Comparative Local Anesthetic Blocks Research Articles

The Effectiveness of Medial Branch Blocks and Radiofrequency Neurotomy in Managing Chronic Thoracic Pain: A Systematic Review and Meta-Analysis

BACKGROUND: Extensive research into potential sources of thoracic pain with or without referred pain into the chest wall has demonstrated that thoracic facet joints can be a potential source of pain confirmed by precise, diagnostic blocks. The objective of this systematic review and meta-analysis is to evaluate the effectiveness of medial branch blocks and radiofrequency neurotomy as a therapeutic thoracic facet joint intervention. METHODS: Systematic review and meta-analysis of randomized controlled trials (RCTs) and observational studies of medial branch blocks and the radiofrequency neurotomy in managing thoracic pain utilizing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist was performed. A comprehensive literature search of multiple databases of RCTs and observational studies of medial branch blocks and radiofrequency neurotomy in managing chronic thoracic pain were identified from 1996 to December 2022 with inclusion of manual searches of the bibliography of known review articles and multiple databases. Methodologic quality and risk of bias assessment was also conducted. Evidence was synthesized utilizing principles of quality assessment and best evidence synthesis, with conventional and single meta-analysis. The primary outcome measure of success was 3 months of pain reduction for medial branch blocks and 6 months for radiofrequency thermoneurolysis for a single treatment. Short-term success was defined as up to 6 months and long-term was more than 6 months. RESULTS: This literature search yielded 11 studies meeting the inclusion criteria, of which 3 were RCTs and 8 were observational studies. Of the 3 RCTs, 2 of them assessed medial branch blocks and one trial assessed radiofrequency for thoracic pain. The evidence for managing thoracic pain with qualitative analysis and single-arm meta-analysis and GRADE system of appraisal, with the inclusion of 2 RCTs and 3 observational studies for medial branch blocks was Level II. For radiofrequency neurotomy, with the inclusion of one RCT of 20 patients in the treatment group and 5 observational studies, the evidence was Level III in managing thoracic pain. LIMITATIONS: There was a paucity of literature with RCTs and real-world pragmatic controlled trials. Even observational studies had small sample sizes providing inadequate clinically applicable results. In addition, there was heterogeneity of the available studies in terms of their inclusion and exclusion criteria, defining their endpoints and the effectiveness of the procedures. CONCLUSION: This systematic review and meta-analysis show Level II evidence of medial branch blocks and Level III evidence for radiofrequency neurotomy on a long-term basis in managing chronic thoracic pain. KEY WORDS: Chronic spinal pain, thoracic facet or zygapophysial joint pain, facet joint nerve blocks, medial branch blocks, controlled comparative local anesthetic blocks, diagnostic accuracy, radiofrequency neurotomy

Response to: Invasive Treatments for Low Back Disorders and the ACOEM Practice Guidelines.

Response to: Invasive Treatments for Low Back Disorders and the ACOEM Practice Guidelines.

Facet Joint Injections for the Management of Low Back Pain: A Clinical Review

Introduction: Lumbar facet joints have been implicated in chronic low back pain (LBP) in up to 45% of patients with LBP. Facet joint pain (FJP) diagnosis and management are always challenging for pain physicians. FJP is not diagnosed by specific demographic features, pain characteristics, or physical findings, despite the electrodiagnostic studies and imaging modalities being available. Although comparative local anesthetics or placebo saline injections can be used, diagnostic blocks are the only reliable diagnostic measures according to the current literature.
 Methodology: A randomized, controlled clinical trial was conducted to evaluate the effectiveness of lumbar facet joint injections. A total of 229 participants were enrolled to receive facet injections with bupivacaine and steroid, medial branch blocks, or saline.
 Result: The results of this study showed that facet joint injections had little long-term therapeutic utility, but had a prognostic value compared to control injections before radiofrequency ablation. Thus, the results of this study emphasized the diagnostic value of facet joint injections.
 Conclusion: FJP is not diagnosed by demographic features, pain characteristics, physical findings, electrodiagnostic studies, or radiological evaluation as other types of LBP. Diagnostic blocks using comparative local anesthetic blocks or placebo injections are the only reliable diagnostic measures according to the current literature. Their validity, specificity, and sensitivity are considered reliable in the diagnosis of FJP. Facet joint-related anatomical, clinical, and technical knowledge is essential for successful pain management. Pain physicians should embrace all aspects of FJP management, from diagnosis to interventional management.

Assessment of Prevalence of Cervical Facet Joint Pain with Diagnostic Cervical Medial Branch Blocks: Analysis Based on Chronic Pain Model

Research into cervical spinal pain syndromes has indicated that the cervical facet joints can be a potent source of neck pain, headache, and referred pain into the upper extremities. There have been multiple diagnostic accuracy studies, most commonly utilizing diagnostic facet joint nerve blocks and an acute pain model, as Bogduk has proposed. Subsequently, Manchikanti has focused on the importance of the chronic pain model and longer lasting relief with diagnostic blocks. To assess diagnostic accuracy of cervical facet joint nerve blocks with controlled comparative local anesthetic blocks, with updated assessment of prevalence, false-positive rate, and a description of philosophical paradigm shift from acute to chronic pain model, with concordant pain relief. This diagnostic accuracy study was performed with retrospective assessment of data to assess prevalence and false-positive rates. The study was performed in a non-university-based, multidisciplinary, interventional pain management, private practice in the United States. Cervical medial branch blocks were performed utilizing lidocaine 1% followed by bupivacaine 0.25% when appropriate response was obtained in an operating room under fluoroscopic guidance with 0.5 mL of lidocaine or bupivacaine from C3-C6 medial branches (levels blocked on joints involved). If a patient failed to respond to lidocaine with appropriate >= 80% pain relief, that patient was considered as negative for facet joint pain. If the response was positive with lidocaine block, a bupivacaine block was performed. The chronic cervical facet joint pain was diagnosed with cervical facet joint nerve blocks at a prevalence of 49.3% (95% CI, 43.6%, 55.0%) and with a false-positive rate of 25.6% (95% CI, 19.5%, 32.8%). This study also showed a single block prevalence rate of 66.3% (95% CI, 71.7%, 60.9%). Assessment of the duration of relief with each block showed greater than 80% for 6 days with lidocaine block and total relief of >= 50% of 31 days. In contrast, with bupivacaine, average duration of pain relief of >= 80% was 12 days with a total relief of >= 50% lasting for 55 days. Based on this investigation, utilizing a chronic pain model, there was significant difference in the relief patterns. This assessment showed prevalence and false-positive rates of 49.3% and 25.6% in chronic neck pain. Duration of relief >= 80% pain relief was 6 days with lidocaine and 12 days with bupivacaine, with total relief of >= 50% of 31 days with 55 days respectively.

Low Back Pain and Diagnostic Lumbar Facet Joint Nerve Blocks: Assessment of Prevalence, FalsePositive Rates, and a Philosophical Paradigm Shift from an Acute to a Chronic Pain Model

Background: Lumbar facet joints are a clinically important source of chronic low back pain. There have been extensive diagnostic accuracy studies, along with studies of influence on the diagnostic process, but most of them have utilized the acute pain model. One group of investigators have emphasized the importance of the chronic pain model and longer lasting relief with diagnostic blocks. Objective: To assess the diagnostic accuracy of lumbar facet joint nerve blocks with controlled comparative local anesthetic blocks and concordant pain relief with an updated assessment of the prevalence, false-positive rates, and a description of a philosophical paradigm shift from an acute to a chronic pain model. Study Design: Retrospective study to determine diagnostic accuracy, prevalence and falsepositive rates. Setting: A multidisciplinary, non-university based interventional pain management practice in the United States. Methods: Controlled comparative local anesthetic blocks were performed initially with 1% lidocaine, followed by 0.25% bupivacaine if appropriate response was obtained, in an operating room under fluoroscopic guidance utilizing 0.5 mL of lidocaine or bupivacaine at L3, L4 medial branches and L5 dorsal ramus. All patients non-responsive to lidocaine blocks were considered to be negative for facet joint pain. All patients were assessed after the diagnostic blocks were performed with ≥ 80% pain relief for their ability to perform previously painful movements. Results: The prevalence of lumbar facet joint pain in chronic low back pain was 34.1% (95% CI, 28.8%, 39.8%), with a false-positive rate of 49.8% (95% CI, 42.7%, 56.8%). This study also showed a single block prevalence rate of 67.9% (95% CI, 62.9%, 73.2%). Average duration of pain relief ≥ 80% was 6 days with lidocaine block and total relief of ≥ 50% of 32 days. With bupivacaine, the average duration of pain relief ≥ 80% was 13 days with total relief of ≥ 50% lasting for 55 days. Conclusion: This study demonstrated that the chronic pain model is more accurate and reliable with concordant pain relief. This updated assessment also showed prevalence and false-positive rates of 34.1% and 49.8%. Key words: Chronic spinal pain, lumbar facet or zygapophysial joint pain, facet joint nerve blocks, medial branch blocks, controlled comparative local anesthetic blocks, diagnostic accuracy, prevalence, false-positive rate

Influence of prior opioid exposure on diagnostic facet joint nerve blocks

To determine the influence of prior opioid use on the diagnostic validity of controlled comparative local anesthetic blocks in the diagnosis of facet joint involvement in chronic spinal pain. Data were evaluated from 438 patients with chronic spinal pain who underwent diagnostic facet joint nerve blocks. Patient data were divided into four groups based on the level of opioid use: group I (no opioid use), group II (low opioid use), group III (moderate opioid use), and group IV (high opioid use). Facet joint involvement was diagnosed utilizing controlled comparative local anesthetic blocks with 1 percent preservative-free lidocaine and 0.25 percent preservative-free bupivacaine. Prior and current opioid use did not show relationship to the diagnostic validity of controlled comparative local anesthetic blocks. Among patients not using opioids (group I), the prevalence of facet joint pain was shown to be 33 percent in the cervical spine, 40 percent in the thoracic spine, and 18 percent in the lumbar spine, with false-positive results with a single lidocaine block of 53 percent, 33 percent, and 54 percent, respectively. Facet joint involvement in patients with opioid use ranged from 37 percent to 53 percent in the cervical spine, 13 percent to 67 percent in the thoracic spine, and 28 percent to 33 percent in the lumbar spine. Overall, this evaluation demonstrated that current or prior opioid use is not associated with interference of the validity of controlled comparative local anesthetic blocks in diagnosing spinal facet joint-related pain.

Mathematical Validation and Credibility of Diagnostic Blocks for Spinal Pain

Diagnostic blocks are used in different ways for the diagnosis of spinal pain, but their validity has not been fully evaluated. Four clinical protocols were analyzed mathematically to determine the probability of correct responses arising by chance. The complement of this probability was adopted as a measure of the credibility of correct responses. The credibility of responses varied from 50% to 95%, and was determined less by the agents used but more by what information was given to patients and if the agents were fully randomized for each block. Randomized, comparative local anesthetic blocks offer a credibility of 75%, but randomized, placebo-controlled blocks provide a credibility of 95%, and are thereby suitable as a criterion standard for diagnostic blocks.

Management of lumbar zygapophysial (facet) joint pain.

To investigate the diagnostic validity and therapeutic value of lumbar facet joint interventions in managing chronic low back pain. The review process applied systematic evidence-based assessment methodology of controlled trials of diagnostic validity and randomized controlled trials of therapeutic efficacy. Inclusion criteria encompassed all facet joint interventions performed in a controlled fashion. The pain relief of greater than 50% was the outcome measure for diagnostic accuracy assessment of the controlled studies with ability to perform previously painful movements, whereas, for randomized controlled therapeutic efficacy studies, the primary outcome was significant pain relief and the secondary outcome was a positive change in functional status. For the inclusion of the diagnostic controlled studies, all studies must have utilized either placebo controlled facet joint blocks or comparative local anesthetic blocks. In assessing therapeutic interventions, short-term and long-term reliefs were defined as either up to 6 mo or greater than 6 mo of relief. The literature search was extensive utilizing various types of electronic search media including PubMed from 1966 onwards, Cochrane library, National Guideline Clearinghouse, clinicaltrials.gov, along with other sources including previous systematic reviews, non-indexed journals, and abstracts until March 2015. Each manuscript included in the assessment was assessed for methodologic quality or risk of bias assessment utilizing the Quality Appraisal of Reliability Studies checklist for diagnostic interventions, and Cochrane review criteria and the Interventional Pain Management Techniques - Quality Appraisal of Reliability and Risk of Bias Assessment tool for therapeutic interventions. Evidence based on the review of the systematic assessment of controlled studies was graded utilizing a modified schema of qualitative evidence with best evidence synthesis, variable from level I to level V. Across all databases, 16 high quality diagnostic accuracy studies were identified. In addition, multiple studies assessed the influence of multiple factors on diagnostic validity. In contrast to diagnostic validity studies, therapeutic efficacy trials were limited to a total of 14 randomized controlled trials, assessing the efficacy of intraarticular injections, facet or zygapophysial joint nerve blocks, and radiofrequency neurotomy of the innervation of the facet joints. The evidence for the diagnostic validity of lumbar facet joint nerve blocks with at least 75% pain relief with ability to perform previously painful movements was level I, based on a range of level I to V derived from a best evidence synthesis. For therapeutic interventions, the evidence was variable from level II to III, with level II evidence for lumbar facet joint nerve blocks and radiofrequency neurotomy for long-term improvement (greater than 6 mo), and level III evidence for lumbosacral zygapophysial joint injections for short-term improvement only. This review provides significant evidence for the diagnostic validity of facet joint nerve blocks, and moderate evidence for therapeutic radiofrequency neurotomy and therapeutic facet joint nerve blocks in managing chronic low back pain.

A Best-Evidence Systematic Appraisal of the Diagnostic Accuracy and Utility of Facet (Zygapophysial) Joint Injections in Chronic Spinal Pain

Background: Spinal zygapophysial, or facet, joints are a source of axial spinal pain and referred pain in the extremities. Conventional clinical features and other noninvasive diagnostic modalities are unreliable in diagnosing zygapophysial joint pain. Study Design: A systematic review of the diagnostic accuracy of spinal facet joint nerve blocks. Objective: To determine the diagnostic accuracy of spinal facet joint nerve blocks in chronic spinal pain. Methods: A methodological quality assessment of included studies was performed using Quality Appraisal of Reliability Studies (QAREL). Only diagnostic accuracy studies meeting at least 50% of the designated inclusion criteria were utilized for analysis. The level of evidence was classified as Level I to V based on the grading of evidence utilizing best evidence synthesis. Data sources included relevant literature identified through searches of PubMed and other electronic searches published from 1966 through March 2015, Cochrane reviews, and manual searches of the bibliographies of known primary and review articles. Outcome Measures: Studies must have been performed utilizing controlled local anesthetic blocks. The criterion standard must have been at least 50% pain relief from baseline scores and the ability to perform previously painful movements. Results: The available evidence is Level I for lumbar facet joint nerve blocks with the inclusion of a total of 17 studies with dual diagnostic blocks, with at least 75% pain relief with an average prevalence of 16% to 41% and false-positive rates of 25% to 44%. The evidence for diagnosis of cervical facet joint pain with cervical facet joint nerve blocks is Level II based on a total of 11 controlled diagnostic accuracy studies, with significant variability among the prevalence in a heterogenous population with internal inconsistency. The prevalence rates ranged from 36% to 67% with at least 80% pain relief as the criterion standard and a false-positive rate of 27% to 63%. The level of evidence for the diagnostic accuracy of thoracic facet joint nerve blocks is Level II with 80% or higher pain relief as the criterion standard with a prevalence ranging from 34% to 48% and false-positive rates ranging from 42% to 48%. Limitations: The shortcomings of this systematic review include a paucity of literature related to the thoracic spine, continued debate on an appropriate gold standard, appropriateness of diagnostic blocks, and utility. Conclusion: The evidence is Level I for the diagnostic accuracy of lumbar facet joint nerve blocks, Level II for cervical facet joint nerve blocks, and Level II for thoracic facet joint nerve blocks in assessment of chronic spinal pain. Key words: Chronic spinal pain, lumbar facet or zygapophysial joint pain, cervical facet or zygapophysial joint pain, thoracic facet or zygapophysial joint pain, facet joint nerve blocks, medial branch blocks, controlled comparative local anesthetic blocks

A Randomized, Double-Blind, Active-Controlled Trial of Fluoroscopic Lumbar Interlaminar Epidural Injections in Chronic Axial or Discogenic Low Back Pain: Results of 2-Year Follow-Up

Background: Chronic low back with or without lower extremity pain is extremely common, expensive, and disabling. Although it is responsible for a very small proportion of patients, disc herniation is the primary focus of modalities of treatments. In fact, chronic low back pain without disc herniation is common. Multiple modalities of treatments are utilized in managing axial or discogenic pain without disc herniation including surgery, intradiscal therapies, and epidural injections. There is, however, continued debate on the effectiveness, indications, and medical necessity of all modalities of treatments in managing axial or discogenic pain in the lumbar spine. Objectives: To assess the effectiveness of lumbar interlaminar epidural injections in managing chronic axial or discogenic low back pain with epidural injections of local anesthetic with or without steroids. Study Design: A randomized, double-blind, active-controlled trial. Setting: A private practice, specialty referral, interventional pain management practice in the United States. Methods: In this study, a total of 120 patients were randomly allocated to one of 2 groups of 60 patients receiving either local anesthetic alone or local anesthetic with steroids. The primary outcome measure was at least a 50% improvement in the numeric rating scale (NRS) and Oswestry Disability Index (ODI). Outcomes were assessed at 3, 6, 12, 18, and 24 months post treatment. Results: Significant pain relief and functional status improvement, defined as a reduction in scores from baseline of at least 50% or more, were observed in 72% of patients receiving local anesthetic alone and 67% of patients receiving local anesthetic with steroids. Opioid intake was reduced from the baseline in each group for 2 years. Limitations: The results of the study are limited by the lack of a placebo group. Conclusion: Lumbar interlaminar epidural injections of local anesthetic with or without steroids are effective in patients with chronic axial low back pain of discogenic origin without facet joint pain, disc herniation, and/or radiculitis. Key words: Lumbar disc herniation, axial or discogenic pain, lumbar interlaminar epidural injections, local anesthetic, steroids, controlled comparative local anesthetic blocks

An Update of the Systematic Assessment of the Diagnostic Accuracy of Lumbar Facet Joint Nerve Blocks

Background: Lumbar facet joints are a well recognized source of low back pain and referred pain in the lower extremity in patients with chronic low back pain. Conventional clinical features and other non-invasive diagnostic modalities are unreliable in diagnosing lumbar zygapophysial joint pain. Controlled diagnostic studies with at least 80% pain relief as the criterion standard have shown the prevalence of lumbar facet joint pain to be 16% to 41% of patients with chronic low back pain without disc displacement or radiculitis, with a false-positive rate of 17% to 49% with a single diagnostic block. Study Design: A systematic review of the diagnostic accuracy of lumbar facet joint nerve blocks. Objective: To determine and update the diagnostic accuracy of lumbar facet joint nerve blocks in the assessment of chronic low back pain. Methods: A methodological quality assessment of included studies was performed using Quality Appraisal of Reliability Studies (QAREL). Only diagnostic accuracy studies meeting at least 50% of the designated inclusion criteria were utilized for analysis. Studies scoring less than 50% are presented descriptively and analyzed critically. The level of evidence was classified as good, fair, and limited or poor based on the quality of evidence developed by the United States Preventive Services Task Force (USPSTF). Data sources included relevant literature identified through searches of PubMed and EMBASE from 1966 to June 2012, and manual searches of the bibliographies of known primary and review articles. Outcome Measures: Studies must have been performed utilizing controlled local anesthetic blocks. Pain relief was categorized as at least 50% pain relief from baseline pain and the ability to perform previously painful movements. Results: A total of 25 diagnostic accuracy studies were included. Of these, one study evaluated 50% to 74% relief as criterion standard with a single block with prevalence of 48%, 4 studies evaluated 75% to 100% relief as the criterion standard with a single block with a prevalence of 31% to 61%, 5 studies evaluated 50% to 74% relief as the criterion standard with controlled blocks with a prevalence of 15% to 61%, and 13 studies evaluated 75% to 100% relief as the criterion standard with controlled blocks with a prevalence of 25% to 45% in heterogenous populations. False-positive rates ranged from 17% to 66% in the 50% to 74% pain relief group and 27% to 49% with at least 75% relief as the criterion standard. Based on this evaluation, the evidence showed that there is good evidence for diagnostic facet joint nerve blocks with 75% to 100% pain relief as the criterion standard with dual blocks and fair evidence with 50% to 74% pain relief as the criterion standard with controlled diagnostic blocks; however, the evidence is poor with single diagnostic blocks of 50% to 74%, and limited for 75% or more pain relief as the criterion standard. Limitations: The shortcomings of this systematic review of the accuracy of diagnostic lumbar facet joint nerve blocks include a paucity of literature and continued debate on an appropriate gold standard. Conclusion: There is good evidence for diagnostic facet joint nerve blocks with 75% to 100% pain relief as the criterion standard with dual blocks, with fair evidence with 50% to 74% pain relief. Key words: Chronic low back pain, lumbar facet or zygapophysial joint pain, facet joint nerve blocks, medial branch blocks, controlled comparative local anesthetic blocks

An Updated Review of the Diagnostic Utility of Cervical Facet Joint Injections

Background: Chronic persistent neck pain with or without upper extremity pain is common in the general adult population with a prevalence of 48% for women and 38% for men, with persistent complaints in 22% of women and 16% of men. Multiple modalities of treatment are exploding in managing chronic neck pain along with increasing prevalence. However, there is a paucity of evidence for all modalities of treatments in managing chronic neck pain. Controlled studies have supported the existence of cervical facet or zygapophysial joint pain in 36% to 60% in heterogenous population of these patients. However, these studies also have shown false-positive results in 27% to 63% of patients with a single diagnostic block. Study Design: A systematic review of diagnostic cervical facet joint nerve blocks. Objective: To evaluate and update the accuracy of diagnostic facet joint nerve blocks in the diagnosis of facet joint pain. Methods: A methodological quality assessment of included studies was performed using Quality Appraisal of Reliability Studies (QAREL). Only diagnostic accuracy studies meeting at least 50% of the designated inclusion criteria were utilized for analysis. Studies scoring less than 50% are presented descriptively and critically analyzed. The level of evidence was classified as good, fair, and limited or poor based on the quality of evidence developed by the United States Preventive Services Task Force (USPSTF). Data sources included relevant literature identified through searches of PubMed and EMBASE from 1966 to June 2012, and manual searches of the bibliographies of known primary and review articles. Results: Overall, a total of 26 manuscripts were considered for diagnostic accuracy evaluation and 9 manuscripts for studies evaluating various factors influencing the diagnostic validity of facet joint interventions. Based on 9 studies meeting the inclusion criteria utilizing 75% to 100% pain relief as the criterion standard with controlled blocks, the evidence is good for diagnostic accuracy of cervical facet joint pain, with a prevalence of 36% to 60% with a false-positive rate of 27% to 63% with a single block. Based on 2 studies from the same group of authors, the evidence for 75% to 100% pain relief as the criterion standard with a single block is limited. The evidence is limited for a single diagnostic block with 50% to 74% pain relief as the criterion standard, whereas no studies were available assessing the accuracy of 50% to 74% pain relief as the criterion standard with controlled blocks. Limitations: The limitations of this systematic review include a paucity of literature on outcomes, randomized, placebo-controlled trials and a lack of consensus on a gold standard. Conclusions: Diagnostic cervical facet joint nerve blocks are safe, valid, and reliable. The strength of evidence for diagnostic facet joint nerve blocks is good with the utilization of controlled diagnostic blocks with at least 75% pain relief as the criterion standard; however, the evidence is limited for single blocks or dual blocks for relief of 50% to 74% and single blocks with at least 75% pain relief. Key words: Chronic neck pain, cervical facet or zygapophysial joint pain, cervical medial branch blocks, controlled comparative local anesthetic blocks

Fluoroscopic lumbar interlaminar epidural injections in managing chronic lumbar axial or discogenic pain

Among the multiple causes of chronic low back pain, axial and discogenic pain are common. Various modalities of treatments are utilized in managing discogenic and axial low back pain including epidural injections. However, there is a paucity of evidence regarding the effectiveness, indications, and medical necessity of any treatment modality utilized for managing axial or discogenic pain, including epidural injections. In an interventional pain management practice in the US, a randomized, double-blind, active control trial was conducted. The objective was to assess the effectiveness of lumbar interlaminar epidural injections of local anesthetic with or without steroids for managing chronic low back pain of discogenic origin. However, disc herniation, radiculitis, facet joint pain, or sacroiliac joint pain were excluded. Two groups of patients were studied, with 60 patients in each group receiving either local anesthetic only or local anesthetic mixed with non-particulate betamethasone. Primary outcome measures included the pain relief-assessed by numeric rating scale of pain and functional status assessed by the, Oswestry Disability Index, Secondary outcome measurements included employment status, and opioid intake. Significant improvement or success was defined as at least a 50% decrease in pain and disability. Significant improvement was seen in 77% of the patients in Group I and 67% of the patients in Group II. In the successful groups (those with at least 3 weeks of relief with the first two procedures), the improvement was 84% in Group I and 71% in Group II. For those with chronic function-limiting low back pain refractory to conservative management, it is concluded that lumbar interlaminar epidural injections of local anesthetic with or without steroids may be an effective modality for managing chronic axial or discogenic pain. This treatment appears to be effective for those who have had facet joints as well as sacroiliac joints eliminated as the pain source.

Is It Useful to Repeat Sacroiliac Joint Provocative Tests Post-Block?

To evaluate the diagnostic usefulness of repeating sacroiliac joint (SIJ) provocative tests post-block. Thirty-four patients with suspected unilateral mechanical SIJ pain participated. Eleven had confirmed SIJ origin pain (>79% pain relief with fluoroscopically guided comparative local anesthetic intra-articular blocks), whereas 23 were confirmed not to have SIJ origin pain (<80% pain relief with a single local anesthetic intra-articular block). Six SIJ provocative tests were performed 30 minutes prior to and following the blocks. Sensitivity, specificity, and likelihood ratios were calculated for subjects who had three or more positive pre-block SIJ provocative tests and for subjects in whom the majority of the SIJ provocative tests converted from positive to negative (normalized) post-block. The sensitivity, specificity, and likelihood ratios for subjects with three or more positive pre-block SIJ provocative tests were 0.82, 0.57, and 1.9, respectively (P=0.04). For subjects in whom the majority of the SIJ provocative tests normalized, the sensitivity was 0.89, specificity 0.30, and likelihood ratio 1.3 (P=0.3). Multiple positive pre-block SIJ provocative tests have diagnostic utility however post-block normalization of SIJ provocative tests does not.

Preliminary Results of a Randomized, DoubleBlind, Controlled Trial of Fluoroscopic Lumbar Interlaminar Epidural Injections in Managing Chronic Lumbar Discogenic Pain Without Disc Herniation or Radiculitis

Background: Low back pain without disc herniation is the most common problem among chronic pain disorders. Epidural injections are commonly used interventions in managing chronic low back pain without disc herniation. However, little evidence exists regarding the effectiveness, indications, and medical necessity of lumbar epidural injections in managing axial low back pain without disc herniation or radiculitis. Study Design: A randomized, double-blind, controlled trial. Setting: An interventional pain management practice, a specialty referral center, a private practice setting in the United States. Objectives: To evaluate the ability to provide effective and long-lasting pain relief with lumbar interlaminar epidural injections with local anesthetic with or without steroids in managing chronic low back pain not caused by disc herniation or radiculitis. Methods: Patients were randomly assigned to one of 2 groups with Group I patients receiving local anesthetic only, whereas Group II patients received local anesthetic mixed with non-particulate betamethasone. Seventy patients were included in this analysis. Randomization was performed by computer-generated random allocation sequence by simple randomization. Outcomes Assessment: Outcome measures included the Numeric Rating Scale (NRS), the Oswestry Disability Index 2.0 (ODI), employment status, and opioid intake. The assessments were done at baseline, 3 months, 6 months, and 12 months post-treatment. Significant pain relief and/or improvement in disability were defined as at least 50% improvement. Results: Significant pain relief (≥ 50%) was demonstrated in 74% of patients in Group I and 63% in Group II. Functional status improvement (reduction of ≥ 50%) in the ODI scores was seen in 71% of patients in Group I and 60% of patients in Group II. The overall average procedures per year were approximately 4. Limitations: The results of this study are limited by the lack of a placebo group and that it is a preliminary report of 35 patients in each group with a total of 70 patients. Conclusion: Lumbar interlaminar epidural injections of local anesthetic with or without steroids was effective in 63% and 74% of patients with chronic function-limiting low back pain without facet joint pain, disc herniation, and/or radiculitis. Key words: Chronic low back pain, lumbar interlaminar epidural injections, discogenic pain, disc herniation, radiculitis, local anesthetic, steroids, controlled comparative local anesthetic blocks

Making Sense of the Accuracy of Diagnostic Lumbar Facet Joint Nerve Blocks: An Assessment of the Implications of 50% Relief, 80% Relief, Single Block, or Controlled Diagnostic Blocks

Background: The presence of lumbar facet joint pain has been overwhelmingly supported and the accuracy of controlled diagnostic blocks has been demonstrated in multiple studies and confirmed in systematic reviews. However, controversy surrounds the following related issues: placebo control, the amount of relief (50% versus 80%), single block versus double block, and placebo or comparative control. Study Design: An observational report of an outcome study to establish the diagnostic accuracy of controlled lumbar facet joint nerve blocks. Setting: An interventional pain management practice setting in the United States. Objective: To determine the accuracy of controlled diagnostic blocks in managing lumbar facet joint pain at the end of 2 years, with 2 different criteria (50% or 80% relief) and single block versus double block. Methods: A previous study of 152 patients showed an 89.5% of sustained diagnosis of lumbar facet joint pain at the end of a 2-year follow-up period when the diagnosis was made with double blocks and at least 80% relief. The present evaluation includes comparison of the above results with a study of 110 patients undergoing lumbar facet joint nerve blocks with positive criteria of at least 50% relief and follow-up of 2 years. The inclusion criteria in both studies was based on a positive response to diagnostic controlled comparative local anesthetic lumbar facet joint blocks, with either 50% or 80% relief and the ability to perform previously painful movements. The treatment in both groups included therapeutic lumbar facet joint interventions either with facet joint nerve blocks or radiofrequency neurotomy. Outcome Measures: The sustained diagnosis of lumbar facet joint pain at the end of one year and 2 years based on pain relief and functional status improvement. Results: At the end of one year, the diagnosis was confirmed in 75% of the group with 50% relief, whereas it was 93% in the group with 80% relief. At the end of the 2-year follow-up, the diagnosis of lumbar facet joint pain was sustained in 51% of the patients in the group with 50% relief, whereas it was sustained in 89.5% of the patients with 80% relief. The results differed between 50% relief and 80% relief with prevalence of 61% facet joint pain with dual blocks with 50% relief, and 31% with dual blocks with 80% relief; whereas with only a single block, the prevalence was 73% with 50% relief and 53% in the 80% relief group. Limitations: The study is limited by its observational nature. Conclusion: Controlled diagnostic lumbar facet joint nerve blocks are valid utilizing the criteria of 80% pain relief and the ability to perform previously painful movements, with a sustained diagnosis of lumbar facet joint pain in at least 89.5% of the patients at the end of a 2-year follow-up. In contrast, the diagnosis was sustained in 51% of the patients with 50% relief at the end of 2 years. Thus, inappropriate diagnostic criteria will increase the prevalence of facet joint pain substantially, leading to inappropriate and unnecessary treatment. Key words: Chronic low back pain, lumbar facet or zygapophysial joint pain, facet joint nerve or medial branch blocks, controlled local anesthetic blocks, construct validity, diagnostic studies, diagnostic accuracy

Evaluation of Lumbar Facet Joint Nerve Blocks in Managing Chronic Low Back Pain: A Randomized, Double-Blind, Controlled Trial with a 2-Year Follow-Up

A randomized, double-blind, controlled trial. To determine the clinical effectiveness of therapeutic lumbar facet joint nerve blocks with or without steroids in managing chronic low back pain of facet joint origin. Lumbar facet joints have been shown as the source of chronic pain in 21% to 41% of low back patients with an average prevalence of 31% utilizing controlled comparative local anesthetic blocks. Intraarticular injections, medial branch blocks, and radiofrequency neurotomy of lumbar facet joint nerves have been described in the alleviation of chronic low back pain of facet joint origin. The study included 120 patients with 60 patients in each group with local anesthetic alone or local anesthetic and steroids. The inclusion criteria was based upon a positive response to diagnostic controlled, comparative local anesthetic lumbar facet joint blocks.Outcome measures included the numeric rating scale (NRS), Oswestry Disability Index (ODI), opioid intake, and work status, at baseline, 3, 6, 12, 18, and 24 months. Significant improvement with significant pain relief of >or= 50% and functional improvement of >or= 40% were observed in 85% in Group 1, and 90% in Group II, at 2-year follow-up.The patients in the study experienced significant pain relief for 82 to 84 weeks of 104 weeks, requiring approximately 5 to 6 treatments with an average relief of 19 weeks per episode of treatment. Therapeutic lumbar facet joint nerve blocks, with or without steroids, may provide a management option for chronic function-limiting low back pain of facet joint origin.

Accuracy of Diagnostic Lumbar Facet Joint Nerve Blocks: A 2-Year Follow-Up of 152 Patients Diagnosed with Controlled Diagnostic Blocks

Lumbar facet joint pain is diagnosed by controlled diagnostic blocks. The accuracy of controlled diagnostic blocks has been demonstrated in multiple studies and confirmed in systematic reviews. Controlled diagnostic studies have shown an overall prevalence of lumbar facet joint pain in 31% of the patients with chronic low back pain without disc displacement or radiculitis, with an overall false-positive rate of 30% using a single diagnostic block. An observational report of outcomes assessment. An interventional pain management practice setting in the United States. To determine the accuracy of controlled diagnostic blocks in managing lumbar facet joint pain at the end of 2 years. This study included 152 patients diagnosed with lumbar facet joint pain using controlled diagnostic blocks. The inclusion criteria was based on a positive response to diagnostic controlled comparative local anesthetic lumbar facet joint blocks. The treatment included therapeutic lumbar facet joint nerve blocks. The sustained diagnosis of lumbar facet joint pain at the end of one year and 2 years based on pain relief and functional status improvement. At the end of one year 93% of the patients and at the end of 2 years 89.5% of the patients were considered to have lumbar facet joint pain. The study is limited by its observational nature. Controlled diagnostic lumbar facet joint nerve blocks are valid utilizing the criteria of 80% pain relief and the ability to perform previously painful movements, with sustained diagnosis of lumbar facet joint pain in at least 89.5% of the patients at the end of a 2-year follow-up period.

Evaluation of Sacroiliac Joint Interventions: A Systematic Appraisal of the Literature

The sacroiliac joint has been implicated as a source of low back and lower extremity pain. There are no definite historical, physical, or radiological features that can definitively establish a diagnosis of sacroiliac joint pain. Based on the present knowledge, an accurate diagnosis is made only by controlled sacroiliac joint diagnostic blocks. The sacroiliac joint has been shown to be a source of pain in 10% to 27% of suspected patients with chronic low back pain utilizing controlled comparative local anesthetic blocks. A systematic review of diagnostic and therapeutic sacroiliac joint interventions. To evaluate the accuracy of diagnostic sacroiliac joint interventions and the utility of therapeutic sacroiliac joint interventions. The literature search was carried out by searching the databases of PubMed, EMBASE, and Cochrane reviews. Methodologic quality assessment of included studies was performed using the Agency for Healthcare Research and Quality (AHRQ) methodologic quality criteria for diagnostic accuracy and observational studies, whereas randomized trials were evaluated utilizing the Cochrane review criteria. Only studies with scores of 50 or higher were included for assessment. Level of evidence was based on the U.S. Preventive Services Task Force (USPSTF) criteria. For diagnostic interventions, the outcome criteria included at least 50% pain relief coupled with a patient's ability to perform previously painful maneuvers with sustained relief using placebo-controlled or comparative local anesthetic blocks. For therapeutic purposes, outcomes included significant pain relief and improvement in function and other parameters. Short-term relief for therapeutic interventions was defined as 6 months or less, whereas long-term effectiveness was defined as greater than 6 months. The indicated level of evidence is II-2 for the diagnosis of sacroiliac joint pain utilizing comparative, controlled local anesthetic blocks. The prevalence of sacroiliac joint pain is estimated to range between 10% and 38% using a double block paradigm in the study population. The false-positive rate of single, uncontrolled, sacroiliac joint injections is 20% to 54%. The evidence for provocative testing to diagnose sacroiliac joint pain is Level II-3 or limited. For radiofrequency neurotomy the indicated evidence is limited (Level II-3) for short- and long-term relief. The limitations of this systematic review include the paucity of literature evaluating the role of both diagnostic and therapeutic interventions and widespread methodological flaws. The indicated evidence for the validity of diagnostic sacroiliac joint injections is Level II-2. The evidence for the accuracy of provocative maneuvers in the diagnosing of sacroiliac joint pain is limited (Level II-3). The evidence for radiofrequency neurotomy is also limited (Level II-3).

Systematic Assessment of Diagnostic Accuracy and Therapeutic Utility of Lumbar Facet Joint Interventions

Lumbar facet joints are a well recognized source of low back pain and referred pain in the lower extremity in patients with chronic low back pain. Conventional clinical features and other non-invasive diagnostic modalities are unreliable in diagnosing lumbar zygapophysial joint pain. Controlled diagnostic studies have shown the prevalence of lumbar facet joint pain in 27% to 40% of the patients with chronic low back pain without disc displacement or radiculitis, with a false-positive rate of 27% to 47% with a single diagnostic block. A systematic review of diagnostic and therapeutic lumbar facet joint interventions. To determine the clinical utility of diagnostic and therapeutic lumbar facet joint interventions in managing chronic low back pain of facet joint origin. Review of the literature for clinical studies on efficacy and utility of facet joint interventions in diagnosing and managing facet joint pain was performed according to the Agency for Healthcare Research and Quality (AHRQ) criteria for diagnostic studies and observational studies and the Cochrane Musculoskeletal Review Group criteria as utilized for interventional techniques for randomized trials. Data sources included relevant literature of the English language identified through searches of Medline and EMBASE from 1966 to December 2008 and manual searches of bibliographies of known primary and review articles. Analysis results were performed for diagnostic and therapeutic interventions separately. The level of evidence was defined as Level I, II, or III with 3 subcategories in Level II based on the quality of evidence developed by the U.S. Preventive Services Task Force (USPSTF) for therapeutic interventions. For diagnostic interventions, studies must have been performed utilizing controlled local anesthetic blocks. Pain relief was categorized as at least 80% pain relief from baseline pain and ability to perform previously painful movements. For therapeutic interventions, the primary outcome measure was pain relief with secondary outcome measures of improvement in functional status, psychological status, return to work, and reduction in opioid intake. For therapeutic interventions, short-term pain relief was defined as relief lasting 6 months or less and long-term relief as longer than 6 months. Based on USPSTF criteria, evidence showed Level I or II-1 for diagnostic facet joint nerve blocks. Based on the review of included therapeutic studies, Level II-1 to II-2 evidence was indicated for lumbar facet joint nerve blocks with indicated level of evidence of Level II-2 to II-3 for lumbar radiofrequency neurotomy. The shortcoming of this systematic review of lumbar facet joint interventions is the paucity of published literature. The evidence for diagnosis of lumbar facet joint pain with controlled local anesthetic blocks is Level I or II-1. The indicated level of evidence for therapeutic lumbar facet joint interventions is Level II-1 or II-2 for lumbar facet joint nerve blocks, Level II-2 or II-3 evidence for radiofrequency neurotomy, and Level III (limited) evidence for intraarticular injections.