Epidural Injections for Spinal Pain: A Systematic Review and Meta-analysis Evaluating the “Control” Injections in Randomized Controlled Trials
Bicket, Mark C. M.D.*; Gupta, Anita D.O.†; Brown, Charlie H. IV M.D.‡; Cohen, Steven P. M.D.§
Background: Epidural steroid injection is the most frequently performed pain procedure. This study of epidural steroid “control” injections aimed to determine whether epidural nonsteroid injections constitute a treatment or true placebo in comparison with nonepidural injections for back and neck pain treatment.
Methods: This systematic review with direct and indirect meta-analyses used PubMed and EMBASE searches from inception through October 2012 without language restrictions. Study selection included randomized controlled trials with a treatment group receiving epidural injections of corticosteroids or another analgesic and study control groups receiving either an epidural injection devoid of treatment drug or a nonepidural injection. Two reviewers independently extracted data including short-term (up to 12 weeks) pain scores and pain outcomes. All reviewers evaluated studies for eligibility and quality.
Results: A total of 3,641 patients from 43 studies were included in this systematic review and meta-analysis. Indirect comparisons suggested epidural nonsteroid were more likely than nonepidural injections to achieve positive outcomes (risk ratio, 2.17; 95% CI, 1.87–2.53) and provide greater pain score reduction (mean difference, −0.15; 95% CI, −0.55 to 0.25). In the very limited direct comparisons, no significant differences were noted between epidural nonsteroid and nonepidural injections for either outcome (risk ratio [95% CI], 1.05 [0.88–1.25]; mean difference [95% CI], 0.22 [−0.50 to 0.94]).
Conclusion: Epidural nonsteroid injections may provide improved benefit compared with nonepidural injections on some measures, though few, low-quality studies directly compared controlled treatments, and only short-term outcomes (≤12 weeks) were examined.
What We Already Know about This Topic
* Epidural nonsteroid injections (primarily local anesthetics) may provide treatment for neuropathic pain via several potential mechanisms
What This Article Tells Us That Is New
* This systematic review of the literature found that the few available trials directly comparing epidural nonsteroid with nonepidural injections showed no benefit
* Indirect comparisons of the techniques from a larger number of trials suggested epidural nonsteroid injections may confer some benefit
SPINAL pain is a leading cause of disability in the industrialized world. The lifetime prevalence for low back pain ranges between 50 and 80%1
; for neck pain, the estimates are between 50 and 67%.2
Compounding the high disease burden is the absence of any reliably effective treatment.
More than one third of back pain cases can be classified as predominantly “neuropathic.”4
The distinction between nociceptive and neuropathic spinal pain has significant treatment implications in that the latter may be more amenable to therapy. A cornerstone of conservative treatment for radiculopathy is epidural steroid injections (ESI), which have been used for more than 50 yr.5
In the United States, ESI are the most commonly performed intervention for pain.6
Despite their frequent use, the question of whether ESI afford long-term benefit is mired in controversy. Recent reviews demonstrate a glaring lack of consensus. Most experts concede that ESI provide at least short-term palliation in well-selected patients, but the results are divided as to whether they confer long-term benefit.7–26
In one review that evaluated the effect physician specialty has on conclusions regarding efficacy, 15 of 23 systematic or evidence-based review articles concluded that ESI are effective, with those reviews performed by interventionalists being approximately three times more likely to be positive compared with reviews conducted by noninterventionalist physicians.27
Challenges in evaluating ESI studies include disparities in selection criteria, injection parameters, and criteria for success. It is generally acknowledged that patients with shorter duration of symptoms, radicular symptomatology, lesser disease burden, and the absence of coexisting psychosocial pathology, fare better with therapeutic interventions.9
But what is not commonly appreciated is the impact the “control” injection has on outcomes.
Two main types of “control” injections are used in ESI randomized controlled trials (RCTs): epidural saline or local anesthetic [epidural nonsteroid injection (ENSI)]; and intramuscular or ligamentous injections (nonepidural). In evaluating the literature, most experts fail to discern the differences, considering them as “equivalent placebos.” However, the potential benefit of corticosteroids for a chronic condition devoid of an inflammatory component is minimal. In addition, recent studies suggest that radiculopathy may also result from chemical irritation of nerve roots due to inflammatory cytokines released from herniated discs.32
Hence, ENSI may provide significant pain relief by several mechanisms: diluting inflammatory cytokines; lysing scar tissue; enhancing blood flow to ischemic nerve roots34
; suppressing ectopic discharges from injured nerves35
; and “unwinding” central sensitization. However, few investigators have entertained this possibility.9
If ENSI provide benefit, then the proportion of controlled studies evaluating ESI in which the results are positive should be less when the control group received ENSI than for nonepidural injections, because the former constitutes a comparative-effectiveness study. The purpose of this study is to examine whether epidural injections of noncorticosteroid mixtures constitute a treatment or true placebo in patients with spinal pain. This was done by comparing between-group differences for pain outcomes from RCTs in which the “control” injectate was administered epidurally (ENSI), with those in which it was injected into the soft tissue (nonepidural injection).
Materials and Methods
Data Sources and Searches
This quantitative systematic review and meta-analysis followed recent methodological guidelines.38
A search of PubMed and EMBASE databases using the terms “epidural steroid,” “epidural injection,” “caudal,” “segmental nerve block,” “nerve root block,” and “transforaminal injection” was performed without publication date or language restriction in April 2009, and repeated in October 2012. Besides online language tools, in-person translation services were provided through the Johns Hopkins Hospital international services translation program. Search limitations included RCTs and adults older than 18 yr of age. Additional studies were identified through hand searches of ESI review reference lists. Figure 1
and table 1
show further details of the search strategy. Among 690 potentially eligible studies, 244 duplicate references were excluded leaving 446 studies for evaluation, with another 356 deemed ineligible after initial abstract screening. This left 90 articles for final review.
All authors performed study selection by consensus. Eligible studies included only RCTs with: (1) patients with back or neck pain with or without radiculopathy; (2) a treatment group receiving epidural injections of corticosteroids or another analgesic; (3) a control group receiving either an epidural injection devoid of treatment drug or a nonepidural injection; and (4) short-term outcome data up to 12 weeks after the initial injection (if the injection scheme was open-ended) or after the final injection in an injection series. On the basis of these criteria, 47 studies were further excluded. The remaining 43 studies comprised the systematic review. For inclusion in the meta-analysis, studies had to present numeric pain data including SD.
Data extraction was performed independently by two authors (Drs. Bicket and Gupta), and included patient characteristics, control and treatment injections, rating scores for pain, pain symptoms, and disability scores. Variables including number and percentage of patients, and mean with SD, were extracted, calculated from primary data, or estimated from figures. When not given, SD was calculated using standard errors (SE) and 95% CI.
Quality and Risk of Bias Assessment
Study risk of bias was assessed using a Cochrane risk of bias tool‖
and secondarily using Jadad40
methodological quality scale, whereas an ESI technical quality scale evaluated stringency of selection criteria (table 2
). The ESI technical quality scale was developed by the investigators after a review of clinical studies evaluating factors associated with treatment outcomes for ESI and back pain in general.29
The questions chosen were designed to identify those factors most likely to be associated with treatment response, and to address relevant methodological concerns not reflected in the methodological assessments (e.g.
, avoidance of cointerventions). This scale was then reviewed with slight modifications by two disinterested Pain Medicine Program Directors at nonstudy institutions, underwent test–retest reliability assessments (>95%) by three study investigators, and is consistent with other rating scales used to evaluate technical quality and clinical relevance for procedural interventions.61
Although its design suggests possible face, content, and construct validity,62–64
the scale was not formally validated in a clinical trial. All bias and technical ratings were performed by two of three authors independently (Drs. Brown, Gupta, and Bicket). In the event of disparate ratings, a third author (Dr. Cohen) adjudicated the results. Low methodological quality studies had at least one high likelihood of bias Cochrane risk domain or fulfilled less than three Jadad criteria, whereas low technical quality studies scored less than 4 points on the ESI technical quality scale.
Categorical pain ratings were transformed into a dichotomous “positive response” variable, with “positive response,” “success,” “relief of pain,” and “50% or more reduction in pain” representing positive responses. Visual and numerical pain ratings were transformed into a continuous 0–10 rating scale and, when presented, analyzed by body site (global, leg, back). When global pain ratings were not available for aggregate analysis, leg pain ratings were used in their place.37
Baseline and comparison data were the most recent data points available before and after the first injection (or injection series), respectively. All comparison data were observed within 12 weeks of the initial injection (if the injection scheme was open-ended) or after the final injection in the first injection series. Data on intramuscular steroids and intramuscular saline/local anesthetic were combined as a comparison group for nonepidural injections, a decision consistent with RCTs and systematic reviews demonstrating a lack of efficacy of parenteral steroids for sciatica.70
The principal summary measures were positive response (dichotomous) and pain score reduction on an 11-point rating scale (continuous). Effect size of dichotomous data was calculated as relative risk (RR), which represents the risk of a positive response for pain relief in the ESI treatment group divided by risk of a positive response in the control group. Effect size of continuous data was calculated as mean difference (MD), which represents the difference in pain score reduction between the two groups.
Random effects models were examined. Heterogeneity was measured by I2
which assessed variability among studies not attributable to chance alone. Significant heterogeneity was present with I2
values of more than 50%. To assess for small study effects and possible publication bias, a funnel plot was analyzed when more than 10 studies were present. Indirect comparisons of aggregate data were performed by calculating differences in pertinent treatment outcomes using the formulas log(RRAB
) − log(RRAC
) = log(RRBC
; and SEAB2
Quality analysis was performed excluding each group of low-quality studies for both methodological and technical scores, and body site analysis was performed by substituting back pain for leg pain data. Calculations were done using Microsoft Excel 2011 (Microsoft Corp., Redmond, WA), RevMan Version 5.1.7. (The Cochrane Collaboration, The Nordic Cochrane Centre, Copenhagen, Denmark, 2011), and Stata 12 (StataCorp LP, College Station, TX). Statistical significance for all tests was set at a P
value of 0.05 or less.
In the systematic review, 43 studies provided data for ESI treatment and control groups representing 3,641 patients37
). Table 3
summarizes study design, patient population, injection groups, outcome measures, and results. Sample sizes ranged from 22 to 228 patients. Injections varied by location, route, frequency, volume, and steroid and local anesthetic content. The number of injections was one in 9 studies, two in 5 studies, three in 4 studies, and a variable number in the remaining 25 studies. Five studies reported on cervical injections, 25 studies on lumbar injections, and 13 on caudal injections. Twenty-eight studies were of both high methodological and technical quality (fig. 3
and table 4
Three studies directly compared epidural nonsteroid with nonepidural injections.67
Both injections were examined in one study of high methodological and technical quality with 130 patients using four “control” groups. In this study81
the proportion of patients with 50% or more pain relief was not significantly different among all comparison groups: 7% for transforaminal local anesthetic, 19% for transforaminal saline, 21% for intramuscular steroids, and 13% for intramuscular saline. No difference in pain score reduction was found among the four groups. Two other studies were of high technical quality and low methodological quality. In a study by Iversen et al.67
evaluating 116 patients using two “control” groups, there was no significant difference in pain score reduction between epidural and intramuscular saline. In an earlier study by Klenerman et al.83
using three “control” groups in 63 patients, neither reduction in pain scores nor positive response as judged by a physician (sham nonepidural dry needling 83%, epidural local anesthetic 69%, and epidural saline 69%) significantly differed among treatments. Of note, none of these three studies were designed to detect a difference between two “control” groups, and the latter two studies67
used excessively high injectate volumes (≥20 ml) that diluted the steroid dose, resulting in no differences being observed between the steroid and any control group.
Among studies included in the systematic review, 22.9% (8 of 35) of studies comparing ESI with ENSIs demonstrated benefit for the treatment, which was less than the 58.3% (7 of 12) reporting a positive effect when nonepidural injections were used as the control. When low-quality studies were excluded, these numbers changed only slightly, to 27.3% (6 of 22) and 50.0% (2 of 4), respectively.
For the positive response outcome, 166 patients from two studies provided data for the direct meta-analysis of ENSIs and nonepidural injections (fig. 4
). For the indirect meta-analysis, 1,512 patients from 23 studies provided data comparing ESI versus
ENSIs and 663 patients from seven studies provided data comparing ESI versus
nonepidural injections. The indirect meta-analysis revealed a greater than two-fold increased likelihood for a positive response to ENSI, compared with nonepidural injection (RR [95% CI], 2.17 [1.87–2.53]). Differences between epidural nonsteroid and nonepidural injections for the direct meta-analysis were not significant (RR [95% CI], 0.90 [0.60–1.33]). Table 5
presents other effect estimates for positive response. The absolute benefit favoring epidural nonsteroid over nonepidural injections is actually greater (risk difference [95% CI], 0.27 [0.15–0.39]) than the difference between ESI and epidural nonsteroid (0.04 [−0.01 to 0.10]). Heterogeneity was 0% for the direct comparison and 31–33% for the two groups used in indirect comparisons. When studies of low methodological or technical quality were excluded, no significant changes in outcomes or heterogeneity were noted for any comparisons involving a positive response, which is consistent with previous reviews.54
Pain Score Reduction
For the pain score reduction outcome, 201 patients from two studies provided data for the direct meta-analysis (fig. 5
). For the indirect meta-analysis, 1,936 patients from 22 studies provided data comparing ESI versus
ENSIs and 619 patients in four studies provided data comparing ESI versus
nonepidural injections. Differences between epidural nonsteroid and nonepidural injections were nonsignificant in the direct meta-analysis (MD [95% CI], 0.22 [−0.50 to 0.94]). For the indirect meta-analysis, a small, nonsignificant difference favoring ENSIs over nonepidural injections was noted (MD [95% CI], −0.15 [−0.55 to 0.25]). Heterogeneity was 0% for the direct comparison and 60–72% for the two groups used in indirect comparisons. When studies of low methodological or technical quality were excluded, no significant changes in outcome or heterogeneity were noted for all comparisons involving pain score reduction.
Estimates of both positive response and pain score reduction did not change significantly with either exclusion of low technical and methodological studies or substitution of back pain scores for leg pain scores for the seven studies stratifying pain by body site. The only comparison group with 10 or more studies was the ESI versus epidural nonsteroid comparison. Examination of funnel plots for studies comparing ESI and ENSIs for both primary outcomes revealed small study effects for only the pain score reduction outcome. The Egger test confirmed the presence of possible publication bias (P < 0.001). Post hoc sensitivity analysis to identify and correct for funnel plot asymmetry arising from publication bias included the “trim and fill” method. This method estimated eight studies were needed to account for possible publication bias, and provided a corrected pain score reduction estimate that was not significant.
The findings in this systematic review and meta-analysis comparing epidural nonsteroid and nonepidural injections are mixed, with only one study of high quality directly comparing these treatments. Although no difference in direct outcomes between the two “control” injections was demonstrated, the larger number of studies providing indirect comparisons suggests ENSIs may provide greater benefit for spinal pain than nonepidural injections. This conclusion is based on the significant but small difference found between the two treatments when examining the positive response outcome. For this outcome, the benefit favoring epidural nonsteroid over nonepidural injections is actually greater (risk difference [95% CI], 0.27 [0.15–0.39]) than the difference between ESI and epidural nonsteroid, suggesting that, at least in the short term, most of the benefit of epidural injections may derive from the solution itself, rather than the steroid. ENSIs also showed a nonsignificant trend toward greater relief when examining pain score reduction with indirect comparisons. A single binary outcome measure may represent a better reflection of global perceived effect than reduction in pain score, which is only one of many core domain outcome measures,109
and in most studies analyzed signified only the pain rating at a single cross-section in time.
Although several review articles9
and clinical trials67
have alluded to the possibility of a therapeutic effect for epidural nonsteroid solutions, this assertion has never been systematically examined. In addition to the evidence presented here, several other randomized studies indirectly bolster this assertion. Randomized, double-blind studies comparing high doses of steroid with lower doses in which the steroid was replaced by saline110
or local anesthestic112
have consistently failed to demonstrate any significant differences between treatment groups. A systematic review by Rabinovitch et al.113
found a statistically significant benefit for larger epidural injectate volumes irrespective of the contents, suggesting that the beneficial effect of nonsteroid solutions may counterbalance dilution of steroids.
There are several possible explanations for our findings. The most likely is that nonsteroid solutions injected epidurally may provide benefit comparable with that of steroids via
a host of different mechanisms, to include the suppression of ectopic discharges from inflamed nerves, enhancing blood flow to ischemic nerve roots, lysis of iatrogenic and inflammatory adhesions, the washout of proinflammatory cytokines, and reversing peripheral and central sensitization.9
A second possible reason involves the placebo effect. Epidural injections, especially those administered via
the transforaminal approach, often elicit a reproduction of radicular symptoms,114,115
which is not observed with soft-tissue injections, and may undermine the effectiveness of blinding. When this occurs, it may lead to a greater placebo response with ENSIs, as patients mistakenly believe they received epidural steroids.116
The implications of these findings are widespread and protean. Investigators designing clinical trials, and specialty organizations, patient advocate groups, and third-party payers evaluating studies, should consider these results when evaluating the efficacy of ESI. Specifically, trials that include an epidural nonsteroid “placebo” group may be less likely to demonstrate a difference in pain outcomes compared with nonepidural injections. In high-risk patients (e.g.
, patients with previous surgery) and procedures (e.g.
, cervical and thoracic transforaminal ESI) in which the inadvertent intravascular injection of depo-steroids can have catastrophic consequences such as paralysis and death,117–119
physicians might consider removing steroids from the injectate and using nonsteroid solutions as a first-line treatment. Using nonsteroid solutions may also reduce the risk of rare but potentially fatal complications such as meningitis, which has recently been attributed to a contaminated steroid batch.#
On the basis of these results and the results of other clinical trials demonstrating no differences between high- and low-dose ESI110–112
the dose of steroids may be considerably reduced or even eliminated in high-risk patient populations. Examples of these patients might include individuals at high risk for avascular necrosis,121
and those with diabetes,122
at high risk for infection,123
poor wound healing, or in whom the temporary suppression of the adrenocortical axis could adversely affect outcomes (e.g.
, those scheduled for major surgery).124
These results should be interpreted in the context of some limitations. First, direct comparisons of the different types of controlled injections were only present in a limited number of low-quality randomized clinical trials. Although no standard guidelines exist regarding the minimum number of studies needed to perform a meta-analysis, analyses of limited trials do exist125
and generally agree with longer-term results.126
Indirect comparisons do not qualify at the same level of evidence as randomized comparisons, because they represent mere observations of trials, may be subject to bias, and may inaccurately estimate treatment effect.127
Yet, none of the three studies that directly compared the different types of “control” injections were designed or powered to detect a difference between nonsteroid groups (which would require significantly more patients than a study designed to detect a difference between ESI and a true placebo),67
and two used excessively high injection volumes that resulted in a failure to detect a difference between the diluted steroid treatment (ESI) and any control group.67
As the authors of the most robust study noted,81
detecting a difference between two treatments (or control groups) with similar effect sizes would require between 1,000 and 2,000 patients, which is not practical. Consequently, indirect analyses evaluating numerous, well-designed studies may provide a better likelihood of detecting a difference between nonepidural injections and ENSIs in this context. Second, some analyses exhibited substantial heterogeneity, which is likely attributable to differences in methods or outcome assessments. Although the conversion of different pain-rating scales may result in increased heterogeneity and greater difficulty in detecting differences in outcomes, previous studies have consistently determined that there is a high correlation between pain-rating scales,128–130
and scores derived from different scales are often combined in meta-analyses, including those evaluating ESI.131
With regard to differences in treatment parameters (e.g.
, region, number of injections, dose and type of steroid), recent reviews have concluded that minor variations in practice are likely to have no significant effect on outcome.27
For example, increasing the depo-steroid dose of more than 40 mg appears to provide no added benefit, and there is little evidence that a series of ESI results in better outcomes than a single injection, or tailoring the number of injections to patient response.27
However, the conglomeration of these different factors (e.g.
, injection type and number, dose, volume) may have a cumulative effect, and hence limit the generalization of the meta-analyses. Third, publication bias may be present for studies that compared ESI and ENSIs, with modeling suggesting a nonsignificant outcome favoring ESI when a correction for small study effects was performed. Fourth, our technical rating scale remains formally unvalidated. If detecting a difference between a placebo and control requires between 50 and 150 patients, identifying outcome difference for different variables (e.g.
, fluoroscopy vs.
no fluoroscopy, disability vs.
no disability) would require exponentially more patients, and be logistically challenging. Fifth, inherent to any meta-analysis are the biases contained in the included studies. Finally, to enhance generalization, we elected to include studies with follow-up periods varying from a few days to up to 3 months. Hence, this efficacy analysis was not designed to assess the long-term benefits of ESI or controlled injections.
In conclusion, the evidence comparing epidural nonsteroid with nonepidural injections is limited but suggests that ENSIs may not constitute a true placebo treatment. In light of these findings, opportunities exist for clinicians and investigators to modify their approach to these procedures, such as reducing110–112
or even in some cases eliminating, the steroid component of epidural injections in high-risk scenarios, and performing high-quality RCTs that directly compare epidural nonsteroid and nonepidural injections.
# Centers for Disease Control and Prevention. Meningitis and Stroke Associated with Potentially Contaminated Product. Atlanta, GA: Centers for Disease Control and Prevention, 2012. Available at: http://emergency.cdc.gov/HAN/han00327.asp
. Accessed April 23, 2013. Cited Here...
‖ Higgins JPT, Altman DG, Sterne JAC: Assessing risk of bias in included studies, Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 (updated March 2011). Edited by Higgins JPT, Green S. The Cochrane Collaboration, 2011. Available at: www.cochrane-handbook.org
. Accessed June 3, 2013. Cited Here...
1. Cohen SP, Argoff CE, Carragee EJ. Management of low back pain. BMJ. 2008;337:a2718
2. Rubin DI. Epidemiology and risk factors for spine pain. Neurol Clin. 2007;25:353–71
3. Hogg-Johnson S, van der Velde G, Carroll LJ, Holm LW, Cassidy JD, Guzman J, Côté P, Haldeman S, Ammendolia C, Carragee E, Hurwitz E, Nordin M, Peloso P. The burden and determinants of neck pain in the general population: Results of the Bone and Joint Decade 2000–2010 Task Force on Neck Pain and Its Associated Disorders. Spine. 2008;33(4 suppl):S39–51
4. Freynhagen R, Baron R, Gockel U, Tölle TR. painDETECT: A new screening questionnaire to identify neuropathic components in patients with back pain. Curr Med Res Opin. 2006;22:1911–20
5. Lievre JA, Bloch-Michel H, Pean G. L’ hydrocortisone en injection locale. Revue du Rhumatisme et des Maladies Osteo-articulares 1953;20:310–1
6. Manchikanti L, Pampati V, Falco FJ, Hirsch JA. Growth of spinal interventional pain management techniques: Analysis of utilization trends and Medicare expenditures 2000 to 2008. Spine (Phila Pa 1976). 2013;38:157–68
7. Eckel TS, Bartynski WS. Epidural steroid injections and selective nerve root blocks. Tech Vasc Interv Radiol. 2009;12:11–1
8. American College of Occupational and Environmental Medicine (ACOEM). Low Back Disorders, Occupational Medicine Practice Guidelines: Evaluation and Management of Common Health Problems and Functional Recovery of Workers. 20072nd edition Beverly Farms OEM Press
9. Roberts ST, Willick SE, Rho ME, Rittenberg JD. Efficacy of lumbosacral transforaminal epidural steroid injections: A systematic review. PM R. 2009;1:657–68
10. Manchikanti L, Boswell MV, Datta S, Fellows B, Abdi S, Singh V, Benyamin RM, Falco FJ, Helm S, Hayek SM, Smith HSASIPP. . Comprehensive review of therapeutic interventions in managing chronic spinal pain. Pain Physician. 2009;12:E123–98
11. Chou R, Atlas SJ, Stanos SP, Rosenquist RW. Nonsurgical interventional therapies for low back pain: A review of the evidence for an American Pain Society clinical practice guideline. Spine (Phila Pa 1976). 2009;34:1078–93
12. Diwan S, Manchikanti L, Benyamin RM, Bryce DA, Geffert S, Hameed H, Sharma ML, Abdi S, Falco FJ. Effectiveness of cervical epidural injections in the management of chronic neck and upper extremity pain. Pain Physician. 2012;15:E405–34
13. Conn A, Buenaventura RM, Datta S, Abdi S, Diwan S. Systematic review of caudal epidural injections in the management of chronic low back pain. Pain Physician. 2009;12:109–35
14. Staal JB, de Bie RA, de Vet HC, Hildebrandt J, Nelemans P. Injection therapy for subacute and chronic low back pain: An updated Cochrane review. Spine (Phila Pa 1976). 2009;34:49–9
15. Karnezis IA. Minimally invasive therapeutic interventional procedures in the spine: An evidence-based review. Surg Technol Int. 2008;17:259–68
16. Benyamin RM, Manchikanti L, Parr AT, Diwan S, Singh V, Falco FJ, Datta S, Abdi S, Hirsch JA. The effectiveness of lumbar interlaminar epidural injections in managing chronic low back and lower extremity pain. Pain Physician. 2012;15:E363–404
17. Carragee EJ, Hurwitz EL, Cheng I, Carroll LJ, Nordin M, Guzman J, Peloso P, Holm LW, Côté P, Hogg-Johnson S, van der Velde G, Cassidy JD, Haldeman S. Treatment of neck pain: Injections and surgical interventions: Results of the Bone and Joint Decade 2000–2010 Task Force on Neck Pain and Its Associated Disorders. Spine. 2008;33(4S):S153–69
18. DePalma MJ, Slipman CW. Evidence-informed management of chronic low back pain with epidural steroid injections. Spine J. 2008;8:45–5
19. Legrand E, Bouvard B, Audran M, Fournier D, Valat JPSpine Section of the French Society for Rheumatology. . Sciatica from disk herniation: Medical treatment or surgery? Joint Bone Spine. 2007;74:530–5
20. Stafford MA, Peng P, Hill DA. Sciatica: A review of history, epidemiology, pathogenesis, and the role of epidural steroid injection in management. Br J Anaesth. 2007;99:461–73
21. Peloso P, Gross A, Haines T, Trinh K, Goldsmith CH, Burnie S. Cervical Overview Group: Medicinal and injection therapies for mechanical neck disorders. Cochrane Database Syst Rev. 2007;3:CD000319
22. Young IA, Hyman GS, Packia-Raj LN, Cole AJ. The use of lumbar epidural/transforaminal steroids for managing spinal disease. J Am Acad Orthop Surg. 2007;15:228–38
23. Irwin RW, Zuhosky JP, Sullivan WJ, Panagos A, Foye PM, Sable AW. Industrial medicine and acute musculoskeletal rehabilitation. 4. Interventional procedures for work-related cervical spine conditions. Arch Phys Med Rehabil. 2007;88(3 suppl 1):S18–21
24. Parr AT, Manchikanti L, Hameed H, Conn A, Manchikanti KN, Benyamin RM, Diwan S, Singh V, Abdi S. Caudal epidural injections in the management of chronic low back pain: A systematic appraisal of the literature. Pain Physician. 2012;15:E159–98
25. Quraishi NA. Transforaminal injection of corticosteroids for lumbar radiculopathy: Systematic review and meta-analysis. Eur Spine J. 2012;21:214–9
26. Benoist M, Boulu P, Hayem G. Epidural steroid injections in the management of low-back pain with radiculopathy: An update of their efficacy and safety. Eur Spine J. 2012;21:204–13
27. Cohen SP, Bicket MC, Jamison D, Wilkinson I, Rathmell JP. Epidural steroids: A comprehensive, evidence-based review. Reg Anesth Pain Med. 2013;38:175–200
28. Airaksinen O, Brox JI, Cedraschi C, Hildebrandt J, Klaber-Moffett J, Kovacs F, Mannion AF, Reis S, Staal JB, Ursin H, Zanoli GCOST B13 Working Group on Guidelines for Chronic Low Back Pain. . Chapter 4. European guidelines for the management of chronic nonspecific low back pain. Eur Spine J. 2006;15(suppl 2):S192–300
29. Hopwood MB, Abram SE. Factors associated with failure of lumbar epidural steroids. Reg Anesth. 1993;18:238–43
30. Jamison RN, VadeBoncouer T, Ferrante FM. Low back pain patients unresponsive to an epidural steroid injection: Identifying predictive factors. Clin J Pain. 1991;7:311–7
31. Wilkinson IM, Cohen SP. Epidural steroid injections. Curr Pain Headache Rep. 2012;16:50–9
32. Olmarker K, Larsson K. Tumor necrosis factor (alpha) and nucleus-pulposus-induced nerve root injury. Spine. 1998;23:2538–44
33. Igarashi T, Kikuchi S, Shubayev V, Myers RR. Exogenous tumor necrosis factor-alpha mimics nucleus pulposus-induced neuropathology. Spine. 2000;25:2975–80
34. Fukisaki M, Kobayaski I, Hara T, Sumikawa K. Symptoms of spinal stenosis after epidural steroid injection. Clin J Pain. 1998;14:148–51
35. Devor M, Wall PD, Catalan N. Systemic lidocaine silences ectopic neuroma and DRG discharge without blocking nerve conduction. Pain. 1992;48:261–8
36. DePalma MJ, Bhargava A, Slipman CW. A critical appraisal of the evidence for selective nerve root injection in the treatment of lumbosacral radiculopathy. Arch Phys Med Rehabil. 2005;86:1477–83
37. Cohen SP, White RL, Kurihara C, Larkin TM, Chang A, Griffith SR, Gilligan C, Larkin R, Morlando B, Pasquina PF, Yaksh TL, Nguyen C. Epidural steroids, etanercept, or saline in subacute sciatica: A multicenter, randomized trial. Ann Intern Med. 2012;156:551–9
38. Furlan AD, Pennick V, Bombardier C, van Tulder MEditorial Board, Cochrane Back Review Group. . 2009 updated method guidelines for systematic reviews in the Cochrane Back Review Group. Spine (Phila Pa 1976). 2009;34:1929–41
39. Liberati A, Altman DG, Tetzlaff J, Mulrow C, Gøtzsche PC, Ioannidis JP, Clarke M, Devereaux PJ, Kleijnen J, Moher D. The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: Explanation and elaboration. Ann Intern Med. 2009;151:W65–94
40. Jadad AR, Moore RA, Carroll D, Jenkinson C, Reynolds DJ, Gavaghan DJ, McQuay HJ. Assessing the quality of reports of randomized clinical trials: Is blinding necessary? Control Clin Trials. 1996;17:1–12
41. Chan CW, Peng P. Failed back surgery syndrome. Pain Med. 2011;12:577–6
42. Lee JW, Myung JS, Park KW, Yeom JS, Kim KJ, Kim HJ, Kang HS. Fluoroscopically guided caudal epidural steroid injection for management of degenerative lumbar spinal stenosis: Short-term and long-term results. Skeletal Radiol. 2010;39:691–9
43. Gatchel RJ, Gardea MA. Psychosocial issues: Their importance in predicting disability, response to treatment, and search for compensation. Neurol Clin. 1999;17:149–66
44. Pincus T, Burton A, Vogel S, Field AP. A systematic review of psychosocial factors as predictors of chronicity/disability in prospective cohorts of low back pain. Spine. 2002;27:E109–20
45. Elkayam O, Ben Itzhak S, Avrahami E, Meidan Y, Doron N, Eldar I, Keidar I, Liram N, Yaron M. Multidisciplinary approach to chronic back pain: Prognostic elements of the outcome. Clin Exp Rheumatol. 1996;14:281–8
46. Fishbain DA, Cole B, Cutler RB, Lewis J, Rosomoff HL, Rosomoff RS. A structured evidence-based review on the meaning of nonorganic physical signs: Waddell signs. Pain Med. 2003;4:141–81
47. Karppinen J, Ohinmaa A, Malmivaara A, Kurunlahti M, Kyllönen E, Pienimäki T, Nieminen P, Tervonen O, Vanharanta H. Cost effectiveness of periradicular infiltration for sciatica: Subgroup analysis of a randomized controlled trial. Spine (Phila Pa 1976). 2001;26:2587–95
48. Stojanovic MP, Vu TN, Caneris O, Slezak J, Cohen SP, Sang CN. The role of fluoroscopy in cervical epidural steroid injections: An analysis of contrast dispersal patterns. Spine (Phila Pa 1976). 2002;27:509–14
49. Liu SS, Melmed AP, Klos JW, Innis CA. Prospective experience with a 20-gauge Tuohy needle for lumbar epidural steroid injections: Is confirmation with fluoroscopy necessary? Reg Anesth Pain Med. 2001;26:143–6
50. Fredman B, Nun MB, Zohar E, Iraqi G, Shapiro M, Gepstein R, Jedeikin R. Epidural steroids for treating “failed back surgery syndrome”: Is fluoroscopy really necessary? Anesth Analg. 1999;88:367–72
51. Ferrante FM, Wilson SP, Iacobo C, Orav EJ, Rocco AG, Lipson S. Clinical classification as a predictor of therapeutic outcome after cervical epidural steroid injection. Spine (Phila Pa 1976). 1993;18:730–6
52. Anderberg L, Annertz M, Persson L, Brandt L, Säveland H. Transforaminal steroid injections for the treatment of cervical radiculopathy: A prospective and randomised study. Eur Spine J. 2007;16:321–8
53. Buenaventura RM, Datta S, Abdi S, Smith HS. Systematic review of therapeutic lumbar transforaminal epidural steroid injections. Pain Physician. 2009;12:233–51
54. Koes BW, Bouter LM, van der Heijden GJ. Methodological quality of randomized clinical trials on treatment efficacy in low back pain. Spine (Phila Pa 1976). 1995;20:228–35
55. Cohen SP, Strassels SA, Foster L, Marvel J, Williams K, Crooks M, Gross A, Kurihara C, Nguyen C, Williams N. Comparison of fluoroscopically guided and blind corticosteroid injections for greater trochanteric pain syndrome: Multicentre randomised controlled trial. BMJ. 2009;338:b1088
56. Ghahreman A, Bogduk N. Predictors of a favorable response to transforaminal injection of steroids in patients with lumbar radicular pain due to disc herniation. Pain Med. 2011;12:871–9
57. Liphofer JP, Theodoridis T, Becker GT, Koester O, Schmid G. [(Modic) signal alterations of vertebral endplates and their correlation to a minimally invasive treatment of lumbar disc herniation using epidural injections]. Rofo. 2006;178:1105–14
58. Buttermann GR. The effect of spinal steroid injections for degenerative disc disease. Spine J. 2004;4:495–505
59. Kapural L, Mekhail N, Bena J, McLain R, Tetzlaff J, Kapural M, Mekhail M, Polk S. Value of the magnetic resonance imaging in patients with painful lumbar spinal stenosis (LSS) undergoing lumbar epidural steroid injections. Clin J Pain. 2007;23:571–5
60. Jeong HS, Lee JW, Kim SH, Myung JS, Kim JH, Kang HS. Effectiveness of transforaminal epidural steroid injection by using a preganglionic approach: A prospective randomized controlled study. Radiology. 2007;245:584–90
61. Geurts JW, van Wijk RM, Stolker RJ, Groen GJ. Efficacy of radiofrequency procedures for the treatment of spinal pain: A systematic review of randomized clinical trials. Reg Anesth Pain Med. 2001;26:394–400
62. Downing SM. Validity: On meaningful interpretation of assessment data. Med Educ. 2003;37:830–7
63. Bland JM, Altman DG. Statistics Notes: Validating scales and indexes. BMJ. 2002;324:606–7
64. Halvorsen JG. Designing self-report instruments for family assessment. Fam Med. 1990;22:478–84
65. Carette S, Leclaire R, Marcoux S, Morin F, Blaise GA, St-Pierre A, Truchon R, Parent F, Levésque J, Bergeron V, Montminy P, Blanchette C. Epidural corticosteroid injections for sciatica due to herniated nucleus pulposus. N Engl J Med. 1997;336:1634–40
66. Hesla E, Breivik H. Epidural analgesia and epidural steroid injection for treatment of chronic low back pain and sciatica (in Norwegian). Tidsskr Nor Laegeforen. 1979;99:936–9
67. Iversen T, Solberg TK, Romner B, Wilsgaard T, Twisk J, Anke A, Nygaard O, Hasvold T, Ingebrigtsen T. Effect of caudal epidural steroid or saline injection in chronic lumbar radiculopathy: Multicentre, blinded, randomised controlled trial. BMJ. 2011;343:d5278
68. Nam HS, Park YB. Effects of transforaminal injection for degenerative lumbar scoliosis combined with spinal stenosis. Ann Rehabil Med. 2011;35:514–23
69. Ng L, Chaudhary N, Sell P. The efficacy of corticosteroids in periradicular infiltration for chronic radicular pain: A randomized, double-blind, controlled trial. Spine (Phila Pa 1976). 2005;30:857–62
70. Finckh A, Zufferey P, Schurch MA, Balagué F, Waldburger M, So AK. Short-term efficacy of intravenous pulse glucocorticoids in acute discogenic sciatica. A randomized controlled trial. Spine (Phila Pa 1976). 2006;31:377–81
71. Roncoroni C, Baillet A, Durand M, Gaudin P, Juvin R. Efficacy and tolerance of systemic steroids in sciatica: A systematic review and meta-analysis. Rheumatology (Oxford). 2011;50:1603–11
72. Song F, Altman DG, Glenny AM, Deeks JJ. Validity of indirect comparison for estimating efficacy of competing interventions: Empirical evidence from published meta-analyses. BMJ. 2003;326:472
73. Arden NK, Price C, Reading I, Stubbing J, Hazelgrove J, Dunne C, Michel M, Rogers P, Cooper CWEST Study Group. . A multicentre randomized controlled trial of epidural corticosteroid injections for sciatica: The WEST study. Rheumatology (Oxford). 2005;44:1399–406
74. Becker C, Heidersdorf S, Drewlo S, de Rodriguez SZ, Krämer J, Willburger RE. Efficacy of epidural perineural injections with autologous conditioned serum for lumbar radicular compression: An investigator-initiated, prospective, double-blind, reference-controlled study. Spine (Phila Pa 1976). 2007;32:1803–8
75. Béliveau P. A comparison between epidural anaesthesia with and without corticosteroid in the treatment of sciatica. Rheumatol Phys Med. 1971;11:40–3
76. Breivik H, Hesla PE, Molnar I, Lind B. Treatment of chronic low back pain and sciatica. Comparison of caudal epidural injections of bupivacaine and methylprednisolone with bupivacaine followed by saline. Adv Pain Res Therapy. 1976;1:927–32
77. Bush K, Hillier S. A controlled study of caudal epidural injections of triamcinolone plus procaine for the management of intractable sciatica. Spine (Phila Pa 1976). 1991;16:572–5
78. Cohen SP, Bogduk N, Dragovich A, Buckenmaier CC III, Griffith S, Kurihara C, Raymond J, Richter PJ, Williams N, Yaksh TL. Randomized, double-blind, placebo-controlled, dose-response, and preclinical safety study of transforaminal epidural etanercept for the treatment of sciatica. Anesthesiology. 2009;110:1116–26
79. Cuckler JM, Bernini PA, Wiesel SW, Booth RE Jr, Rothman RH, Pickens GT. The use of epidural steroids in the treatment of lumbar radicular pain. A prospective, randomized, double-blind study. J Bone Joint Surg Am. 1985;67:63–6
80. Dilke TF, Burry HC, Grahame R. Extradural corticosteroid injection in management of lumbar nerve root compression. Br Med J. 1973;2:635–7
81. Ghahreman A, Ferch R, Bogduk N. The efficacy of transforaminal injection of steroids for the treatment of lumbar radicular pain. Pain Med. 2010;11:1149–68
82. Karppinen J, Malmivaara A, Kurunlahti M, Kyllönen E, Pienimäki T, Nieminen P, Ohinmaa A, Tervonen O, Vanharanta H. Periradicular infiltration for sciatica: A randomized controlled trial. Spine (Phila Pa 1976). 2001;26:1059–67
83. Klenerman L, Greenwood R, Davenport HT, White DC, Peskett S. Lumbar epidural injections in the treatment of sciatica. Br J Rheumatol. 1984;23:35–8
84. Kraemer J, Ludwig J, Bickert U, Owczarek V, Traupe M. Lumbar epidural perineural injection: A new technique. Eur Spine J. 1997;6:357–61
85. Manchikanti L, Singh V, Cash KA, Pampati V, Damron KS, Boswell MV. Preliminary results of a randomized, equivalence trial of fluoroscopic caudal epidural injections in managing chronic low back pain: Part 2—Disc herniation and radiculitis. Pain Physician. 2008;11:801–15
86. Manchikanti L, Singh V, Cash KA, Pampati V, Datta S. Preliminary results of a randomized, equivalence trial of fluoroscopic caudal epidural injections in managing chronic low back pain: Part 3—Post surgery syndrome. Pain Physician. 2008;11:817–31
87. Manchikanti L, Cash KA, McManus CD, Pampati V, Smith HS. One-year results of a randomized, double-blind, active controlled trial of fluoroscopic caudal epidural injections with or without steroids in managing chronic discogenic low back pain without disc herniation or radiculitis. Pain Physician. 2011;14:25–6
88. Manchikanti L, Malla Y, Cash KA, McManus CD, Pampati V. Fluoroscopic cervical interlaminar epidural injections in managing chronic pain of cervical postsurgery syndrome: Preliminary results of a randomized, double-blind, active control trial. Pain Physician. 2012;15:13–5
89. Manchikanti L, Singh V, Cash KA, Pampati V, Damron KS, Boswell MV. Effect of fluoroscopically guided caudal epidural steroid or local anesthetic injections in the treatment of lumbar disc herniation and radiculitis: A randomized, controlled, double blind trial with a two-year follow-up. Pain Physician. 2012;15:273–86
90. Manchikanti L, Cash KA, McManus CD, Pampati V, Fellows B. Results of 2-year follow-up of a randomized, double-blind, controlled trial of fluoroscopic caudal epidural injections in central spinal stenosis. Pain Physician. 2012;15:371–84
91. Manchikanti L, Cash KA, McManus CD, Damron KS, Pampati V, Falco FJ. Lumbar interlaminar epidural injections in central spinal stenosis: Preliminary results of a randomized, double-blind, active control trial. Pain Physician. 2012;15:51–3
92. Manchikanti L, Malla Y, Cash KA, McManus CD, Pampati V. Fluoroscopic epidural injections in cervical spinal stenosis: Preliminary results of a randomized, double-blind, active control trial. Pain Physician. 2012;15:E59–70
93. Manchikanti L, Cash KA, McManus CD, Pampati V, Benyamin R. Fluoroscopic lumbar interlaminar epidural injections in managing chronic lumbar axial or discogenic pain. J Pain Res. 2012;5:301–11
94. Manchikanti L, Cash KA, Pampati V, Wargo BW, Malla Y. Management of chronic pain of cervical disc herniation and radiculitis with fluoroscopic cervical interlaminar epidural injections. Int J Med Sci. 2012;9:424–34
95. Manchikanti L, Singh V, Cash KA, Pampati V, Datta S. Fluoroscopic caudal epidural injections in managing post lumbar surgery syndrome: Two-year results of a randomized, double-blind, active-control trial. Int J Med Sci. 2012;9:582–91
96. Mathews JA, Mills SB, Jenkins VM, Grimes SM, Morkel MJ, Mathews W, Scott CM, Sittampalam Y. Back pain and sciatica: Controlled trials of manipulation, traction, sclerosant and epidural injections. Br J Rheumatol. 1987;26:416–23
97. Meadeb J, Rozenberg S, Duquesnoy B, Kuntz JL, Le Loët X, Sebert JL, Le Goff P, Fallut M, Marty M, Blévin S, Guggenbuhl P, Chalès G, Duvauferrier R. Forceful sacrococcygeal injections in the treatment of postdiscectomy sciatica. A controlled study versus glucocorticoid injections. Joint Bone Spine. 2001;68:43–9
98. Price C, Arden N, Coglan L, Rogers P. Cost-effectiveness and safety of epidural steroids in the management of sciatica. Health Technol Assess. 2005;9:1–58, iii
99. Ridley MG, Kingsley GH, Gibson T, Grahame R. Outpatient lumbar epidural corticosteroid injection in the management of sciatica. Br J Rheumatol. 1988;27:295–9
100. Rocco AG, Frank E, Kaul AF, Lipson SJ, Gallo JP. Epidural steroids, epidural morphine and epidural steroids combined with morphine in the treatment of post-laminectomy syndrome. Pain. 1989;36:297–3
101. Rogers P, Nash T, Schiller D, Norman J. Epidural steroids for sciatica. Pain Clinic. 1992;5:67–2
102. Sayegh FE, Kenanidis EI, Papavasiliou KA, Potoupnis ME, Kirkos JM, Kapetanos GA. Efficacy of steroid and nonsteroid caudal epidural injections for low back pain and sciatica: A prospective, randomized, double-blind clinical trial. Spine (Phila Pa 1976). 2009;34:1441–7
103. Snoek W, Weber H, Jørgensen B. Double blind evaluation of extradural methyl prednisolone for herniated lumbar discs. Acta Orthop Scand. 1977;48:635–41
104. Stav A, Ovadia L, Sternberg A, Kaadan M, Weksler N. Cervical epidural steroid injection for cervicobrachialgia. Acta Anaesthesiol Scand. 1993;37:562–6
105. Tafazal S, Ng L, Chaudhary N, Sell P. Corticosteroids in peri-radicular infiltration for radicular pain: A randomised double blind controlled trial. One year results and subgroup analysis. Eur Spine J. 2009;18:1220–5
106. Vad VB, Bhat AL, Lutz GE, Cammisa F. Transforaminal epidural steroid injections in lumbosacral radiculopathy: A prospective randomized study. Spine (Phila Pa 1976). 2002;27:11–6
107. Valat JP, Giraudeau B, Rozenberg S, Goupille P, Bourgeois P, Micheau-Beaugendre V, Soubrier M, Richard S, Thomas E. Epidural corticosteroid injections for sciatica: A randomised, double blind, controlled clinical trial. Ann Rheum Dis. 2003;62:639–43
108. Wilson-MacDonald J, Burt G, Griffin D, Glynn C. Epidural steroid injection for nerve root compression. A randomised, controlled trial. J Bone Joint Surg Br. 2005;87:352–5
109. Dworkin RH, Turk DC, Farrar JT, Haythornthwaite JA, Jensen MP, Katz NP, Kerns RD, Stucki G, Allen RR, Bellamy N, Carr DB, Chandler J, Cowan P, Dionne R, Galer BS, Hertz S, Jadad AR, Kramer LD, Manning DC, Martin S, McCormick CG, McDermott MP, McGrath P, Quessy S, Rappaport BA, Robbins W, Robinson JP, Rothman M, Royal MA, Simon L, Stauffer JW, Stein W, Tollett J, Wernicke J, Witter JIMMPACT. . Core outcome measures for chronic pain clinical trials: IMMPACT recommendations. Pain. 2005;113:9–19
110. Owlia MB, Salimzadeh A, Alishiri G, Haghighi A. Comparison of two doses of corticosteroid in epidural steroid injection for lumbar radicular pain. Singapore Med J. 2007;48:241–5
111. McCahon RA, Ravenscroft A, Hodgkinson V, Evley R, Hardman J. A pilot study of the dose-response of caudal methylprednisolone with levobupivacaine in chronic lower back pain. Anaesthesia. 2011;66:595–3
112. Kang SS, Hwang BM, Son HJ, Cheong IY, Lee SJ, Lee SH, Chung TY. The dosages of corticosteroid in transforaminal epidural steroid injections for lumbar radicular pain due to a herniated disc. Pain Physician. 2011;14:361–70
113. Rabinovitch DL, Peliowski A, Furlan AD. Influence of lumbar epidural injection volume on pain relief for radicular leg pain and/or low back pain. Spine J. 2009;9:509–17
114. Dooley JF, McBroom RJ, Taguchi T, Macnab I. Nerve root infiltration in the diagnosis of radicular pain. Spine (Phila Pa 1976). 1988;13:79–3
115. Plastaras CT, Heller DS, Sorosky BS, Houle TT. Pain reproduction during lumbosacral transforaminal epidural steroid injection does not affect outcome. J Back Musculoskeletal Rehab. 2006;19:57–60
116. Kaptchuk TJ, Stason WB, Davis RB, Legedza AR, Schnyer RN, Kerr CE, Stone DA, Nam BH, Kirsch I, Goldman RH. Sham device v inert pill: Randomised controlled trial of two placebo treatments. BMJ. 2006;332:391–7
117. Rathmell JP, Aprill C, Bogduk N. Cervical transforaminal injection of steroids. Anesthesiology. 2004;100:1595–600
118. Houten JK, Errico TJ. Paraplegia after lumbosacral nerve root block: Report of three cases. Spine J. 2002;2:70–5
119. Kennedy DJ, Dreyfuss P, Aprill CN, Bogduk N. Paraplegia following image-guided transforaminal lumbar spine epidural steroid injection: Two case reports. Pain Med. 2009;10:1389–94
120. Whynes DK, McCahon RA, Ravenscroft A, Hardman J. Cost effectiveness of epidural steroid injections to manage chronic lower back pain. BMC Anesthesiol. 2012;12:26
121. Gunal I, Karatosun V. Avascular necrosis of the femoral heads after single corticosteroid injection. CMAJ. 2006;175:31
122. Even JL, Crosby CG, Song Y, McGirt MJ, Devin CJ. Effects of epidural steroid injections on blood glucose levels in patients with diabetes mellitus. Spine (Phila Pa 1976). 2012;37:E46–50
123. Davis K, Prater A, Fluker SA, Klein R. A difficult case to swallow: Herpes esophagitis after epidural steroid injection. Am J Ther. 2011 [Epub ahead of print ]
124. Ward A, Watson J, Wood P, Dunne C, Kerr D. Glucocorticoid epidural for sciatica: Metabolic and endocrine sequelae. Rheumatology (Oxford). 2002;41:68–1
125. Davey J, Turner RM, Clarke MJ, Higgins JP. Characteristics of meta-analyses and their component studies in the Cochrane Database of Systematic Reviews: A cross-sectional, descriptive analysis. BMC Med Res Methodol. 2011;11:160
126. Herbison P, Hay-Smith J, Gillespie WJ. Meta-analyses of small numbers of trials often agree with longer-term results. J Clin Epidemiol. 2011;64:145–53
127. Bucher HC, Guyatt GH, Griffith LE, Walter SD. The results of direct and indirect treatment comparisons in meta-analysis of randomized controlled trials. J Clin Epidemiol. 1997;50:683–91
128. Hjermstad MJ, Fayers PM, Haugen DF, Caraceni A, Hanks GW, Loge JH, Fainsinger R, Aass N, Kaasa SEuropean Palliative Care Research Collaborative (EPCRC). . Studies comparing Numerical Rating Scales, Verbal Rating Scales, and Visual Analogue Scales for assessment of pain intensity in adults: A systematic literature review. J Pain Symptom Manage. 2011;41:1073–93
129. Ponce de Leon S, Lara-Muñoz C, Feinstein AR, Wells CK. A comparison of three rating scales for measuring subjective phenomena in clinical research. II. Use of experimentally controlled visual stimuli. Arch Med Res. 2004;35:157–62
130. Akinpelu AO, Olowe OO. Correlative study of 3 pain rating scales among obstetric patients. Afr J Med Med Sci. 2002;31:123–6
131. Pinto RZ, Maher CG, Ferreira ML, Hancock M, Oliveira VC, McLachlan AJ, Koes B, Ferreira PH. Epidural corticosteroid injections in the management of sciatica: A systematic review and meta-analysis. Ann Intern Med. 2012;157:865–77
132. MacVicar J, King W, Landers MH, Bogduk N. The effectiveness of lumbar transforaminal injection of steroids: A comprehensive review with systematic analysis of the published data. Pain Med. 2013;14:14–8
133. Novak S, Nemeth WC. The basis for recommending repeating epidural steroid injections for radicular low back pain: A literature review. Arch Phys Med Rehabil. 2008;89:543–52
© 2013 American Society of Anesthesiologists, Inc.
Publication of an advertisement in Anesthesiology Online does not constitute endorsement by the American Society of Anesthesiologists, Inc. or Lippincott Williams & Wilkins, Inc. of the product or service being advertised.