Andrew Engel

The effectiveness and risks of fluoroscopically guided cervical transforaminal injections of steroids: a systematic review with comprehensive analysis of the published data.

OBJECTIVE To determine the effectiveness and risks of fluoroscopically guided cervical transforaminal injection of corticosteroids in the treatment of radicular pain. DESIGN Systematic review of the literature with comprehensive analysis of the published data. INTERVENTIONS Three reviewers with formal training in evidence-based medicine searched the literature on fluoroscopically guided cervical transforaminal injection of steroids (CTFIS). Each reviewer independently assessed the methodology of studies found and appraised the quality of the evidence presented. OUTCOME MEASURES The primary outcome assessed was relief of radicular pain. Other outcomes such as reduction in surgery rate and complications were noted if reported. The evidence on each outcome was appraised in accordance with the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) system of evaluating evidence. RESULTS The searches yielded 16 primary publications on effectiveness. Available evidence, derived mainly from observational studies, suggests that approximately 50% of patients experience 50% relief of radicular pain for at least 4 weeks after CTFIS, and the intervention may have surgery-sparing effects. The literature also contains 21 articles with primary reports of serious complications, including 13 deaths and many catastrophic neurological injuries. The evidence of pain-relieving effects, of surgery-sparing effects, and of risks of CTFIS were all rated as of very low quality according to the GRADE system. CONCLUSIONS In patients with cervical radicular pain, fluoroscopically guided CTFIS may be effective in easing pain and reducing need for surgery. However, the evidence of effectiveness is of very low quality, and the benefits of the procedure are compromised by the risks of serious complications.

Fluoroscopically Guided Diagnostic and Therapeutic Intra-Articular Sacroiliac Joint Injections: A Systematic Review.

OBJECTIVE To assess the validity of fluoroscopically guided diagnostic intra-articular injections of local anesthetic and effectiveness of intra-articular steroid injections in treating sacroiliac joint (SIJ) pain. DESIGN Systematic review. INTERVENTIONS Ten reviewers independently assessed 45 publications on diagnostic validity or effectiveness of fluoroscopically guided intra-articular SIJ injections. OUTCOME MEASURES For diagnostic injections, the primary outcome was validity; for therapeutic injections, analgesia. Secondary outcomes were also described. RESULTS Of 45 articles reviewed, 39 yielded diagnostic data on physical exam findings, provocation tests, and SIJ injections for diagnosing SIJ pain, and 15 addressed therapeutic effectiveness. When confirmed by comparative local anesthetic blocks with a high degree of pain relief, no single physical exam maneuver predicts response to diagnostic injections. When at least three physical exam findings are present, sensitivity, and specificity increases significantly. The prevalence of SIJ pain is likely 20-30% among patients that have suspected SIJ pain based on history and physical examination. This estimate may be higher in certain subgroups such as the elderly and fusion patients. Two randomized controlled trials and multiple observational studies supported the effectiveness of therapeutic sacroiliac joint injections. CONCLUSIONS Based on this literature, it is unclear whether image-guided intra-articular diagnostic injections of local anesthetic predict positive responses to therapeutic agents. The overall quality of evidence is moderate for the effectiveness of therapeutic SIJ injections.

The Effectiveness and Risks of Fluoroscopically-Guided Cervical Medial Branch Thermal Radiofrequency Neurotomy: A Systematic Review with Comprehensive Analysis of the Published Data

OBJECTIVE To determine the effectiveness and risks of fluoroscopically-guided cervical medial branch thermal radiofrequency neurotomy (CMBTRFN) for treating chronic neck pain of zygapophysial joint origin. DESIGN Systematic review of the literature with comprehensive analysis of the published data. INTERVENTIONS Four reviewers formally trained in evidence-based medicine searched the literature on CMBTRFN. Each assessed the methodologies of studies found and appraised the quality of evidence presented. OUTCOME MEASURES The primary outcomes assessed were 100% relief of pain 6 and 12 months after treatment. Other outcomes were noted if reported. The evidence was evaluated in accordance with the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) system. RESULTS The searches yielded eight primary publications on the effectiveness of the procedure. The evidence shows a majority of patients were pain free at 6 months and over a third were pain free at 1 year. The number needed to treat for complete pain relief at 6 months is 2. The evidence of effectiveness is of high quality according to the GRADE system. Twelve papers were found reporting unwanted effects, most of which are minor and temporary. No serious complications have ever been reported from procedures performed according to the published guidelines. The evidence of risks is of low quality according to the GRADE system. CONCLUSIONS If performed as described in the International Spine Intervention Society Guidelines, fluoroscopically-guided CMBTRFN is effective for abolishing zygapophysial joint pain and carries only minor risks.

Differing Philosophical Approaches to Treating Patients

Dear Editor, We appreciate that Manchikanti et al. carefully read our review of cervical medial branch thermal radiofrequency neurotomy (CMBTRFN) [1]. Their detailed letter [2] highlights important differences in methodology and philosophic approach to patient care, which we shall address. With respect to methodology, Manchikanti et al. titled their letter “Systematic Review of Cervical Medial Branch Thermal Radiofrequency Neurotomy is not Based on Peer Review Published Methodology.” They point out that our review [1] neither meets the Institute of Medicine’s (IOM) standard nor uses the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) [2]; but these are not the only standards or tools. Our review of CMBTRFN was completed in accordance with the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) system. Of course, GRADE has been widely published and subject to extensive peer-review [3–18], and …

Risks and Benefits of Ceasing or Continuing Anticoagulant Medication for Image-Guided Procedures for Spine Pain: A Systematic Review

Objective To determine the risks of continuing or ceasing anticoagulant or antiplatelet medications prior to image-guided procedures for spine pain. Design Systematic review of the literature with comprehensive analysis of the published data. Interventions Following a search of the literature for studies pertaining to spine pain interventions in patients on anticoagulant medication, seven reviewers appraised the studies identified and assessed the quality of evidence presented. Outcome Measures Evidence was sought regarding risks associated with either continuing or ceasing anticoagulant and antiplatelet medication in patients having image-guided interventional spine procedures. The evidence was evaluated in accordance with the Grades of Recommendation, Assessment, Development, and Evaluation system. Results From a source of 120 potentially relevant articles, 14 provided applicable evidence. Procedures involving interlaminar access carry a nonzero risk of hemorrhagic complications, regardless of whether anticoagulants are ceased or continued. For other procedures, hemorrhagic complications have not been reported, and case series indicate that they are safe when performed in patients who continue anticoagulants. Three articles reported the adverse effects of ceasing anticoagulants, with serious consequences, including death. Conclusions Other than for interlaminar procedures, the evidence does not support the view that anticoagulant and antiplatelet medication must be ceased before image-guided spine pain procedures. Meanwhile, the evidence shows that ceasing anticoagulants carries a risk of serious consequences, including death. Guidelines on the use of anticoagulants should reflect these opposing bodies of evidence.

High-pressure discography may injure discs

We thank Engel et al. and Koetsier et al. for their interest in our study. The ante hoc study design planned for head-to-head statistical comparisons between primary outcomes: by year 10, there were significant differences between the primary clinical outcomes of patients with punctured or injected discs and those of the controls, with a statistically significant difference defined as p<.05. The authors of the letter have artificially juggled the data post hoc to produce an isolated comparison demonstrating a minor confidence interval overlap wherein a threefold difference is minimized. The ante hoc primary analysis is necessarily a stronger and more confident analysis. This is a most basic tenet of biostatistics. Adverse outcomes were found in every single primary ante hoc comparison—a powerful unidirectional difference across the board in all study variables. Statistical analysis demonstrated that for each of these variables, the difference was statistically significant and was not a statistical “trend.” The “chance” of a random unidirectional and adverse outcome in the discography group is exceedingly small. The authors of the letter also inaccurately state that intradiscal pressure levels used during the discography in our study reached 100 psi above opening pressure. In fact, the injection had value set at 100 psi at the pressure relief valve (at the syringe level), and the most any subject received was 70–80 psi above the opening pressure (commonly about 20 psi). No patient was subjected to 100 psi above opening pressure. These tests were done in the 1990s when levels of 100 psi above opening pressure values were routinely used. We examined the outcomes of discs in our data set that had received a psi of 50 or more and compared these with discs with lower end pressures to determine if higher pressures resulted in greater, single disc–specific, adverse events (eg, patient requiring L4–L5 discectomy). After controlling for baseline disc degeneration, we found that the data trended in the opposite direction: discs with end pressures <50 psi were more likely to demonstrate accelerated degeneration after discography, greater loss of signal and disc height, and more frequent herniation. Finally, the argument supporting a 50 psi limit has been purported by Dr Nikolai Bogduk and originated in an early study by Derby et al [1]. It should be noted that the study designers, discographers, test subjects, and authors were in many cases the same individuals in the study reported by Derby et al [1]. This study, the primary source for a 50 psi limit of pressurization, is severely flawed and cannot be seriously considered. Lastly, the authors of the letter point out the fact that some of our study subjects were asymptomatic volunteers. According to Sackett and Haynes, the Journal of the American Medical Association, and the British Medical Journal guidelines for examining diagnostic tests, the starting point of test examination very often should be subjects known not to have the disease in question. This was our starting point for examining provocative lumbar discography as a test for discogenic low back pain. It failed to pass even the lowest bar of validity.

Finding an Answer: Comments on a Randomized Trial of Epidural Glucocorticoid Injections for Lumbar Spinal Stenosis

Recently, Friedly et al. published a study on the effectiveness of epidural injections of steroids (ESIs) for lumbar spinal stenosis (LSS) [1]. Because of its apparent implications for clinical practice, this study attracted comments both in the professional [2] and lay press [3]. However, the study prompts reflection on a number of issues that extend beyond the conventional appraisal of a study. Those issues pertain to how physicians think about a condition, how it should be treated, and how to best assess the effectiveness of that treatment. The following article addresses those issues in the interest of informing physicians about how contemporary practices are confounded by lack of diagnostic discipline, and how this makes the conduct of controlled trials complicated and, therefore, makes the results difficult to assess. The cardinal issues are the symptoms of LSS; the diagnosis of LSS; the rationale for treatment; the consequent appropriate selection of patients; the outcomes assessment, either in practice or in a study including the reporting of those outcomes; and the need for rigorous control of the technical performance of the therapeutic intervention. Each of these issues has a critical bearing on appraising not only the literature on LSS, but also on how physicians treat this condition in conventional practice. The literature is profuse with heterogeneity in symptomology related to LSS. While there is no consensus in the current literature on acceptable LSS symptoms, the most commonly quoted symptoms are neurogenic claudication, radicular pain, and low back pain (LBP). Additional symptoms commonly mentioned in literature were fatigue and loss of power in the legs, anesthesia, and a feeling of numbness in the sacral dermatomes. In an attempt to achieve consensus, Katz et al. in 1995 published symptoms most strongly associated with the diagnosis of LSS (likelihood ratio ≥ 2), …

All Failures Count

Dear Editor, Rauck et al. notably completed a study of opioids in 510 patients with chronic low back pain [1]. All 510 patients were at the start converted from their current opioid to hydrocodone extended-release (HC-ER). During the initial conversion, 208 patients failed treatment with HC-ER and were not included in step two of the study. The remaining 302 of the 510 patients were evenly split into treatment and placebo groups. The HC-ER success rate was calculated based on the patients in step two only. The …

Not All Injections Are the Same

To the Editor: In metaphorical terms, a problem arises when good apples are pooled with bad apples; they all get tarred with the same brush. This principle applies when all studies pertaining to spinal injections of steroids are pooled, as if they are all equal. Subsequently, the lay press publicizes sweeping conclusions such as “injecting any liquid, even plain saline solution, works just as well.”1 Such statements bring all injections into disrepute. Admirably, Bicket et al.2 used an ingenious statistical exercise to explore the conjecture that epidural injections of other agents are not fair controls as epidural injections of steroids. However, in their exploration, they pooled data on cervical and lumbar injections, on image-guided injections and blind injections, and on interlaminar, caudal, and transforaminal injections; they even included studies that did not involve steroids. Given that these various targets and techniques differ with respect to pathology, anatomy, technical accuracy, and evidence base, such pooling might not be legitimate, and at least clouds the true picture. Prominent among the studies analyzed is that of Ghahreman et al.3 which, indeed, the authors rank as rigorous. In the statistical analysis, this study stands out as an outlier; but it is also different in other respects. It is one of the few studies included in the review that used transforaminal injections, and it is the only study that actually addressed prospectively the very question being explored by the meta-analysis. In that regard, its results happen to contradict the conclusions of the review. It showed that the efficacy of transforaminal injection of steroid is significantly greater than that of transforaminal injection of nonsteroid. The authors of the review have referred to a conclusion that detecting a difference between treatment and control groups would not be practical but have not stated that this conclusion related specifically to long-term (12 months) outcomes. It would have been more courteous, and more informative, had the authors stratified their analysis by region and by technique. Their conclusions might still apply to classical, blind epidural injections, but they would not apply to lumbar transforaminal injections. Lumbar transforaminal injection of steroids is significantly more often effective than transforaminal injection of either local anesthetic or saline, and intramuscular injection of either steroids or saline, and by the same magnitude in all cases. It may be that these data could be overturned by future studies, but at present, they are the only direct data on this procedure. Those data defy the sweeping generalizations of the review, which are sensationalized by the lay press, and which serve the purpose of those who wish to deny reimbursement for epidural injections. Meta-analysis of circumstantial evidence does not constitute proof; is not a substitute for well-designed controlled trials that address the issue. It serves only to raise an intriguing proposition worthy of studies that prospectively test it. In this dural incision. Renal blood flow was similarly trended using laser-Doppler probes placed surgically against the renal capsule. Red cell flux monitoring was plotted against cerebral and renal perfusion pressure respectively as a definitive standard pressure autoregulation curve. The aim of the study was to test the accuracy of separately measured metrics of dynamic vascular reactivity derived from near-infrared spectroscopy: the hemoglobin volume index describing cerebral vascular reactivity and the renovascular reactivity index to describe vascular reactivity in the kidney. Although not the primary aim of that study, it was observed in some animals that renal blood flow fell during hemorrhagic shock before any change in arterial blood pressure occurred. Although, cardiac output was not directly monitored, these findings of reduced renal blood flow despite no change in blood pressure can be explained only by a reduced cardiac output. This was demonstrated by the example data shown in the figures of the article. Thus, these findings support our contention that renal blood flow is dependent on both blood flow (cardiac output or cardiopulmonary bypass) and blood pressure as we state in our editorial.