Low back pain-related healthcare utilization following intraosseous basivertebral nerve radiofrequency ablation: a pooled analysis from three prospective clinical trials.

BACKGROUND: The effectiveness and safety of intraosseous basivertebral nerve ablation (BVNA) for treating vertebrogenic pain is established, but low back pain-related healthcare utilization (LBPr-HU) following BVNA continues to be defined. METHODS: LBPr-HU data were pooled from 3 prospective studies. LBPr-HU categories of interest included non-invasive conservative care, opioid utilization, lumbosacral spinal injection (LSI), lumbosacral radiofrequency ablation (LRFA), and lumbosacral spinal surgery. Pre- and post-BVNA LBPr-HU were compared at both 1- and 5-years using McNemar's test for proportions and paired t-tests for means. RESULTS: Two hundred forty-seven patients received BVNA and had 1-year follow-up; 205 had long-term follow-up (mean of 5.3 ± 1.33 years). Twenty-seven percent fewer participants initiated conservative care in the year post-BVNA compared to the year preceding BVNA (P < .001; 95% CI 19.8-34.5). Of 77/247 participants taking opioids at baseline, 40.3% and 61.7% fewer were taking them at one-year and 5.3 ± 1.33 years post-BVNA, respectively (P < .001). Of participants receiving LSIs in the year preceding BVNA, 81.2% fewer received LSI(s) in the year post-BVNA (P < .001; 95% CI 70.7-90.7); a 76.4% reduction in LSIs was maintained through a mean of 5.3 ± 1.33 years post-BVNA. LRFA rates were 1.6% at 1-year post-BVNA and 8.3% at 5.3 ± 1.33 years post-BVNA. Lumbar fusion surgery was 0.8% at 1-year post-BVNA and 6.5% at 5.3 ± 1.33 years post-BVNA. CONCLUSIONS: In this aggregate analysis of patients with vertebrogenic pain, utilization of conservative care, opioids, LSIs, and LRFA were substantially reduced through 5 years post-BVNA compared to baseline. Lumbar fusion rates were less than half the published value at 5 years in similar populations.

Biomechanical Phenotyping of Chronic Low Back Pain: Protocol for BACPAC.

OBJECTIVE: Biomechanics represents the common final output through which all biopsychosocial constructs of back pain must pass, making it a rich target for phenotyping. To exploit this feature, several sites within the NIH Back Pain Consortium (BACPAC) have developed biomechanics measurement and phenotyping tools. The overall aims of this article were to: 1) provide a narrative review of biomechanics as a phenotyping tool; 2) describe the diverse array of tools and outcome measures that exist within BACPAC; and 3) highlight how leveraging these technologies with the other data collected within BACPAC could elucidate the relationship between biomechanics and other metrics used to characterize low back pain (LBP). METHODS: The narrative review highlights how biomechanical outcomes can discriminate between those with and without LBP, as well as among levels of severity of LBP. It also addresses how biomechanical outcomes track with functional improvements in LBP. Additionally, we present the clinical use case for biomechanical outcome measures that can be met via emerging technologies. RESULTS: To answer the need for measuring biomechanical performance, our "Results" section describes the spectrum of technologies that have been developed and are being used within BACPAC. CONCLUSION AND FUTURE DIRECTIONS: The outcome measures collected by these technologies will be an integral part of longitudinal and cross-sectional studies conducted in BACPAC. Linking these measures with other biopsychosocial data collected within BACPAC increases our potential to use biomechanics as a tool for understanding the mechanisms of LBP, phenotyping unique LBP subgroups, and matching these individuals with an appropriate treatment paradigm.

Magnetic Resonance Imaging Characteristics Associated with Treatment Success from Basivertebral Nerve Ablation: An Aggregated Cohort Study of Multicenter Prospective Clinical Trials Data.

OBJECTIVE: Investigate associations between endplate and motion segment magnetic resonance imaging (MRI) characteristics and treatment outcomes following basivertebral nerve radiofrequency ablation (BVN RFA) in patients with clinically suspected vertebral endplate pain (VEP). DESIGN: Aggregated cohort study of 296 participants treated with BVN RFA from three prospective clinical trials. METHODS: Baseline MRI characteristics were analyzed using stepwise logistic regression to identify factors associated with treatment success. Predictive models used three definitions of treatment success: (1) ≥50% low back pain (LBP) visual analog scale (VAS), (2) ≥15-point Oswestry Disability Index (ODI), and (3) ≥50% VAS or ≥15-point ODI improvements at 3-months post-BVN RFA. RESULTS: The presence of lumbar facet joint fluid (odds ratio [OR] 0.586) reduced the odds of BVN RFA treatment success in individuals with clinically suspected VEP. In patients with a less advanced degenerative disc disease (DDD) profile, a > 50% area of the endplate with bone marrow intensity changes (BMIC) was predictive of treatment success (OR 4.689). Both regressions areas under the curve (AUCs) were under 70%, indicating low predictive value. All other vertebral endplate, intervertebral disc, nerve roots facet joint, spinal segmental alignment, neuroforamina, lateral recesses, and central canal MRI characteristics were not associated with BVN RFA success. CONCLUSIONS: In patients with vertebrogenic low back pain with Modic changes, the presence of degenerative findings of the anterior and posterior column was not associated with a clinically important impact on BVN RFA treatment success. None of the models demonstrated strong predictive value, indicating that the use of objective imaging biomarkers (Type 1 and/or 2 Modic changes) and a correlating presentation of pain remain the most useful patient selection factors for BVN RFA.

Gait Variability to Phenotype Common Orthopedic Gait Impairments Using Wearable Sensors.

Mobility impairments are a common symptom of age-related degenerative diseases. Gait features can discriminate those with mobility disorders from healthy individuals, yet phenotyping specific pathologies remains challenging. This study aims to identify if gait parameters derived from two foot-mounted inertial measurement units (IMU) during the 6 min walk test (6MWT) can phenotype mobility impairment from different pathologies (Lumbar spinal stenosis (LSS)-neurogenic diseases, and knee osteoarthritis (KOA)-structural joint disease). Bilateral foot-mounted IMU data during the 6MWT were collected from patients with LSS and KOA and matched healthy controls (N = 30, 10 for each group). Eleven gait parameters representing four domains (pace, rhythm, asymmetry, variability) were derived for each minute of the 6MWT. In the entire 6MWT, gait parameters in all four domains distinguished between controls and both disease groups; however, the disease groups demonstrated no statistical differences, with a trend toward higher stride length variability in the LSS group (p = 0.057). Additional minute-by-minute comparisons identified stride length variability as a statistically significant marker between disease groups during the middle portion of 6WMT (3rd min: p ≤ 0.05; 4th min: p = 0.06). These findings demonstrate that gait variability measures are a potential biomarker to phenotype mobility impairment from different pathologies. Increased gait variability indicates loss of gait rhythmicity, a common feature in neurologic impairment of locomotor control, thus reflecting the underlying mechanism for the gait impairment in LSS. Findings from this work also identify the middle portion of the 6MWT as a potential window to detect subtle gait differences between individuals with different origins of gait impairment.

Intraosseous Basivertebral Nerve Radiofrequency Ablation for the Treatment of Vertebral Body Endplate Low Back Pain: Current Evidence and Future Directions.

Recently, basivertebral nerve (BVN) radiofrequency ablation has been developed for the treatment of chronic low back pain (CLBP) thought to arise from the vertebral body endplates (VEPs). This review describes the relevant neuroanatomy and pathobiology of VEP degeneration and injury, imaging correlates of presumed VEP pain, randomized controlled trials performed, appropriate patient selection, and safety. Anatomic, histological, and clinical evidence supports the concept of the VEP as a source of CLBP and the nociceptive role of the BVN. BVN radiofrequency ablation appears to be an effective treatment for a subset of patients with CLBP and evidence of Modic change types 1 and 2 in the L3 to S1 VEPs who have failed to respond to conservative treatment. However, all studies performed to date have been industry sponsored, and future non-industry-funded trials will be needed to confirm these results.

Preoperative epidural steroid injections are not associated with increased rates of infection and dural tear in lumbar spine surgery.

PURPOSE: The study objectives were to use a large national claims data resource to examine rates of preoperative epidural steroid injections (ESI) in lumbar spine surgery and determine whether preoperative ESI or the timing of preoperative ESI is associated with rates of postoperative complications and reoperations. METHODS: A retrospective longitudinal analysis of patients undergoing lumbar spine surgery for disc herniation and/or spinal stenosis was undertaken using the MarketScan® databases from 2007-2015. Propensity-score matched cohorts were constructed to compare rates of complications and reoperations in patients with and without preoperative ESI. RESULTS: Within the year prior to surgery, 120,898 (46.4%) patients had a lumber ESI. The median time between ESI and surgery was 10 weeks. 23.1% of patients having preoperative ESI had more than one level injected, and 66.5% had more than one preoperative ESI treatment. Patients with chronic pain were considerably more likely to have an ESI prior to their surgery [OR 1.62 (1.54, 1.69), p < 0.001]. Patients having preoperative ESI within in close proximity to surgery did not have increased rates of infection, dural tear, neurological complications, or surgical complications; however, they did experience higher rates of reoperations and readmissions than those with no preoperative ESI (p < 0.001). CONCLUSION: Half of patients undergoing lumbar spine surgery for stenosis and/or herniation had a preoperative ESI. These were not associated with an increased risk for postoperative complications, even when the ESI was given in close proximity to surgery. Patients with preoperative ESI were more likely to have readmissions and reoperations following surgery.

Incidence of Extravascular Perivertebral Artery Contrast Flow During Cervical Transforaminal Epidural Injections.

BACKGROUND: During a cervical transforaminal epidural injection, injectate flows along the path of least resistance. Given the proximity of the vertebral artery to the intervertebral foramen, injected contrast may flow along the external wall of the artery. The incidence of this contrast flow pattern during cervical transforaminal epidural injections is unknown. PURPOSE: To determine the incidence of extravascular perivertebral artery contrast flow patterns during cervical transforaminal epidural injections. STUDY DESIGN/SETTING: Retrospective, observational, in vivo study. PATIENT SAMPLE: Patients receiving cervical transforaminal epidural injections at a single outpatient spine clinic. OUTCOME MEASURES: The presence or absence of extravascular perivertebral artery contrast flow. METHODS: The saved images from 100 consecutive patients were reviewed by two independent observers and classified with or without extravascular perivertebral artery contrast flow. The incidence was determined and kappa was used to examine inter-rater reliability. All disagreements were reviewed, and the final classification was determined by consensus. RESULTS: The inter-rater reliability was moderate, with a kappa value of 0.69. The incidence of extravascular perivertebral artery contrast flow patterns was 49% by consensus. No statistically significant differences in incidence were present when comparing three different final needle tip positions. CONCLUSIONS: During a cervical transforaminal epidural injection, an extravascular perivertebral artery contrast flow pattern is frequently encountered. This includes flow along the exiting nerve and then around the vertebral artery, as suggested by this study. Although this contrast pattern does not represent an intravascular injection into the vertebral artery, practitioners should remain cautious to exclude intravascular needle placement before injecting medication.

Smoking Is Associated with Pain in All Body Regions, with Greatest Influence on Spinal Pain.

OBJECTIVE: Examine the interrelationship between smoking and pain in the US population. DESIGN: A cross-sectional population-based study. SETTING: Nationwide survey. METHODS: Comprehensive pain reports categorically defined as head, spine, trunk, and limb pain; smoking history; demographics; medical history from a total of 2,307 subjects from the 2003-2004 National Health and Nutrition Examination Survey obtained from the Centers for Disease Control were analyzed. Unpaired t tests were used to analyze independent continuous variables, and chi-square tests were used to analyze categorical variables between smoker and nonsmoker groups. Weighted multivariate logistic regression analyses determined the association of current smoking with the presence of pain in various body regions. RESULTS: Smoking is most strongly associated with spine pain (odds ratio [OR] = 2.89, 95% confidence interval [CI] = 2.21-3.77), followed by headache (OR = 2.47, 95% CI = 1.73-3.53), trunk pain (OR = 2.17, 95% CI = 1.45-2.74), and limb pain (OR = 1.99, 95% CI = 1.45-2.73). CONCLUSIONS: Current smoking is associated with pain in every region of the body. This association is strongest for spine and head pain. Given that pain is a strong motivator and that current smoking was associated with pain in all body regions, we recommend that these results be used to further raise public awareness about the potential harms of smoking.

Digital Care for Chronic Musculoskeletal Pain: 10,000 Participant Longitudinal Cohort Study.

BACKGROUND: Chronic musculoskeletal pain has a vast global prevalence and economic burden. Conservative therapies are universally recommended but require patient engagement and self-management to be effective. OBJECTIVE: This study aimed to evaluate the efficacy of a 12-week digital care program (DCP) in a large population of patients with chronic knee and back pain. METHODS: A longitudinal observational study was conducted using a remote DCP available through a mobile app. Subjects participated in a 12-week multimodal DCP incorporating education, sensor-guided exercise therapy (ET), and behavioral health support with 1-on-1 remote health coaching. The primary outcome was pain measured by the visual analog scale (VAS). Secondary measures included engagement levels, program completion, program satisfaction, condition-specific pain measures, depression, anxiety, and work productivity. RESULTS: A total of 10,264 adults with either knee (n=3796) or low back (n=6468) pain for at least three months were included in the study. Participants experienced a 68.45% average improvement in VAS pain between baseline intake and 12 weeks. In all, 73.04% (7497/10,264) participants completed the DCP into the final month. In total, 78.60% (5893/7497) of program completers (7144/10,264, 69.60% of all participants) achieved minimally important change in pain. Furthermore, the number of ET sessions and coaching interactions were both positively associated with improvement in pain, suggesting that the amount of engagement influenced outcomes. Secondary outcomes included a 57.9% and 58.3% decrease in depression and anxiety scores, respectively, and 61.5% improvement in work productivity. Finally, 3 distinct clusters of pain response trajectories were identified, which could be predicted with a mean 76% accuracy using baseline measures. CONCLUSIONS: These results support the efficacy and scalability of a DCP for chronic low back and knee pain in a large, diverse, real-world population. Participants demonstrated high completion and engagement rates and a significant positive relationship between engagement and pain reduction was identified, a finding that has not been previously demonstrated in a DCP. Furthermore, the large sample size allowed for the identification of distinct pain response subgroups, which may prove beneficial in predicting recovery and tailoring future interventions. This is the first longitudinal digital health study to analyze pain outcomes in a sample of this magnitude, and it supports the prospect for DCPs to serve the overwhelming number of musculoskeletal pain sufferers worldwide.

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

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

Guidelines for Composing and Assessing a Paper on the Treatment of Pain: A Practical Application of Evidence-Based Medicine Principles to the Mint Randomized Clinical Trials.

Objective: To perform a thorough assessment of the recently published Mint Trials in order to illustrate how to read and analyze a study critically, according to principles of evidence-based medicine. Design: Narrative review. Method: We have applied the recently published guidelines for composing and assessing studies on the treatment of pain to a recently published article describing a large study that claimed its "findings do not support the use of radiofrequency denervation to treat chronic low back pain." These guidelines describe the critical components of a high-quality manuscript that allows communication of all relevant information from authors to readers. Results: Application of evidence-based medicine principles to the publication describing the Mint Trials reveals significant issues with the methodology and conclusions drawn by the authors. A thorough assessment demonstrates issues with inclusion/exclusion criteria, diagnostic block protocols, radiofrequency neurotomy technique, co-interventions, outcome measurement, power analysis, study sample characteristics, data analysis, and loss to follow-up. A failure to definitively establish a diagnosis, combined with use of an inadequate technique for radiofrequency neurotomy and numerous other methodological flaws, leaves the reader unable to draw meaningful conclusions from the study data. Conclusions: Critical analysis, rooted in principles of evidence-based medicine, must be employed by writers and readers alike in order to encourage transparency and ensure that appropriate conclusions are drawn from study data.

The Global Spine Care Initiative: public health and prevention interventions for common spine disorders in low- and middle-income communities.

PURPOSE: The purpose of this study was to develop recommendations for prevention interventions for spinal disorders that could be delivered globally, but especially in underserved areas and in low- and middle-income countries. METHODS: We extracted risk factors, associations, and comorbidities of common spinal disorders (e.g., back and neck pain, spinal trauma, infection, developmental disorders) from a scoping review of meta-analyses and systematic reviews of clinical trials, cohort studies, case control studies, and cross-sectional studies. Categories were informed by the Global Spine Care Initiative (GSCI) classification system using the biopsychosocial model. Risk factors were clustered and mapped visually. Potential prevention interventions for individuals and communities were identified. RESULTS: Forty-one risk factors, 51 associations, and 39 comorbidities were extracted; some were associated with more than one disorder. Interventions were at primary, secondary, tertiary, and quaternary prevention levels. Public health-related actions included screening for osteopenia, avoiding exposure to certain substances associated with spinal disorders, insuring adequate dietary intake for vitamins and minerals, smoking cessation, weight management, injury prevention, adequate physical activity, and avoiding harmful clinical practices (e.g., over-medicalization). CONCLUSION: Prevention principles and health promotion strategies were identified that were incorporated in the GSCI care pathway. Interventions should encourage healthy behaviors of individuals and promote public health interventions that are most likely to optimize physical and psychosocial health targeting the unique characteristics of each community. Prevention interventions that are implemented in medically underserved areas should be based upon best evidence, resource availability, and selected through group decision-making processes by individuals and the community. These slides can be retrieved under Electronic Supplementary Material.

Reliability and Validity of Athletes Disability Index Questionnaire.

OBJECTIVE: The purpose of this study was to evaluate validity and reliability of a new proposed questionnaire for assessment of functional disability in athletes with low back pain (LBP). DESIGN: Validity and reliability study. SETTING: Elite athletes participating in different fields of sports. PARTICIPANTS: Participants were 165 male and female athletes (between 12 and 50 years old) with LBP. INTERVENTIONS: Athlete Disability Index (ADI) Questionnaire which is developed by the authors for assessing LBP-related disability in athletes, Oswestry Disability Index (ODI), and the Roland-Morris Disability Questionnaire (RDQ). MAIN OUTCOME MEASURES: Self-reported responses were collected regarding LBP-related disability through ADI, ODI, and RDQ. RESULTS: The test-retest reliability was strong, and intraclass correlation value ranged between 0.74 and 0.94. The Cronbach alpha coefficient value of 0.91 (P < 0.001) demonstrated excellent internal consistency of the questionnaire. The correlation coefficient between ADI and ODI was r = 0.918 (P < 0.0001), between ADI and RDQ was r = 0.669 (P < 0.0001), and between ADI and visual analog scale was r = 0.626 (P < 0.001). According to ODI and RDQ, disability levels were mild in the large majority of subjects (91.5% and 86.0%, respectively). Alternatively, disability assessments by the ADI did not cluster at the mild level and ranged more broadly from mild to very high. CONCLUSION: The ADI is a reliable and valid instrument for assessing disability in athletes with LBP. Compared with the available LBP disability questionnaires used in the general population, ADI can more precisely stratify the disability levels of athletes due to LBP.

Gait Symmetry Assessment with a Low Back 3D Accelerometer in Post-Stroke Patients.

Gait asymmetry is an important marker of mobility impairment post stroke. This study proposes a new gait symmetry index (GSI) to quantify gait symmetry with one 3D accelerometer at L3 (GSIL3). GSIL3 was evaluated with 16 post stroke patients and nine healthy controls in the Six-Minute-Walk-Test (6-MWT). Discriminative power was evaluated with Wilcoxon test and the effect size (ES) was computed with Cliff's Delta. GSIL3 estimated during the entire 6-MWT and during a short segment straight walk (GSIL3straight) have comparable effect size to one another (ES = 0.89, p < 0.001) and to the symmetry indices derived from feet sensors (|ES| = [0.22, 0.89]). Furthermore, while none of the indices derived from feet sensors showed significant differences between post stroke patients walking with a cane compared to those able to walk without, GSIL3 was able to discriminate between these two groups with a significantly lower value in the group using a cane (ES = 0.70, p = 0.02). In addition, GSIL3 was strongly associated with several symmetry indices measured by feet sensors during the straight walking cycles (Spearman correlation: |ρ| = [0.82, 0.88], p < 0.05). The proposed index can be a reliable and cost-efficient post stroke gait symmetry assessment with implications for research and clinical practice.

A randomized trial of epidural glucocorticoid injections for spinal stenosis.

BACKGROUND: Epidural glucocorticoid injections are widely used to treat symptoms of lumbar spinal stenosis, a common cause of pain and disability in older adults. However, rigorous data are lacking regarding the effectiveness and safety of these injections. METHODS: In a double-blind, multisite trial, we randomly assigned 400 patients who had lumbar central spinal stenosis and moderate-to-severe leg pain and disability to receive epidural injections of glucocorticoids plus lidocaine or lidocaine alone. The patients received one or two injections before the primary outcome evaluation, performed 6 weeks after randomization and the first injection. The primary outcomes were the score on the Roland-Morris Disability Questionnaire (RMDQ, in which scores range from 0 to 24, with higher scores indicating greater physical disability) and the rating of the intensity of leg pain (on a scale from 0 to 10, with 0 indicating no pain and 10 indicating "pain as bad as you can imagine"). RESULTS: At 6 weeks, there were no significant between-group differences in the RMDQ score (adjusted difference in the average treatment effect between the glucocorticoid-lidocaine group and the lidocaine-alone group, -1.0 points; 95% confidence interval [CI], -2.1 to 0.1; P=0.07) or the intensity of leg pain (adjusted difference in the average treatment effect, -0.2 points; 95% CI, -0.8 to 0.4; P=0.48). A prespecified secondary subgroup analysis with stratification according to type of injection (interlaminar vs. transforaminal) likewise showed no significant differences at 6 weeks. CONCLUSIONS: In the treatment of lumbar spinal stenosis, epidural injection of glucocorticoids plus lidocaine offered minimal or no short-term benefit as compared with epidural injection of lidocaine alone. (Funded by the Agency for Healthcare Research and Quality; ClinicalTrials.gov number, NCT01238536.).

The Impact of Body Mass Index on Fluoroscopy Time During Lumbar Epidural Steroid Injection; A Multicenter Cohort Study.

Objective: This study aimed to assess the relationship between BMI and fluoroscopy time during lumbar epidural steroid injections (LESIs) performed for lumbosacral radicular pain. Design: Multicenter retrospective cohort study. Setting: Three academic, outpatient pain treatment centers. Subjects: Patients who underwent fluoroscopically guided LESI. Methods: Mean and standard deviation (SD) fluoroscopy time were compared between patients with normal (18.5-24.9 kg/m2), overweight (25.0-29.9 kg/m2), and obese (≥30.0 kg/m2) BMI. Statistical significance was set at P=0.01 due to multiple comparisons. Results: A total of 2,930 procedure encounters were included, consisting of 598 interlaminar LESIs and 2,332 transforaminal LESIs. Fluoroscopy time was significantly longer in the obese patients compared to normal and overweight patients during interlaminar LESI (P < 0.01). Fluoroscopy time was significantly longer with each increasing BMI category in during transforaminal LESI (P < 0.01). These relationships remained when a trainee was involved (P < 0.01; P<0.01), during repeat injections (P < 0.01; P < 0.01), and during bilateral transforaminal LESIs (P < 0.01). While longer fluoroscopy times were required in high BMI categories during L5-S1 transforaminal LESI (P < 0.01), there was no relationship between fluoroscopy time and BMI during L4-L5 and S1 transforaminal LESI (P = 0.02; P = 0.13). Fluoroscopy time during interlaminar LESI compared to transforaminal LESI was significantly lower within all BMI categories (all P<0.01). Conclusions: The findings of this study indicate that fluoroscopy time is increased during interlaminar LESIs and during L5-S1 transforaminal LESIs in patients who are obese. These relationships are not affected by injection number, performance of bilateral injections, or trainee involvement. Further study is needed to determine if this increase in fluoroscopy time is indicative of a clinically significant associated increase in radiation dose.

Is There a Relationship Between Body Mass Index and Fluoroscopy Time During Cervical Interlaminar Epidural Steroid Injections?

BACKGROUND: The challenge of obtaining medical imaging in individuals with higher body mass index (BMI) is described, but there is minimal data regarding the relationship between BMI and fluoroscopy time during cervical interlaminar epidural steroid injection (CIESI). OBJECTIVE: To determine the relationship between BMI and fluoroscopy time during CIESI. METHODS: Retrospective cohort study of patients who underwent fluoroscopically guided CIESI between January 2014 and February 2015 at an academic pain medicine center. Fluoroscopy time data were collected. Comparisons based on analysis of variance were made between patients with normal (<25.0 kg/m 2 ), overweight (25.0-29.9 kg/m 2 ), and obese (≥30.0 kg/m 2 ) BMI. RESULTS: Of 399 procedure encounters, 366 had documented BMI and fluoroscopy time data and were included for analysis. Mean age (± SD) in this cohort was 53 ± 13 years, including 189 females (52%) and 205 first-time injections. Mean fluoroscopy time for all injections was 18 ± 10 seconds. Separated by categorical BMI class, the mean fluoroscopy time was 18 ± 9 seconds for normal weight patients, 17 ± 10 seconds for overweight patients, and 20 ± 11 seconds for obese patients, respectively. Post hoc analysis showed that fluoroscopy time was significantly longer only in obese compared with overweight patients ( P = 0.02). Trainee involvement and first-time vs repeat injection did not significantly alter fluoroscopy time ( P = 0.17 and P = 0.12, respectively). CONCLUSIONS: The findings of this study indicate that BMI does not appear to have a clinically significant impact on fluoroscopy time during cervical interlaminar epidural steroid injection procedures. Future study is needed to directly quantify radiation exposure in patients and practitioners, as well as the associated health risk.

Long-Term Effects of Repeated Injections of Local Anesthetic With or Without Corticosteroid for Lumbar Spinal Stenosis: A Randomized Trial.

OBJECTIVE: To determine the overall long-term effectiveness of treatment with epidural corticosteroid injections for lumbar central spinal stenosis and the effect of repeat injections, including crossover injections, on outcomes through 12 months. DESIGN: Multicenter, double-blind, randomized controlled trial comparing epidural injections of corticosteroid plus lidocaine versus lidocaine alone. SETTING: Sixteen clinical sites. PARTICIPANTS: Participants with imaging-confirmed lumbar central spinal stenosis (N=400). INTERVENTIONS: Participants were randomized to receive either epidural injections with corticosteroid plus lidocaine or lidocaine alone with the option of blinded crossover after 6 weeks to receive the alternate treatment. Participants could receive 1 to 2 injections from 0 to 6 weeks and up to 2 injections from 6 to 12 weeks. After 12 weeks, participants received usual care. MAIN OUTCOME MEASURES: Primary outcomes were the Roland-Morris Disability Questionnaire (RDQ) (range, 0-24, where higher scores indicate greater disability) and leg pain intensity (range, 0 [no pain] to 10 [pain as bad as you can imagine]). Secondary outcomes included opioid use, spine surgery, and crossover rates. RESULTS: At 12 months, both treatment groups maintained initial observed improvements, with no significant differences between groups on the RDQ (adjusted mean difference, -0.4; 95% confidence interval [CI], -1.6 to 0.9; P=.55), leg pain (adjusted mean difference, 0.1; 95% CI, -0.5 to 0.7; P=.75), opioid use (corticosteroid plus lidocaine: 41.4% vs lidocaine alone: 36.3%; P=.41), or spine surgery (corticosteroid plus lidocaine: 16.8% vs lidocaine alone: 11.8%; P=.22). Fewer participants randomized to corticosteroid plus lidocaine (30%, n=60) versus lidocaine alone (45%, n=90) crossed over after 6 weeks (P=.003). Among participants who crossed over at 6 weeks, the 6- to 12-week RDQ change did not differ between the 2 randomized treatment groups (adjusted mean difference, -1.0; 95% CI, -2.6 to 0.7; P=.24). In both groups, participants crossing over at 6 weeks had worse 12-month trajectories compared with participants who did not choose to crossover. CONCLUSIONS: For lumbar spinal stenosis symptoms, epidural injections of corticosteroid plus lidocaine offered no benefits from 6 weeks to 12 months beyond that of injections of lidocaine alone in terms of self-reported pain and function or reduction in use of opioids and spine surgery. In patients with improved pain and function 6 weeks after initial injection, these outcomes were maintained at 12 months. However, the trajectories of pain and function outcomes after 3 weeks did not differ by injectate type. Repeated injections of either type offered no additional long-term benefit if injections in the first 6 weeks did not improve pain.

The Effects of Local Anesthesia Administration on Pain Experience During Interventional Spine Procedures: A Prospective Controlled Trial.

OBJECTIVE: It has been postulated that local anesthetic administration may be the most painful part of interventional spine procedures. Despite this, there is a lack of evidence supporting the commonly used traditional technique of anesthetic delivery as part of these procedures. This study tested three hypotheses: 1) alternative method of local anesthesia injection is superior to the traditional method; 2) using the traditional method of injection is not superior to using no local anesthetic; and 3) treatment needle size, anesthetic injection technique, and sedation are associated with pain experienced during procedures. DESIGN: Prospective, multicenter clinical trial of 127 participants who underwent elective bilateral symmetric interventional spine procedures in outpatient spine clinics. METHODS: Primary outcomes were pain scores during and after procedures to examine the influence of anesthetic injection method and treatment needle gauge on pain experience using linear mixed model regression analysis. A post-hoc comparison of estimated marginal mean pain scores was completed on both anesthetic injection method and treatment needle gauge. CONCLUSIONS: The alternative method was superior (P < 0.05) to the traditional method on post procedural pain scores. Injecting local anesthetic with the traditional or alternative method was not superior to using no local anesthetic. Treatment needle size, pain at one inch of treatment needle insertion, and baseline pain were all significantly (P < 0.05) associated with overall procedural pain. Further studies are needed optimize and justify local anesthetic injections for these procedures.