Byron J. Schneider

A minimum of 5-year follow-up after lumbar transforaminal epidural steroid injections in patients with lumbar radicular pain due to intervertebral disc herniation

BACKGROUND CONTEXTnPatients with lumbosacral radiculopathy from an intervertebral disc herniation are frequently treated by transforaminal epidural steroid injections (TFESIs). The long-term outcomes of these patients are poorly described.nnnPURPOSEnWe aimed to determine the long-term outcomes for a homogenous group of patients with acute unilateral lumbar radicular pain due to single-level herniated nucleus after lumbar epidural steroid injection at ≥5 years.nnnDESIGNnThis is a prospective cohort study.nnnPATIENT SAMPLEnSubjects enrolled into a previous reported multi-institutional randomized controlled trial, ≥18 years old with single leg radicular pain rating ≥4/10 for less than 6 months duration, with radiographic imaging demonstrating an anatomically congruent single-level herniated nucleus pulposus.nnnOUTCOME MEASURESnPresence of recurrent or persistent pain, pain within the previous week, current opioid use for radicular symptoms, additional spine injections for radicular pain, progression to surgery, and unemployment due to pain as determined by independent phone interview at least 5 years after enrolment due to the initial pain complaint were the outcome measures.nnnMETHODSnAll patients initially underwent a single-level lumbar TFESIs due to failure of conservative care, but could elect to pursue surgical intervention or repeat injections through shared decision making with the treating physician when and if pain control was deemed inadequate. After ≥5 years, an independent assessor contacted the subjects by phone and performed a standardized interview to determine outcomes. Fisher exact test was used to compare outcomes for those who pursued versus those who did not pursue surgery.nnnRESULTSnDuring the recruitment period (December 2008 to December 2012), 78 subjects were enrolled. At 5 years, 39 (50%) of the 78 subjects were reachable for independent phone follow-up. Of these, 30 (76.9%, 95% confidence interval [CI] 61.7%-87.4%) had a history of recurrent pain since the initial TFESI. However, only 9 (23.1%, 95% CI 12.7%-38.3%) had current pain, while 3 (7.7%, 95% CI 2.7%-20.3%) were currently taking opioid medications. Nine (23.1%, 95% CI 12.7%-38.3%) had received additional TFESIs, and 19 (48.7%, 95% CI 33.9%-63.8%) had received surgery. Only 3 (7.7%, 95% CI 2.7%-20.3%) were unemployed due to related pain at time of follow-up. When comparing the group that had surgery versus those that did not, there were no differences in the rates of recurrent pain (16, 84.2% vs. 14, 70.0%, p=.81), current pain (6, 31.6% vs. 3, 15.0%, p=.47), opioid use (2, 10.5% vs. 1, 5.0%, p=1.00), rate of additional injections (6, 31.6% vs. 3, 15.0%, p=.47), or unemployment status (2, 10.5% vs. 1, 5.0%, p=1.00).nnnCONCLUSIONSnDespite a high success rate at 6 months, the majority of subjects experienced a recurrence of symptoms at some time during the subsequent 5 years. Fortunately, few reported current symptoms, and a small minority required additional injections, surgery, or opioid pain medications. Lumbar disc herniation is a disease that can be effectively treated in the short-term by TFESI or surgery, but long-term recurrence rates are high regardless of treatment received.

Particulate or Nonparticulate Steroids for Lumbar Transforaminal Injections

Fact: All particulate corticosteroid preparations have been implicated in rare cases of paraplegia, whereas no definitive evidence exists of paraplegia resulting from injection of nonparticulate steroids. Studies directly comparing the effectiveness of particulate and nonparticulate steroids largely show no differences between the two, with respect to relief of pain, restoration of function, or rate of spine surgery. There is no evidence-based rationale for the routine use of particulate steroids in lumbar transforaminal injections, given the increased risk of paraplegia.

Does Immediate Pain Relief After an Injection into the Sacroiliac Joint with Anesthetic and Corticosteroid Predict Subsequent Pain Relief

ObjectivesnTo determine if immediate pain response following an injection with local anesthetic and corticosteroid predicts subsequent relief.nnnDesignnProspective observational cohort.nnnSettingnAn institutional review board-approved prospective study from a single academic medical center.nnnMethodsnPatients with clinical diagnosis of sacroiliac (SIJ) pain and referred for SIJ injection were enrolled; 1u2009cc of 2% lidocaine and 1u2009cc of triamcinolone 40u2009mg/mL were injected into the SIJ. Pain score on 0-10 numeric rating scale (NRS) during provocation maneuvers was recorded immediately before injection, immediately after injection, and at two and four weeks of follow-up. Oswestry Disability Index (ODI) was also recorded.nnnResultsnVarious cutoffs were identified to establish positive anesthetic response and successful outcomes at follow-up. These were used to calculated likelihood ratios. Of those with 100% anesthetic response, six of 11 (54.5%, 95% confidence interval [CI]+/-29.4%, +LR 2.6, 95% CIu2009=u20091.1-5.9) demonstrated 50% or greater pain relief at follow-up, and four of 11 (36.5%, 95% CI+/-28.4%, +LR 3.00, 95% CIu2009=u20091.4-5.1) had 100% relief at two to four weeks. Fourteen of 14 (100%, 95% CI+/-21.5%, -LR 0.0, 95% CIu2009=u20090.0-2.1) with an initial negative block failed to achieve 100% relief at follow-up.nnnConclusionsnPatients who fail to achieve initial relief after SIJ injection with anesthetic and steroid are very unlikely to achieve significant pain relief at follow-up; negative likelihood ratios (LR) in this study, based on how success is defined, range between 0 and 0.9. Clinically significant positive likelihood ratios of anesthetic response to SIJ injection are more limited and less robust, but are valuable in predicting 50% relief or 100% relief at two to four weeks.

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

ObjectivenTo determine the risks of continuing or ceasing anticoagulant or antiplatelet medications prior to image-guided procedures for spine pain.nnnDesignnSystematic review of the literature with comprehensive analysis of the published data.nnnInterventionsnFollowing 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.nnnOutcome MeasuresnEvidence 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.nnnResultsnFrom 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.nnnConclusionsnOther 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.

Driving After an Epidural Steroid Injection Without Sedation

Fact: Driving safety is potentially compromised by the use of local anesthetic included in the epidural injectate even if sedation is not used during the procedure. Further, rare cases of delayed-onset visual and sensorimotor impairments, independent of the effects of local anesthetic, have been associated with ESI. Therefore, clinicians may consider rescheduling an ESI procedure if the patient does not have a driver.

Effect of pre-injection opioid use on post-injection patient-reported outcomes following epidural steroid injections for radicular pain

BACKGROUND CONTEXTnChronic opioid therapy is associated with worse patient-reported outcomes (PROs) following spine surgery. However, little literature exists on the relationship between opioid use and PROs following epidural steroid injections for radicular pain.nnnPURPOSEnWe evaluated the association between pre-injection opioid use and PROs following spine epidural steroid injection.nnnSTUDY DESIGNnThis study is a retrospective analysis of a prospective longitudinal registry database.nnnPATIENT SAMPLEnA total of 392 patients within our database who were undergoing epidural steroid injections (ESIs) at our institution for degenerative structural spine diagnoses and met our inclusion criteria were included in this study.nnnOUTCOME MEASURESnPatient-reported outcomes for disability (Oswestry Disability Index/Neck Disability Index [ODI/NDI)]), quality of life (EuroQol-5D [EQ-5D]), and pain (Numerical Rating Scale scores for back pain, neck pain, leg pain, and arm pain [NRS-BP/NP/LP/AP]) were assessed at baseline and at 3 and 12 months post-injection.nnnMETHODSnMultivariable proportional odds logistic regression models were created to examine the relationship between pre-injection opioid use and post-injection PROs. A logistic regression with Bayesian Markov chain Monte Carlo parameter estimation was used to investigate a possible cutoff value of pre-injection opioid use above which the effectiveness of ESI (as measured by minimum clinically important difference [MCID] for ODI/NDI) decreases.nnnRESULTSnA total of 276 patients with complete 12-month follow-up following ESI were analyzed. The mean pre-injection daily morphine equivalent amount (MEA) was 14.7u2009mg (95% confidence interval [CI] 12.4u2009mg-19.1u2009mg) for the cohort. Pre-injection opioid use was associated with slightly higher odds of worse disability (odds ratio [OR] 1.03, p=.03) and leg/arm pain (OR 1.01, p=.04) scores at 3 months post-injection only. No significant association between pre-injection opioid use and MCID for ODI/NDI was found, although a cutoff of 55.5u2009mg/day might serve as a significant threshold.nnnCONCLUSIONnIncreased pre-injection opioid use does not impact long-term outcomes after ESIs for degenerative spine diseases. A pre-injection MEA around 50u2009mg/day may represent a threshold above which the 3-month effectiveness of ESI for back- and neck-related disability decreases. Epidural steroid injection is an effective treatment modality for pain in patients using opioids, and can be part of a multimodal strategy for opioid independence.

The Challenges of Research on Interventions for Low Back Pain

Nguyen and colleagues report a randomized trial of glucocorticoid intradiscal injection for patients with chronic low back pain associated with active discopathy (1). The authors are to be commended for avoiding a common error in studies of pain: the use of mean (or average) outcomes in populations in which pain does not have a normal distribution. Instead, the researchers followed the National Institutes of Health recommendations (2) and reported categorical outcomes to appropriately account for responders and nonresponders. With respect to the primary outcome, patients who received glucocorticoid intradiscal injection were more likely than those in the control group to achieve a pain score less than 40 on a numerical rating scale at 1 month. Despite this favorable finding, the authors tempered their conclusions, noting the lack of sustained benefit at 12 months in a secondary analysis. Several key factors must be considered when interpreting these results. Research on low back pain is complicated by the heterogeneity of patients and pathologies that are represented by this common symptom. By enrolling only patients with acute Modic 1 changes, Nguyen and colleagues attempted to isolate low back pain specifically associated with inflammation to test a treatment with a plausible anti-inflammatory effect. Changes in the hypothalamic pituitary access can be seen up to 21 days after spinal injection, so the expected time course for the physiologic effect of corticosteroids is weeks (3). The positive finding at 4 weeks suggests that the authors appropriately defined categorical success rates of a specific treatment in a homogeneous population at an appropriate duration of follow-up. It is possible that even more rigorous inclusion criteria would have led to different findings. For example, all participants in the study underwent discography, a diagnostic test for disc pain, but outcomes were not reported in subgroups of patients with different discography results. The effectiveness of injection could have differed with discography findings. However, further limiting of eligibility criteria may have been infeasible, given that it took 4 years at 3 sites to enroll patients with Modic 1 changes on magnetic resonance imaging without further culling based on the results of discography. This illustrates the challenge of low back pain research: Although the condition is ubiquitous, its causes are heterogeneous. Disease heterogeneity may explain the lack of benefit of glucocorticoid injection at 12 months. Although the trial enrolled only persons with acute inflammation indicated by Modic 1 changes (4), all participants also had chronic pain. Therefore, some participants may have had more than 1 cause of pain. In some patients, chronic low back pain is not due solely to a musculoskeletal pathology. A large volume of research shows that depression, psychological distress, passive coping strategies, fear-avoidance beliefs, perceived risks of persistent low back pain, and even low educational level are linked with poor outcomes in patients presenting with low back pain (5, 6). The study population exhibited many of these characteristics: Average pain duration was 6 years; roughly half of the participants had a high school education or less; about half were unemployed; and measures of anxiety, depression, fear-avoidance beliefs, and coping strategies were unfavorable (1). It may be that glucocorticoid injection is an effective treatment for the acute inflammatory component of low back pain but fails to address the other contributors to chronic pain; Nguyen and colleagues found short-term improvement in acute pain but persistence of chronic pain. Low back pain clearly has numerous causes, and many of these causes have a favorable natural history. Thus, most patients with acute or subacute pain improve over time, regardless of therapy (7). Unfortunately, some patients progress to chronic low back pain, a leading cause of disability worldwide according to the World Health Organization (8). Although some causes of low back pain may not have a favorable natural history, secondary factors are associated with chronic pain regardless of spinal pathology. The challenge of treating chronic low back pain is reflected in recent American College of Physicians guidelines that found that most noninvasive treatment options have little or no effect (7). How should clinicians apply the results of this study? In patients with an acute pain episode that coincides with Modic 1 changes on magnetic resonance imaging, glucocorticoid intradiscal injection may be an option for short-term pain relief. However, in patients with chronic pain, glucocorticoid injection clearly is not effective over the long term. The question then arises about the utility of using an invasive treatment for short-term relief in the setting of an acute condition with a favorable natural history or for an acute flare of a chronic condition. The strengths of this study include evaluation of a specific treatment for a specific cause of low back pain. Unfortunately, much low back pain research inappropriately examines mean outcomes in a heterogeneous group of patients receiving heterogeneous treatments (9). We believe that more granularity is required to determine which treatment is right for which patients (10). Nguyen and colleagues have made progress in this regard, but more work is required.