Waddell (Nonorganic) Signs and Their Association With Interventional Treatment Outcomes for Low Back Pain.

BACKGROUND: The rising use of injections to treat low back pain (LBP) has led to efforts to improve selection. Nonorganic (Waddell) signs have been shown to portend treatment failure for surgery and other therapies but have not been studied for minimally invasive interventions. METHODS: We prospectively evaluated the association between Waddell signs and treatment outcome in 3 cohorts: epidural steroid injections (ESI) for leg pain and sacroiliac joint (SIJ) injections and facet interventions for LBP. Categories of Waddell signs included nonanatomic tenderness, pain during sham stimulation, discrepancy in physical examination, overreaction, and regional disturbances divulging from neuroanatomy. The primary outcome was change in patient-reported "average" numerical rating scale for pain intensity (average NRS-PI), modeled as a function of the number of Waddell signs using simple linear regression. Secondary outcomes included a binary indicator of treatment response. We conducted secondary and sensitivity analyses to account for potential confounders. RESULTS: We enrolled 318 patients: 152 in the ESI cohort, 102 in the facet cohort, and 64 in the SIJ cohort, having sufficient data for primary analysis on 308 patients. Among these, 62% (n = 192) had no Waddell signs, 18% (n = 54) had 1 sign, 11% (n = 33) had 2, 5% (n = 16) had 3, 2% (n = 7) had 4, and about 2% (n = 6) had all 5 signs. The mean change in average NRS-PI in each of these 6 groups was -1.6 ± 2.6, -1.1 ± 2.7, -1.5 ± 2.5, -1.6 ± 2.6, -1 ± 1.5, and 0.7 ± 2.1, respectively, and their corresponding treatment failure rates were 54% (102 of 192), 67% (36 of 54), 70% (23 of 33), 75% (12 of 16), 71% (5 of 7), and 83% (5 of 6). In the primary analysis, an increasing number of Waddell signs were not associated with a significant decrease in average NRS-PI (coefficient [Coef] = 0.19; 95% confidence interval [CI], -0.43 to 0.05; P = .12). A higher number of Waddell signs were associated with treatment failure, with a 1.35 increased odds of treatment failure per cumulative number of signs (P = .008). CONCLUSIONS: Whereas this study found no consistent relationship between Waddell signs and decreased mean pain scores, a significant relationship between the number of Waddell signs and treatment failure was observed.

Compounded Topical Pain Creams to Treat Localized Chronic Pain: A Randomized Controlled Trial.

Background: The use of compounded topical pain creams has increased dramatically, yet their effectiveness has not been well evaluated. Objective: To determine the efficacy of compounded creams for chronic pain. Design: Randomized controlled trials of 3 interventions. (ClinicalTrials.gov: NCT02497066). Setting: Military treatment facility. Participants: 399 patients with localized pain classified by each patient's treating physician as neuropathic (n = 133), nociceptive (n = 133), or mixed (n = 133). Intervention: Pain creams compounded for neuropathic pain (ketamine, gabapentin, clonidine, and lidocaine), nociceptive pain (ketoprofen, baclofen, cyclobenzaprine, and lidocaine), or mixed pain (ketamine, gabapentin, diclofenac, baclofen, cyclobenzaprine, and lidocaine), or placebo. Measurements: The primary outcome measure was average pain score 1 month after treatment. A positive categorical response was a reduction in pain score of 2 or more points coupled with a score above 3 on a 5-point satisfaction scale. Secondary outcomes included Short Form-36 Health Survey scores, satisfaction, and categorical response. Participants with a positive outcome were followed through 3 months. Results: For the primary outcome, no differences were found in the mean reduction in average pain scores between the treatment and control groups for patients with neuropathic pain (-0.1 points [95% CI, -0.8 to 0.5 points]), nociceptive pain (-0.3 points [CI, -0.9 to 0.2 points]), or mixed pain (-0.3 points [CI, -0.9 to 0.2 points]), or for all patients (-0.3 points [CI, -0.6 to 0.1 points]). At 1 month, 72 participants (36%) in the treatment groups and 54 (28%) in the control group had a positive outcome (risk difference, 8% [CI, -1% to 17%]). Limitations: Generalizability is limited by heterogeneity among pain conditions and formulations of the study interventions. Randomized follow-up was only 1 month. Conclusion: Compounded pain creams were not better than placebo creams, and their higher costs compared with approved compounds should curtail routine use. Primary Funding Source: Centers for Rehabilitation Sciences Research, Defense Health Agency, U.S. Department of Defense.

Effectiveness of Lumbar Facet Joint Blocks and Predictive Value before Radiofrequency Denervation: The Facet Treatment Study (FACTS), a Randomized, Controlled Clinical Trial.

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: WHAT THIS ARTICLE TELLS US THAT IS NEW: BACKGROUND:: With facet interventions under scrutiny, the authors' objectives were to determine the effectiveness of different lumbar facet blocks and their ability to predict radiofrequency ablation outcomes. METHODS: A total of 229 participants were randomized in a 2:2:1 ratio to receive intraarticular facet injections with bupivacaine and steroid, medial branch blocks, or saline. Those with a positive 1-month outcome (a 2-point or more reduction in average pain score) and score higher than 3 (positive satisfaction) on a 5-point satisfaction scale were followed up to 6 months. Participants in the intraarticular and medial branch block groups with a positive diagnostic block (50% or more relief) who experienced a negative outcome proceeded to the second phase and underwent radiofrequency ablation, while all saline group individuals underwent ablation. Coprimary outcome measures were average reduction in numerical rating scale pain score 1 month after the facet or saline blocks, and average numerical rating scale pain score 3 months after ablation. RESULTS: Mean reduction in average numerical rating scale pain score at 1 month was 0.7 ± 1.6 in the intraarticular group, 0.7 ± 1.8 in the medial branch block group, and 0.7 ± 1.5 in the placebo group; P = 0.993. The proportions of positive blocks were higher in the intraarticular (54%) and medial branch (55%) groups than in the placebo group (30%; P = 0.01). Radiofrequency ablation was performed on 135 patients (45, 48, and 42 patients from the intraarticular, medial branch, and saline groups, respectively). The average numerical rating scale pain score at 3 months was 3.0 ± 2.0 in the intraarticular, 3.2 ± 2.5 in the medial branch, and 3.5 ± 1.9 in the control group (P = 0.493). At 3 months, the proportions of positive responders in the intraarticular, medial branch block, and placebo groups were 51%, 56%, and 24% for the intraarticular, medial branch, and placebo groups, respectively (P = 0.005). CONCLUSIONS: This study establishes that facet blocks are not therapeutic. The higher responder rates in the treatment groups suggest a hypothesis that facet blocks might provide prognostic value before radiofrequency ablation.

Epidural steroid injections, conservative treatment, or combination treatment for cervical radicular pain: a multicenter, randomized, comparative-effectiveness study.

BACKGROUND: Cervical radicular pain is a major cause of disability. No studies have been published comparing different types of nonsurgical therapy. METHODS: A comparative-effectiveness study was performed in 169 patients with cervical radicular pain less than 4 yr in duration. Participants received nortriptyline and/or gabapentin plus physical therapies, up to three cervical epidural steroid injections (ESI) or combination treatment over 6 months. The primary outcome measure was average arm pain on a 0 to 10 scale at 1 month. RESULTS: One-month arm pain scores were 3.5 (95% CI, 2.8 to 4.2) in the combination group, 4.2 (CI, 2.8 to 4.2) in ESI patients, and 4.3 (CI, 2.8 to 4.2) in individuals treated conservatively (P = 0.26). Combination group patients experienced a mean reduction of -3.1 (95% CI, -3.8 to -2.3) in average arm pain at 1 month versus -1.8 (CI, -2.5 to -1.2) in the conservative group and -2.0 (CI, -2.7 to -1.3) in ESI patients (P = 0.035). For neck pain, a mean reduction of -2.2 (95% CI, -3.0 to -1.5) was noted in combination patients versus -1.2 (CI, -1.9 to -0.5) in conservative group patients and -1.1 (CI, -1.8 to -0.4) in those who received ESI; P = 0.064). Three-month posttreatment, 56.9% of patients treated with combination therapy experienced a positive outcome versus 26.8% in the conservative group and 36.7% in ESI patients (P = 0.006). CONCLUSIONS: For the primary outcome measure, no significant differences were found between treatments, although combination therapy provided better improvement than stand-alone treatment on some measures. Whereas these results suggest an interdisciplinary approach to neck pain may improve outcomes, confirmatory studies are needed.

The effect of sedation on the accuracy and treatment outcomes for diagnostic injections: a randomized, controlled, crossover study.

BACKGROUND AND OBJECTIVE: Diagnostic injections are used to diagnose myriad pain conditions, but are characterized by a high false-positive rate. One potential cause of inaccurate diagnostic blocks is the use of sedation. We sought to determine the effect of sedation on the validity of diagnostic injections. DESIGN: Randomized, crossover study in which 73 patients were allocated to receive a diagnostic sacroiliac joint or sympathetic nerve block performed either with or without sedation using midazolam and fentanyl. Those who obtained equivocal relief, good relief lasting less than 3 months, or who were otherwise deemed good candidates for a repeat injection, received a subsequent crossover injection within 3 months (N = 46). SETTING AND PATIENTS: A tertiary care teaching hospital and a military treatment facility. RESULTS: In the primary crossover analysis, blocks performed with sedation resulted in a larger mean reduction in pain diary score than those done without sedation (1.2 [2.6]; P = 0.006), less procedure-related pain (difference in means 2.3 [2.5]; P < 0.0001), and a higher proportion of patients who obtained > 50% pain relief on their pain diaries (70% vs. 54%; P = 0.039). The increased pain reduction was not accompanied by increased satisfaction (sedation mean 3.9 [1.1] vs. 3.7 [1.3]; P = 0.26). Similar findings were observed for the parallel group (N = 73) and omnibus (all sedation vs. no sedation blocks, N = 110) analyses. No differences in outcomes were noted between the use and non-use of sedation at 1-month. CONCLUSIONS: The use of sedation during diagnostic injections may increase the rate of false-positive blocks and lead to misdiagnoses and unnecessary procedures, but has no effect on satisfaction or outcomes at 1-month.

A multicenter, randomized, controlled study evaluating preventive etanercept on postoperative pain after inguinal hernia repair.

BACKGROUND: Chronic postsurgical pain (CPSP) affects between 5% and 70% of surgical patients, depending on the surgery. There is no reliable treatment for CPSP, which has led to an increased emphasis on prevention. In this study, we sought to determine whether preventive etanercept can decrease the magnitude of postoperative pain and reduce the incidence of CPSP. METHODS: We performed a multicenter, randomized study in 77 patients comparing subcutaneous etanercept 50 mg administered 90 minutes before inguinal hernia surgery with saline. Patients, surgeons, anesthesiologists, the injecting physician, nursing staff, and evaluators were blinded. The primary outcome measure was a 24-hour numerical rating scale pain score. Secondary outcome measures were postanesthesia care unit pain scores, 24-hour opioid requirements, time to first analgesic, and pain scores recorded at 1 month, 3 months, 6 months, and 12 months. RESULTS: Mean 24-hour pain scores were 3.3 (95% confidence interval [CI], 3.2-4.6) in the etanercept and 3.9 (95% CI, 2.6-4.0) in the control group (P=0.22). The mean number of analgesic pills used in the first 24 hours was 4.0 (SD, 2.8) in the treatment versus 5.8 (SD, 4.2) in the control group (P=0.03). At 1 month, 10 patients (29%) in the treatment group reported pain versus 21 (49%) control patients (P=0.08). The presence of pain at 1 month was significantly associated with pain at 3 months (hazard ratio, 0.74; 99% CI, 0.52-0.97; P=0.03). CONCLUSION: Although preventive etanercept was superior to saline in reducing postoperative pain on some measures, the effect sizes were small, transient, and not statistically significant. Different dosing regimens in a larger population should be explored in future studies.

Does pain score in response to a standardized subcutaneous local anesthetic injection predict epidural steroid injection outcomes in patients with lumbosacral radiculopathy? A prospective correlational study.

OBJECTIVE: Epidural steroid injections (ESI) are the most commonly performed pain procedures. Despite numerous studies, controversy continues to surround their effectiveness. The purpose of this study is to determine whether a standard, clinical local anesthetic injection can predict outcomes for ESI. STUDY DESIGN: In this multicenter study, 103 patients received two ESI 2 weeks apart. Prior to their first injection, subjects rated the pain intensity of a standardized subcutaneous (SQ) injection of lidocaine prior to the full dose. Numerical rating scale pain scores were correlated with leg and back pain relief, and functional improvement, through 3-month follow-up. OUTCOME MEASURES: A composite successful outcome was predetermined to be a ≥2-point decrease in leg pain score, coupled with a positive global perceived effect. RESULTS: A small but significant relationship was found between SQ pain score and reduction in leg (r = -0.21, 95% CI -0.38 to -0.04; P = 0.03) and back pain (r = -0.22, 95% CI -0.36 to -0.07; P = 0.03). Subjects with a positive outcome at 1 month had a mean SQ pain score of 2.5 (SD 1.9) vs 4.1 (SD 2.7) in those with a negative outcome (P = 0.04). Subjects with SQ pain scores <4/10 had lower leg and back pain scores than those with pain scores ≥4 at 1-month (mean 3.2, SD 2.6 vs 5.1, SD 2.7 for leg, P < 0.01; mean 3.7, SD 2.6 vs 5.0, SD 3.0 for back, P = 0.02) and 3-month (mean 3.8, SD 2.7 vs 5.2, SD 3.1 for leg, P = 0.01; mean 4.0, SD 2.6 vs 4.9, SD 3.1 for back; P = 0.14) follow-up. CONCLUSIONS: The results of this study found a weak positive correlation between SQ pain scores and treatment results. Further research should consider whether pain perception in conjunction with other variables might prove to be a reliable predictor for ESI and other procedural outcomes.

Epidural steroids, etanercept, or saline in subacute sciatica: a multicenter, randomized trial.

BACKGROUND: Perineural inhibitors of tumor necrosis factor have recently generated intense interest as an alternative to epidural steroid injections for lumbosacral radiculopathy. OBJECTIVE: To evaluate whether epidural steroids, etanercept, or saline better improves pain and function in adults with lumbosacral radiculopathy. DESIGN: A multicenter, 3-group, randomized, placebo-controlled trial conducted from 2008 to 2011. Randomization was computer-generated and stratified by site. Pharmacists prepared the syringes. Patients, treating physicians, and nurses assessing outcomes were blinded to treatment assignment. (ClinicalTrials.gov registration number: NCT00733096) SETTING: Military and civilian treatment centers. PATIENTS: 84 adults with lumbosacral radiculopathy of less than 6 months' duration. INTERVENTION: 2 epidural injections of steroids, etanercept, or saline, mixed with bupivacaine and separated by 2 weeks. MEASUREMENTS: The primary outcome measure was leg pain 1 month after the second injection. All patients had 1-month follow-up visits; patients whose condition improved remained blinded for the 6-month study period. RESULTS: The group that received epidural steroids had greater reductions in the primary outcome measure than those who received saline (mean difference, -1.26 [95% CI, -2.79 to 0.27]; P = 0.11) or etanercept (mean difference, -1.01 [CI, -2.60 to 0.58]; P = 0.21). For back pain, smaller differences favoring steroids compared with saline (mean difference, -0.52 [CI, -1.85 to 0.81]; P = 0.44) and etanercept (mean difference, -0.92 [CI,-2.28 to 0.44]; P = 0.18) were observed. The largest differences were noted for functional capacity, in which etanercept fared worse than the other treatments: steroids vs. etanercept (mean difference, -16.16 [CI, -26.05 to -6.27]; P = 0.002), steroids vs. saline (mean difference, -5.87 [CI, -15.59 to 3.85]; P = 0.23), and etanercept vs. saline (mean difference, 10.29 [CI, 0.55 to 20.04]; P = 0.04). More patients treated with epidural steroids (75%) reported 50% or greater leg pain relief and a positive global perceived effect at 1 month than those who received saline (50%) or etanercept (42%) (P = 0.09). LIMITATION: Short-term follow-up, small sample size, and a possibly subtherapeutic dose of etanercept. CONCLUSION: Epidural steroid injections may provide modest short-term pain relief for some adults with lumbosacral radiculopathy, but larger studies with longer follow-up are needed to confirm their benefits. PRIMARY FUNDING SOURCE: The John P. Murtha Neuroscience and Pain Institute, International Spinal Intervention Society, and Center for Rehabilitation Sciences Research.

Headaches during war: analysis of presentation, treatment, and factors associated with outcome.

BACKGROUND: Headache is often associated with physical trauma and psychological stress. The aim of this study is to evaluate the impact of headache on personnel deployed in war zones and to identify factors associated with return to duty (RTD). METHODS: Outcome data were prospectively collected on 985 personnel medically evacuated out of Operations Iraqi and Enduring Freedom for a primary diagnosis of headache between 2004 and 2009. Electronic medical records were reviewed to examine clinical and treatment patterns and the effect that myriad factors had on RTD. RESULTS: 33.6% of evacuees returned to duty. The most common headaches were post-concussion (34.1%) and migraine (30.0%). Headaches typically associated with trauma such as post-concussion (18.7%), occipital neuralgia (23.1%), and cervicogenic headache (29.7%) had the lowest RTD rates, whereas tension headache (49.6%) was associated with the best outcome. Other variables associated with negative outcome included presence of aura (OR 0.51, 95% CI 0.30-0.88; p = 0.02), traumatic brain injury (OR 0.50, 95% CI 0.29-0.87; p = 0.01), opioid (OR 0.41, 95% CI 0.26-0.63; p < 0.001), and beta-blocker (OR 0.26, 95% CI 0.12-0.61; p = 0.002) use, and co-existing psychopathology (p < 0.001 in univariable analysis). CONCLUSION: Headaches represent a significant cause of unit attrition in personnel deployed in military operations, with physical trauma and co-existing psychopathology associated with poorer outcomes.

Multicenter study evaluating factors associated with treatment outcome for low back pain injections.

BACKGROUND: There has been a worldwide surge in interventional procedures for low back pain (LBP), with studies yielding mixed results. These data support the need for identifying outcome predictors based on unique characteristics in a pragmatic setting. METHODS: We prospectively evaluated the association between over two dozen demographic, clinical and technical factors on treatment outcomes for three procedures: epidural steroid injections (ESIs) for sciatica, and sacroiliac joint (SIJ) injections and facet interventions for axial LBP. The primary outcome was change in patient-reported average pain intensity on a numerical rating scale (average NRS-PI) using linear regression. For SIJ injections and facet radiofrequency ablation, this was average LBP score at 1 and 3 months postprocedure, respectively. For ESI, it was average leg pain 1- month postinjection. Secondary outcomes included a binary indicator of treatment response (success). RESULTS: 346 patients were enrolled at seven hospitals. All groups experienced a decrease in average NRS-PI (p<0.0001; mean 1.8±2.6). There were no differences in change in average NRS-PI among procedural groups (p=0.50). Lower baseline pain score (adjusted coefficient -0.32, 95% CI -0.48 to -0.16, p<0.0001), depressive symptomatology (adjusted coefficient 0.076, 95% CI 0.039 to 0.113, p<0.0001) and obesity (adjusted coefficient 0.62, 95% CI 0.038 to 1.21, p=0.037) were associated with smaller pain reductions. For procedural outcome, depression (adjusted OR 0.94, 95% CI 0.91, 0.97, p<0.0001) and poorer baseline function (adjusted OR 0.59, 95% CI 0.36, 0.96, p=0.034) were associated with failure. Smoking, sleep dysfunction and non-organic signs were associated with negative outcomes in univariate but not multivariate analyses. CONCLUSIONS: Identifying treatment responders is a critical endeavor for the viability of procedures in LBP. Patients with greater disease burden, depression and obesity are more likely to fail interventions. Steps to address these should be considered before or concurrent with procedures as considerations dictate. TRIAL REGISTRATION NUMBER: NCT02329951.

Diagnoses and factors associated with medical evacuation and return to duty for service members participating in Operation Iraqi Freedom or Operation Enduring Freedom: a prospective cohort study.

BACKGROUND: Anticipation of the types of injuries that occur in modern warfare is essential to plan operations and maintain a healthy military. We aimed to identify the diagnoses that result in most medical evacuations, and ascertain which demographic and clinical variables were associated with return to duty. METHODS: Demographic and clinical data were prospectively obtained for US military personnel who had been medically evacuated from Operation Iraqi Freedom or Operation Enduring Freedom (January, 2004-December, 2007). Diagnoses were categorised post hoc according to the International Classification of Diseases codes that were recorded at the time of transfer. The primary outcome measure was return to duty within 2 weeks. FINDINGS: 34 006 personnel were medically evacuated, of whom 89% were men, 91% were enlisted, 82% were in the army, and 86% sustained an injury in Iraq. The most common reasons for medical evacuation were: musculoskeletal and connective tissue disorders (n=8104 service members, 24%), combat injuries (n=4713, 14%), neurological disorders (n=3502, 10%), psychiatric diagnoses (n=3108, 9%), and spinal pain (n=2445, 7%). The factors most strongly associated with return to duty were being a senior officer (adjusted OR 2.01, 95% CI 1.71-2.35, p<0.0001), having a non-battle-related injury or disease (3.18, 2.77-3.67, p<0.0001), and presenting with chest or abdominal pain (2.48, 1.61-3.81, p<0.0001), a gastrointestinal disorder (non-surgical 2.32, 1.51-3.56, p=0.0001; surgical 2.62, 1.69-4.06, p<0.0001), or a genitourinary disorder (2.19, 1.43-3.36, p=0.0003). Covariates associated with a decreased probability of return to duty were serving in the navy or coast guard (0.59, 0.45-0.78, p=0.0002), or marines (0.86, 0.77-0.96, p=0.0083); and presenting with a combat injury (0.27, 0.17-0.44, p<0.0001), a psychiatric disorder (0.28, 0.18-0.43, p<0.0001), musculoskeletal or connective tissue disorder (0.46, 0.30-0.71, p=0.0004), spinal pain (0.41, 0.26-0.63, p=0.0001), or other wound (0.54, 0.34-0.84, p=0.0069). INTERPRETATION: Implementation of preventive measures for service members who are at highest risk of evacuation, forward-deployed treatment, and therapeutic interventions could reduce the effect of non-battle-related injuries and disease on military readiness. FUNDING: John P Murtha Neuroscience and Pain Institute, and US Army Regional Anesthesia and Pain Management Initiative.

Diagnoses and factors associated with medical evacuation and return to duty among nonmilitary personnel participating in military operations in Iraq and Afghanistan.

BACKGROUND: Nonmilitary personnel play an increasingly critical role in modern wars. Stark differences exist between the demographic characteristics, training and missions of military and nonmilitary members. We examined the differences in types of injury and rates of returning to duty among nonmilitary and military personnel participating in military operations in Iraq and Afghanistan. METHODS: We collected data for nonmilitary personnel medically evacuated from military operations in Iraq and Afghanistan between 2004 and 2007. We compared injury categories and return-to-duty rates in this group with previously published data for military personnel and identified factors associated with return to duty. RESULTS: Of the 2155 medically evacuated nonmilitary personnel, 74.7% did not return to duty. War-related injuries in this group accounted for 25.6% of the evacuations, the most common causes being combat-related injuries (55.4%) and musculoskeletal/spinal injuries (22.9%). Among individuals with non-war-related injuries, musculoskeletal injuries accounted for 17.8% of evacuations. Diagnoses associated with the highest return-to-duty rates in the group of nonmilitary personnel were psychiatric diagnoses (15.6%) among those with war-related injuries and noncardiac chest or abdominal pain (44.0%) among those with non-war-related injuries. Compared with military personnel, nonmilitary personnel with war-related injuries were less likely to return to duty (4.4% v. 5.9%, p = 0.001) but more likely to return to duty after non-war-related injuries (32.5% v. 30.7%, p = 0.001). INTERPRETATION: Compared with military personnel, nonmilitary personnel were more likely to be evacuated with non-war-related injuries but more likely to return to duty after such injuries. For evacuations because of war-related injuries, this trend was reversed.

Does sensory stimulation threshold affect lumbar facet radiofrequency denervation outcomes? A prospective clinical correlational study.

BACKGROUND: Radiofrequency facet denervation is one of the most frequently performed procedures for chronic low back pain. Although sensory stimulation is generally used as a surrogate measure to denote sufficient proximity of the electrode to the nerve, no study has examined whether stimulation threshold influences outcome. METHODS: We prospectively recorded data in 61 consecutive patients undergoing lumbar facet radiofrequency denervation who experienced significant pain relief after medial branch blocks. For each nerve lesioned, multiple attempts were made to maximize sensory stimulation threshold (SST). Mean SST was calculated on the basis of the lowest stimulation perceived at 0.1-V increments for each medial branch. A positive outcome was defined as a ≥50% reduction in back pain coupled with a positive satisfaction score lasting ≥3 months. The relationship between mean SST and denervation outcomes was evaluated via a receiver's operating characteristic (ROC) curve, and stratifying outcomes on the basis of various cutoff values. RESULTS: No correlation was noted between mean SST and pain relief at rest (Pearson's r=-0.01, 95% confidence interval [CI]: -0.24 to 0.23, P=0.97), with activity (r=-0.17, 95% CI: -0.40 to 0.07, P=0.20), or a successful outcome. No optimal SST could be identified. CONCLUSIONS: There is no significant relationship between mean SST during lumbar facet radiofrequency denervation and treatment outcome, which may be due to differences in general sensory perception. Because stimulation threshold was optimized for each patient, these data cannot be interpreted to suggest that sensory testing should not be performed, or that high sensory stimulation thresholds obtained on the first attempt should be deemed acceptable.

Randomized study assessing the accuracy of cervical facet joint nerve (medial branch) blocks using different injectate volumes.

BACKGROUND: Neck pain is a frequent cause of disability, with facet joint arthropathy accounting for a large percentage of cases. The diagnosis of cervical facet joint pain is usually made with diagnostic blocks of the nerves that innervate them. Yet, medial branch blocks are associated with a high false-positive rate. One hypothesized cause of inaccurate diagnostic blocks is inadvertent extravasation of injectate into adjacent pain-generating structures. The objective of this study was to evaluate the accuracy of medial branch blocks by using different injectate volumes. METHODS: Twenty-four patients received cervical medial branch blocks, using either 0.5 or 0.25 ml of bupivacaine mixed with contrast. One half of the patients in each group were suballocated to receive the blocks in the prone position and the other half through a lateral approach. Participants then underwent computed tomography of the cervical spine to evaluate accuracy and patterns of aberrant contrast spread. RESULTS: Sixteen instances of aberrant spread were observed in nine patients receiving blocks using 0.5 ml versus seven occurrences in six patients in the 0.25 ml group (P = 0.07). Aberrant spread was most commonly observed (57%) when an injection at C3 engulfed the third occipital nerve. Among the 86 nerve blocks, foraminal spread occurred in five instances using 0.5 ml and in two cases with 0.25 ml. The six "missed" nerves were equally divided between treatment groups. No significant difference in any outcome measure was observed between the prone and lateral positions. CONCLUSIONS: Reducing the volume during cervical medial branch blocks may improve precision and accuracy.

Multicenter, randomized, comparative cost-effectiveness study comparing 0, 1, and 2 diagnostic medial branch (facet joint nerve) block treatment paradigms before lumbar facet radiofrequency denervation.

BACKGROUND: Among patients presenting with axial low back pain, facet arthropathy accounts for approximately 10-15% of cases. Facet interventions are the second most frequently performed procedures in pain clinics across the United States. Currently, there are no uniformly accepted criteria regarding how best to select patients for radiofrequency denervation. METHODS: A randomized, multicenter study was performed in 151 subjects with suspected lumbar facetogenic pain comparing three treatment paradigms. Group 0 received radiofrequency denervation based solely on clinical findings; group 1 underwent denervation contingent on a positive response to a single diagnostic block; and group 2 proceeded to denervation only if they obtained a positive response to comparative blocks done with lidocaine and bupivacaine. A positive outcome was predesignated as > or =50% pain relief coupled with a positive global perceived effect persisting for 3 months. RESULTS: In group 0, 17 patients (33%) obtained a successful outcome at 3 months versus eight patients (16%) in group 1 and 11 (22%) patients in group 2. Denervation success rates in groups 0, 1, and 2 were 33, 39, and 64%, respectively. Pain scores and functional capacity were significantly lower at 3 months but not at 1 month in group 2 subjects who proceeded to denervation compared with patients in groups 0 and 1. The costs per successful treatment in groups 0, 1, and 2 were $6,286, $17,142, and $15,241, respectively. CONCLUSIONS: Using current reimbursement scales, these findings suggest that proceeding to radiofrequency denervation without a diagnostic block is the most cost-effective treatment paradigm.

Randomized, double-blind, placebo-controlled, dose-response, and preclinical safety study of transforaminal epidural etanercept for the treatment of sciatica.

BACKGROUND: Recent evidence implicates the inflammatory cytokine tumor necrosis factor as a major cause of radiculopathy. Yet, whereas open-label studies with systemically delivered tumor necrosis factor inhibitors have yielded positive results, a placebo-controlled study failed to demonstrate efficacy. One variable that may have contributed to poor outcomes is low drug levels at the site of nerve inflammation. To date, no studies have evaluated the efficacy or safety of epidurally administered anti-tumor necrosis factor agents. METHODS: A double-blind, placebo-controlled, dose-response study was conducted to evaluate an epidural tumor necrosis factor inhibitor. Twenty-four patients with subacute lumbosacral radiculopathy were randomly assigned to receive two transforaminal epidural injections of 2, 4, or 6 mg of entanercept 2 weeks apart in successive groups of eight. In each group, two patients received epidural saline. A parallel epidural canine safety study was conducted using the same injection doses and paradigm as in the clinical study. RESULTS: The animal and human safety studies revealed no behavioral, neurologic, or histologic evidence of drug-related toxicity. In the clinical arm, significant improvements in leg and back pain were collectively noted for the etanercept-treated patients, but not for the saline group, one month after treatment. One patient in the saline group (17%), six patients in the 2-mg group (100%), and four patients each in the 4-mg and 6-mg groups (67%) reported at least 50% reduction in leg pain and a positive global perceived effect one month after treatment. Six months after treatment, the beneficial effects persisted in all but one patient. CONCLUSION: Epidural entanercept holds promise as a treatment for lumbosacral radiculopathy.

Prognostic value of hypersensitivity reactions on epidural steroid injection outcomes: a phenotypic signature? A prospective cohort study.

BACKGROUND: Studies have found that diffuse pain, indicative of central sensitization, portends poor interventional outcomes. Multiple chemical sensitivities are associated with signs of central sensitization. We sought to prospectively determine whether hypersensitivity reactions (HR) were associated with epidural steroid injection (ESI) outcomes. METHODS: HR were classified as immune-related or non-immune-related and categorized by number (0=low, 1 or 2=intermediate, ≥3=high). The primary outcome measure was mean reduction in average leg pain score 1 month post-procedure. A positive outcome was defined as a two-point or greater decrease in average leg pain accompanied by satisfaction 1 month post-procedure. RESULTS: The mean number of immune-mediated and non-immune-mediated HR were 0.6±1.2 and 0.8±1.4, respectively. Individuals in the high (n=24) total HR group had a mean reduction in average leg pain of 0.1±2.7, compared with those in the low (n=61; 1.8±2.1, p=0.025) and intermediate groups (n=52; 1.6±3.1, p=0.060). For back pain and categorical successful outcome, those with fewer HR experienced greater benefit. There were no differences in outcomes when patients were stratified by immune-related HR. Among participants in the low, intermediate and high non-immune-mediated HR groups, the mean reductions in average leg pain scores were 1.7±2.5, 1.6±3.0, and -0.2±2.3, respectively (p = 0.002). 51%, 35%, and 12% of people with low, intermediate and high numbers of non-immune-mediated HR experienced a positive categorical outcome, respectively (p=0.007). CONCLUSIONS: Non-immune-related HR were inversely correlated with some ESI outcome measures.

Fluoroscopically Guided vs Landmark-Guided Sacroiliac Joint Injections: A Randomized Controlled Study.

OBJECTIVES: To determine the prevalence of intra- and extra-articular sacroiliac joint (SIJ) pain, which injection is more beneficial, and whether fluoroscopy improves outcomes. PATIENTS AND METHODS: This patient- and evaluator-blinded comparative effectiveness study randomized 125 participants with SIJ pain from April 30, 2014, through December 12, 2017, to receive fluoroscopically guided injections into the joint capsule (group 1) or "blind" injections to the point of maximum tenderness using sham radiographs (group 2). The primary outcome was average pain on a 0 to 10 scale 1 month after injection. A positive outcome was defined as at least a 2-point decrease in average pain score coupled with positive (>3) satisfaction on a Likert scale from 1 to 5. RESULTS: For the primary outcome, no significant differences were observed between groups (mean ± SD change from baseline, -2.3±2.4 points in group 1 vs -1.7±2.3 points in group 2; 95% CI, -0.33 to 1.36 points for adjusted difference; P=.23), nor was there a difference in the proportions of positive blocks (61% vs 62%) or 1-month categorical outcome (48% vs 40% in groups 1 and 2, respectively; P=.33). At 3 months, the mean ± SD reductions in average pain (-1.8±2.1 vs -0.9 ± 2.0 points; 95% CI, 0.11 to 1.58 points for adjusted difference; P=.02) and worst pain (-2.2±2.5 vs -1.4±2.0 points; 95% CI, 0.01 to 1.66 points for adjusted difference; P=.049) were greater in group 1 than 2, with other outcome differences falling shy of statistical significance. CONCLUSION: Although fluoroscopically guided injections provide greater intermediate-term benefit in some patients, these differences are modest and accompanied by large cost differences. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT02096653.

Randomized placebo-controlled study evaluating lateral branch radiofrequency denervation for sacroiliac joint pain.

BACKGROUND: Sacroiliac joint pain is a challenging condition accounting for approximately 20% of cases of chronic low back pain. Currently, there are no effective long-term treatment options for sacroiliac joint pain. METHODS: A randomized placebo-controlled study was conducted in 28 patients with injection-diagnosed sacroiliac joint pain. Fourteen patients received L4-L5 primary dorsal rami and S1-S3 lateral branch radiofrequency denervation using cooling-probe technology after a local anesthetic block, and 14 patients received the local anesthetic block followed by placebo denervation. Patients who did not respond to placebo injections crossed over and were treated with radiofrequency denervation using conventional technology. RESULTS: One, 3, and 6 months after the procedure, 11 (79%), 9 (64%), and 8 (57%) radiofrequency-treated patients experienced pain relief of 50% or greater and significant functional improvement. In contrast, only 2 patients (14%) in the placebo group experienced significant improvement at their 1-month follow-up, and none experienced benefit 3 months after the procedure. In the crossover group (n = 11), 7 (64%), 6 (55%), and 4 (36%) experienced improvement 1, 3, and 6 months after the procedure. One year after treatment, only 2 patients (14%) in the treatment group continued to demonstrate persistent pain relief. CONCLUSIONS: These results provide preliminary evidence that L4 and L5 primary dorsal rami and S1-S3 lateral branch radiofrequency denervation may provide intermediate-term pain relief and functional benefit in selected patients with suspected sacroiliac joint pain. Larger studies are needed to confirm these results and to determine the optimal candidates and treatment parameters for this poorly understood disorder.

Acupuncture for the Treatment of Chronic Pain in the Military Population: Factors Associated With Treatment Outcomes.

OBJECTIVES: Acupuncture is characterized as an alternative or complementary medicine with a low complication rate and minimal side effects. There is a lack of robust evidence that shows acupuncture is an effective treatment for chronic pain. The purpose of this study was to determine which (if any) characteristics can predict successful response to acupuncture in chronic pain patients treated at military treatment facilities. METHODS: Data from 222 patients who received treatment for a chronic pain condition were collected from 2 medical centers. The patients underwent at least 4 acupuncture treatments and had an average pain score of 4 or higher on a 0- to 10-point numerical rating scale or visual analog scale in the week before treatment initiation. A successful outcome was defined to be a 2-point or greater reduction on the numerical rating scale or visual analog scale 12 weeks postinitial treatment. RESULTS: The overall treatment success rate was 42.3%. Multivariate logistic regression found a higher baseline pain rating and the use of stimulation needles to be associated with a positive outcome (odds ratio [OR]=1.26; 95% confidence interval [CI], 1.03-1.55; P=0.02 and OR=2.73; 95% CI, 1.39-5.32; P=0.03, respectively). Only the presence of one or more psychological comorbidities was found to be associated with treatment failure (OR=0.67; 95% CI, 0.49-0.92; P=0.01). DISCUSSION: The use of electrical stimulation and higher baseline pain score were associated with a positive treatment outcome, while the presence of a psychological comorbidity diminished the likelihood of treatment success. Practitioners should consider using electrical stimulation more frequently, and addressing psychopathology before or concurrent to treatment, when initiating acupuncture.