received trigger point injection with levobupivacaine (0.25%) and triamcinolone (20mg) at two different levels. There was no sham group. Outcome Measure: Numeric rating scale (NRS), Neck Pain Disability Index (NDI), weekly analgesic requirement and subjective evaluation of patients was done at 1st week, 3rd week, 6th week and 12th week of follow up and compared with the pre-procedure value. Results: Significant pain relief was observed in both the groups of study, at 1st week of study, compared to baseline. Further follow up showed significantly better pain relief in patients receiving medial branch nerve block than patient receiving tender point injections at 3rd, 6th week and 12th week. NDI score in-group CMB was significantly better as compared to group TP at 3rd, 6th and 12th week follow up. Subjective evaluation of pain showed significantly greater proportion of patient with good to excellent pain relief in group receiving medial branch block. Analgesic requirement was significantly less in group CMB compared to group TP during follow up. Conclusion: Cervical medial branch block with local anaesthetic and steroid may provide long-term relief in patients with chronic neck pain than trigger point injection with no major incidence of complications in either group.

Observation of curative effect on lumbar facet joint syndrome by palace bonesetting therapeutic combined with lumbar medial branch nerve block

Objective To observe the clinical effect of palace bone-setting Dieda-Wanying cream combined with Yuan Shu Zhi Pai Zi fixation in the treatment of acute ankle sprain. Methods A total of 60 patients with acute ankle sprain were collected and randomly divided into observation group and control group according to the random number table method, with 30 cases in each group. The observation group was treated with Palace Bone-setting Dieda-Wanying cream combined with Yuan Shu Zhi Pai Zi for fixation. The control group was treated with external application of diclofenac diethylamine emulsion and fixation of elastic bandage. Two groups were treated for 14 days. The patients pain disappeared time and the swelling subsided, the VAS scale for assessment of ankle pain observed. The American Orthopedic Foot and Ankle Society (AOFAS) Ankle-after scoring system was used to assess the Ankle function, evaluation of clinical curative effect. Results The pain disappear time (9.7 ± 1.6 d vs. 13.4 ± 3.5 d, t=5.638), regression and time (3.5 ± 1.3 d vs. 6.7 ± 1.1 d, t=10.292) in the observation group were significantly earlier than those in the control group (P<0.01). After treatment, VAS score (1.9 ± 1.1 vs. 3.3 ± 1.3, t=4.503) of the observation group significantly lower than that of the control group (P<0.01); AOFAS score (93.6 ± 3.9 vs. 84.2 ± 5.1, t=8.019) significantly higher than the control group (P<0.01). Total effective rate in the observation group was 96.7% (29/30), and the control group was 80.0% (24/30), which the difference was statistically significant (χ2=4.043, P=0.044). Conclusions The Palace Bone-setting Dieda-Wanying cream combined with Yuan Shu Zhi Pai Zi fixation has definite curative effect on acute ankle sprain, relieve pain, swelling and promote the ankle function. Key words: Ankle joint; Sprains and strains; Dieda-Wanying cream; Yuan Shu Zhi Pai Zi; Palace bonesetting; Comparative effectiveness research

Facet-joint injections for non-specific low back pain: a feasibility RCT.

Pain of lumbar facet-joint origin is a common cause of low back pain in adults and may lead to chronic pain and disability, with associated health and socioeconomic implications. The socioeconomic burden includes an inability to return to work resulting in loss of productivity in addition to direct and indirect health-care utilisation costs. Lumbar facet-joints are paired synovial joints between the superior and inferior articular processes of consecutive lumbar vertebrae and between the fifth lumbar vertebra and the sacrum. Facet-joint pain is defined as pain that arises from any structure that is part of the facet-joints, including the fibrous capsule, synovial membrane, hyaline cartilage and bone. This pain may be treated by intra-articular injections with local anaesthetic and steroid, although this treatment is not standardised. At present, there is no definitive research to support the use of targeted lumbar facet-joint injections to manage this pain. Because of the lack of high-quality, robust clinical evidence, the National Institute for Health and Care Excellence (NICE) guidelines on the management of chronic low back pain [NICE. Low Back Pain in Adults: Early Management. Clinical guideline (CG88). London: NICE; 2009] did not recommend the use of spinal injections despite their perceived potential to reduce pain intensity and improve rehabilitation, with NICE calling for further research to be undertaken. The updated guidelines [NICE. Low Back Pain and Sciatica in Over 16s: Assessment and Management. NICE guideline (NG59). London: NICE; 2016] again do not recommend the use of spinal injections. To assess the feasibility of carrying out a definitive study to evaluate the clinical effectiveness and cost-effectiveness of lumbar facet-joint injections compared with a sham procedure in patients with non-specific low back pain of > 3 months' duration. Blinded parallel two-arm pilot randomised controlled trial. Initially planned as a multicentre study involving three NHS trusts in the UK, recruitment took place in the pain and spinal orthopaedic clinics at Barts Health NHS Trust only. Adult patients referred by their GP to the specialist clinics with non-specific low back pain of at least 3 months' duration despite NICE-recommended best non-invasive care (education and one of a physical exercise programme, acupuncture or manual therapy). Patients who had already received lumbar facet-joint injections or who had had previous back surgery were excluded. Participants who had a positive result following a diagnostic test (single medial branch nerve blocks) were randomised and blinded to receive either intra-articular lumbar facet-joint injections with steroids (intervention group) or a sham procedure (control group). All participants were invited to attend a group-based combined physical and psychological (CPP) programme. In addition to the primary outcome of feasibility, questionnaires were used to assess a range of pain-related (including the Brief Pain Inventory and Short-Form McGill Pain Questionnaire version 2) and disability-related (including the EuroQol-5 Dimensions five-level version and Oswestry Low Back Pain Questionnaire) issues. Health-care utilisation and cost data were also assessed. The questionnaire visits took place at baseline and at 6 weeks, 3 months and 6 months post randomisation. The outcome assessors were blinded to the allocation groups. Of 628 participants screened for eligibility, nine were randomised to receive the study intervention (intervention group, n = 5; sham group, n = 4), six completed the CPP programme and eight completed the study. Failure to achieve our expected recruitment targets led to early closure of the study by the funder. Because of the small number of participants recruited to the study, we were unable to draw any conclusions about the clinical effectiveness or cost-effectiveness of intra-articular lumbar facet-joint injections in the management of non-specific low back pain. Although we did not achieve the target recruitment rate from the pain clinics, we demonstrated our ability to develop a robust study protocol and deliver the intended interventions safely to all nine randomised participants, thus addressing many of the feasibility objectives. Stronger collaborations with primary care may improve the recruitment of patients earlier in their pain trajectory who are suitable for inclusion in a future trial. EudraCT 2014-003187-20 and Current Controlled Trials ISRCTN12191542. This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 74. See the NIHR Journals Library website for further project information.

Medial branch nerve block and ablation as a novel approach to pain related to vertebral compression fracture.

This review offers a critical examination of the biomechanical model that posits the posterior elements as a substantial contributor to pain in vertebral fracture. Further, the review assesses the treatment of posterior-element-associated pain in the setting of vertebral compression fracture in relation to vertebral augmentation. In 2015, the only prospective randomized trial comparing percutaneous vertebroplasty with facet blockade was published in which authors found that percutaneous vertebroplasty produced better pain relief and function based on Oswestry Disability Index, Roland Morris Disability Questionnaire, and visual analog scale in the short term (≤1 week). However, differences in pain relief at 1 month and 12 months were not statistically significant. The posterior elements may play a significant role in the pain generated after vertebral compression fractures. Treatment of the posterior element pain through medial branch radiofrequency ablation or facet injections may be another tool in providing analgesia in those with pain after vertebral compression fractures.

Ultrasound Guidance for Interventional Pain Management of Lumbar Facet Joint Pain: An Anatomical and Clinical Study

Background: There is a growing trend in ultrasound use in interventional pain management. Recently, the ease of use and clinical benefits of lumbar medial branch nerve block under ultrasound guidance have been identified. Objectives: In this study, we assessed the relevant anatomy and sonoanatomy of these specific interventional techniques. We also evaluated the feasibility and success rates of ultrasound guided lumbar medial branch nerve block. Patients and Methods: Thirty patients with facet joint pain who were referred to the Akhtar hospital pain clinics between 2011 and 2012 were evaluated. Eighty-nine ultrasound-guided lumbar medial branch nerve blocks were performed. The target point for the lumbar nerve block was the cephalad margin of the transverse process groove in the vicinity of the superior articular process. C-arm fluoroscopy was performed to confirm the needle location. Pain levels were measured by a visual analog scale (0 - 10 scale), the Oswestry disability index (0 - 5 scale), and patient satisfaction scores (0 - 3 scale). The patients were followed for 6 weeks. Results: The success rate was 98% (87/89 blocks), which was due to our use of ultrasound guided needle placement for the correct positioning of the needles. The mean procedural time was 5.9 ± 1 minutes. The average time of needle insertion was 4 ± 1 minutes. The pain intensity significantly improved from an initial value of 5 to 2.8 in the final follow-up (P = 0.0001). The oswestry disability index score significantly improved from 33.9 to 18.3 in the final follow-up (P = 0.0001). Patient satisfaction significantly improved from poor satisfaction immediately after the medial branch nerve block to excellent satisfaction in the final follow-up (P = 0. 0001). Analgesic requirements were also significantly reduced after 6 weeks of follow-up (P = 0.046). Conclusion: Lumbar medial branch nerve block under ultrasound guidance was associated with high rates of treatment success and excellent treatment outcomes for facet joint pain. It is also feasible and administers no radiation. Thus, ultrasound-guided procedures can be used instead of conventional methods.

Ultrasound-Guided Cervical Medial Branch Blocks: A Technical Review

Cervical medial branch blocks are commonly performed for the diagnosis and treatment of chronic neck pain and headaches. Although fluoroscopy constitutes the imaging standard for these procedures, recent evidence suggests that ultrasound guidance (USG) can provide similar accuracy coupled with shorter performance times. Moreover the ability to visualize soft tissue structures allows the operator to detect and avoid blood vessels, thus reducing complications related to vascular breach. In this review article, we discussed the technical considerations and evidence supporting the use of USG for cervical medial branch and third occipital nerve blocks.

Cervical spine pain related to the facet joints

Neck pain is a common diagnostic entity, with a lifetime prevalence of between 65% and 80%. Appreciation of the role of the cervical facet joints in the etiology of cervical spine pain is paramount to providing sustained pain relief for individuals suffering from degenerative and posttraumatic neck pain. Studies have demonstrated that approximately 60% of patients who sustain whiplash-type rear-end motor vehicle collisions would have pain that results from the facet joints alone, or in conjunction with the cervical intervertebral disks. An appreciation of the anatomical foundation for the development of these painful conditions includes knowledge of the dual, overlapping innervation of each cervical facet joint with contributions from levels at, and above the joint. Medial branch nerves invest the joints; are held closely adherent to the articular pillars by tendons of the semispinalis capitis muscles; and can be treated using local anesthetic nerve blocks followed by radiofrequency (RF) procedures for prolonged benefit. Nerves in facet joints contain modified nociceptors, including silent nociceptors, low-threshold mechanoreceptors, and mechanically sensitive nociceptors. Nerves within facet joints are both free and encapsulated and contain Substance P and calcitonin gene–related peptide. Treatment approaches must address these diverse anatomical and physiological phenomena to provide the highest level of interventional therapy. Large, well-conducted studies have demonstrated the efficacy and safety of providing short-term symptomatic pain relief using cervical facet medial branch nerve blocks. Continuous-energy thermal lesioning RF ablation techniques of the cervical medial branches may produce pain relief that persists for up to 12 months in two-thirds of patients so treated. A systematic review of well-conducted studies recently published confirmed that the evidence in favor of using RF ablation is level II for the long-term effectiveness of RF neurotomy and facet joint nerve blocks in managing cervical facet joint pain. Imaging for performing these procedures is mandatory to assure success and to minimize adverse events from occurring. Fluoroscopy is a standard imaging technique, but ultrasound and even computed tomography scan guidance have been documented to be satisfactory in properly trained interventionalists. The cervical facet joints with their medial branches represent a reliable target for directing interventional therapies aimed at addressing nociceptive type pain, albeit with a neurogenic component. Future studies would reflect our evolving appreciation of these intricate anatomical networks of innervation and their role in the etiology of chronic headache and neck pain.

Survey of sonoanatomic distances for lumbar medial branch nerve blocks in healthy volunteers.

BackgroundThe precise knowledge of anatomy and the region of transverse process (TP) and superior articular processes (AP) and their distance from the skin are important in blocking and treating lumbar facet syndrome. Evaluation of these anatomic distances from 3rd and 5th lumbar vertebrae in both sides and in different body mass index (BMI) in healthy volunteers might improve knowledge of ultrasound (US) lumbar medial branch nerve blocks (LMBB).MethodsBilateral US in the 3rd and 5th lumbar vertebrae of 64 volunteers carried out and the distance between skin to TP and skin to AP was measured. These distances were compared on both sides and in different BMI groups. The analysis was done using SPSS 11. Analysis of variance was used to compare the means at three vertebral levels (L3-L5) and different BMI groups. P values less than 0.05 were considered statistically significant. The paired t-test was used to compare the mean distance between skin to TP and skin to AP on both sides.ResultsThe distance between skin to TP and skin to AP of 3rd vertebrae to 5th vertebrae was increased in both right and left sides (P < 0.001) from up to down. The mean distance from skin to TP were greater on the left side compared to the right in all three vertebral levels from L3 to L5 (P values 0.014, 0.024, and 0.006 respectively). The mean distance from skin to TP and the skin to AP was statistically significant in different BMI groups (P < 0.001).ConclusionsWe found many anatomic distances which may increase awareness of US guided LMBB.

Effect of Facet Joint Injection Versus Systemic Steroids in Low Back Pain

Randomized clinical trial. To compare the effectiveness of facet joint injection versus systemic steroid in patients with a diagnosis of facet joint syndrome. The term facet joint syndrome has been used to define back pain originating from the facet joints. Treatment is mainly conservative, although interventions, including intra-articular injections and medial branch nerve blocks are used to manage facet-mediated pain. Several studies have evaluated the effectiveness of these interventions. Results of facet joint injection, however, are conflicting. Sixty subjects with a diagnosis of facet joint syndrome were enrolled in the study. They were randomized into experimental and control groups. The experimental group was administered with intra-articular injection of 6 lumbar facet joints with triamcinolone hexacetonide; the control group was administered with triamcinolone acetonide intramuscular injection of 6 lumbar paravertebral points. Visits were taken at baseline and at 1, 4, 12, and 24 weeks after interventions. Outcome measures were used: pain visual analogue scale, pain visual analogue scale during extension of the spine, Likert scale, improvement percentage scale, Roland-Morris, 36-Item Short Form Health Survey, and accountability of medications taken.Homogeneity was tested using the Student t, Pearson χ, and Mann-Whitney tests. Analysis of variance was used to analyze differences in the groups over time and the Student t test to analyze differences between groups at each time evaluation. The groups were similar at baseline. Comparisons between the groups showed, in analysis of variance analysis, an improvement in the experimental group regarding diclofenac intake and quality of life, in the "role physical" profile, assessed by 36-Item Short Form Health Survey.In the analysis at each time point, an improvement in the experimental group was also found in the Roland-Morris questionnaire, in the improvement percentage scale and in the response to treatment, assessed by the Likert scale. Both treatments were effective, with a slight superiority of the intra-articular injection of steroids over intramuscular injection.

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

AB1102 Effectiveness of facet joint injection in low back pain

BackgroundLumbar facet joints are a well recognized source of low back pain. Studies have shown the prevalence of lumbar facet joint pain in 30% to 40% of the patients with...

Duration of Fluoroscopic-Guided Spine Interventions and Radiation Exposure Is Increased in Overweight Patients

The impact of patient body mass index (BMI) on image-guided spine interventions remains unknown. Higher BMI is known to complicate the acquisition of radiographic images. Therefore it can be hypothesized that the patient's body habitus can influence the delivery of a spinal injection. To quantify the impact of patient BMI on the length of fluoroscopy and procedure times during spine interventions. Secondary analysis of 2 prospective observational studies. All injections were performed in an outpatient university setting. A total of 209 patients in whom spine injections were performed (99 women), with a mean age of 54.6 years. The fluoroscopy times for 202 participants and total procedure times for 137 participants were recorded. Additional participant characteristics, including age, gender, BMI, and actual procedures performed, also were collected. Analysis of covariance and linear and nonlinear model analysis were performed to assess the effect of BMI on fluoroscopy and procedure times. Fluoroscopy time and procedure duration times. Participants had a mean age of 54.6 years, 51% were men, and 77% (n = 155) were overweight (BMI ≥25). Participants received the following interventions: 40 zygapophyseal joint injections, 33 medial branch nerve blocks, 113 transforaminal epidural injections, and 16 combined zygapophyseal joint injections and epidural injections. Gender, procedure number, and procedure type did not differ between groups. The overweight group demonstrated a 30% increase in mean fluoroscopy time and a 35% increase in mean procedure time. Controlling for other variables, we found that differences in fluoroscopy time and procedure time were significant (P = .032 and P = .031, respectively) between the 2 groups. Significantly prolonged procedure time and fluoroscopy time in overweight patients increase the risks associated with spine interventions, not only to the patients but also to the operating room staff exposed to ionizing radiation.

Ultrasound versus Fluoroscopy in Image-guided Pain Treatment

Ultrasound <i>versus</i> Fluoroscopy in Image-guided Pain Treatment

Complications of Fluoroscopically Directed Facet Joint Nerve Blocks: A Prospective Evaluation of 7,500 Episodes with 43,000 Nerve Blocks

Background: Chronic spinal pain is common along with numerous modalities of diagnostic and therapeutic interventions utilized, creating a health care crisis. Facet joint injections and epidural injections are the 2 most commonly utilized interventions in managing chronic spinal pain. While the literature addressing the effectiveness of facet joint nerve blocks is variable and emerging, there is paucity of literature on adverse effects of facet joint nerve blocks. Study Design: A prospective, non-randomized study of patients undergoing interventional techniques from May 2008 to December 2009. Setting: A private interventional pain management practice, a specialty referral center in the United States. Objectives: Investigation of the incidence in characteristics of adverse effects and complications of facet joint nerve blocks. The study was carried out over a period of 20 months including almost 7,500 episodes of 43,000 facet joint nerve blocks with 3,370 episodes in the cervical region, 3,162 in the lumbar region, and 950 in the thoracic region. All facet joint nerve blocks were performed under fluoroscopic guidance in an ambulatory surgery center by 3 physicians. The complications encountered during the procedure and postoperatively were evaluated prospectively. Methods: This study was carried out over a period of 20 months and included over 7,500 episodes or 43,000 facet joint nerve blocks. All of the interventions were performed under fluoroscopic guidance in an ambulatory surgery center by one of 3 physicians. The complications encountered during the procedure and postoperatively were prospectively evaluated. Outcomes Assessment: Measurable outcomes employed were intravascular entry of the needle, profuse bleeding, local hematoma, dural puncture and headache, nerve root or spinal cord irritation with resultant injury, and infectious complications. Results: There were no major complications. Multiple side effects and complications observed included overall intravascular penetration in 11.4% of episodes with 20% in cervical region, 4% in lumbar region, and 6% in thoracic region; local bleeding in 76.3% of episodes with highest in thoracic region and lowest in cervical region; oozing with 19.6% encounters with highest in cervical region and lowest in lumbar region; with local hematoma seen only in 1.2% of the patients with profuse bleeding, bruising, soreness, nerve root irritation, and all other effects such as vasovagal reactions observed in 1% or less of the episodes. Limitations: Limitations of this study include lack of contrast injection, use of intermittent fluoroscopy and also an observational nature of the study. Conclusion: This study illustrate that major complications are extremely rare and minor side effects are common. Key words: Spinal pain, facet joint nerve blocks, cervical medial branch or facet joint nerve blocks, thoracic medial branch or facet joint nerve blocks, lumbar facet joint nerve blocks, L5 dorsal ramus block complications