Tools
Epidural Steroids
Introduction
Epidural steroids injections (ESI) have been utilized for the treatment of pain due to lumbar disc injuries since the 1950s.[1][2][3] They are frequently used in the treatment of radicular pain, which is a neuropathic pain syndrome, along with the sensory distribution of a dermatome of one or more spinal nerves. Typically, the pain is due to nerve root irritation from mechanical compression by an intervertebral herniated disc and resultant inflammation. Additional etiologies leading to mechanical spinal nerve compression include spondylosis, spondylolisthesis, and ligamentum flavum hypertrophy resulting in neuroforaminal stenosis. In persons with lumbosacral radiculopathy, more than half of the patients report interference in their activities of daily living, and a quarter continues to have severe pain that does not respond well to oral pharmacological treatments.[4][5][6][7]
Approximately 14% of patients with lumbosacral radiculopathy will eventually require surgery for severe pain that may or may not be associated with neurological deficit.[8] However, in many cases, radicular pain secondary to intervertebral disc herniation improves with medical and rehabilitative treatment. Steroid injection into the epidural space is used to achieve inflammation reduction and pain relief and limit medications or surgery.
The 3 routes for epidural steroid delivery include the transforaminal, interlaminar, and caudal approach. Utilization of fluoroscopy or, less commonly, computed-tomography (CT) guidance to ensure needle placement in the proper position using contrast flow has become the standard of care.[9] The efficacy of epidural steroid injections in lumbosacral radiculopathy has been widely studied, and based on a recent systematic review that included 8 randomized controlled trials, and there is a strong recommendation based on moderate-quality evidence that transforaminal ESIs can be used to reduce pain at 3 months. However, a clear improvement in physical disability and reduction in surgery was not consistently seen in the literature.[4]
Cervical ESIs similarly have been shown to provide effective short-term relief for radicular cervical pain, but long-term outcomes have not been well studied. There is limited high-quality evidence that cervical ESIs can provide benefits in radiculitis secondary to disc herniation and discogenic pain.[10] Most of the literature focuses on interlaminar cervical ESI as opposed to transforaminal cervical ESI.[11] Though rare, the morbidity associated with ESIs can be catastrophic.
Etiology
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Etiology
Common causes of nerve root compression treated with ESIs are an intervertebral herniated disc, spondylosis, spondylolisthesis, and ligamentum flavum hypertrophy which can result in neuroforaminal stenosis.
Epidemiology
Cervical pain is the fourth leading cause of disability in the United States.[12] The incidence of cervical radiculopathy is 1 in 1000 adults per year.[13][14] The rate of cervicothoracic ESIs has increased substantially over the past decade, with state-to-state utilization varying from 5 to 40 per 1000 Medicare enrollees.[15] Low back pain ranks fifth among reasons for seeking medical care in the United States[15] at an economic cost of 100 million to 50 billion dollars.[16][17][18] It is estimated that 40% of patients presenting with low back pain have associated lumbosacral radicular pain.[19][6] Estimates of the annual prevalence of low back pain with radicular symptoms described as pain coming from the back traveling below the knee varied from 9.9% to 25%.[14]
Pathophysiology
Radicular pain is theorized to result from mechanical nerve compression leading to the production of inflammatory molecules and neurochemical mediators. In intervertebral disc herniations, these mediators include phospholipase A2, substance P, vasoactive intestinal peptide, and calcitonin gene-related peptide, which are released from the nucleus pulposus. These molecules have a role in sensitizing the free nerve endings, nerve root, and dorsal root ganglion, precipitating neuropathic pain. Their presence may additionally produce changes in the ion functioning of sensory neurons that increase pain.[9][20] Delivery of corticosteroids to the site of inflammation is hypothesized to interrupt this inflammatory cascade.
Treatment / Management
Safe Triangle
Also known as subpedicular or supraneural, the safe triangle is formed by the inferior margin of the pedicle (superiorly), a line drawn inferiorly from the anterior margin of the pedicle (anteriorly), and the exiting nerve (as the hypotenuse). The traditional needle target for a transforaminal approach is the epidural space just caudal to the inferior margin of the pedicle, referred to as the 6 o'clock position. Positioning more medially increases the risk of dural puncture, and placement too laterally will not achieve retrograde epidural flow demonstrated with contrast injection. It will only perform achieve selective nerve root block. This approach was initially described as a method to theoretically minimize the risk of nerve injury, intrathecal puncture, or vascular injection.[21] Recent literature has questioned the safety of this technique due to the positioning of radiculomedullary arteries in the anterosuperior portion of the foramen and the reported cases of paraplegia associated with this technique.
Posterolateral Approach
This approach is also referred to as the modified, safe triangle approach with the tip in the posterior portion of the neural foramen and slightly inferior to the safe triangle needle position.[22] The lateral oblique fluoroscopy view targets the same safe triangle view; however, the needle is not advanced into the anterior epidural space. Instead, the tip remains in the posterior aspect of the foramen on the lateral view. This approach can be useful in cases of severe foraminal stenosis or if the patient has nerve pain during the procedure and the anterior epidural space cannot be accessed. A single-center prospective study of 50 patients showed less nerve pain with the posterolateral approach compared to the safe triangle approach with no differences in outcome measures.[23]
Kambin Triangle
The triangle is bounded by the superior endplate or the inferior vertebral body (inferiorly), the exiting nerve (hypotenuse), and by the superior articulating process (posteriorly). Initially, this technique was described as a safe and convenient method to perform discectomy and discograms.[24][25][24] The target is the inferior third of the neural foramen at the level of the intervertebral disc.[26] If the needle is advanced overly far ventrally during epidural injection, it may be inserted inadvertently into the disc. Avoiding advancing the needle medial to the mid-pedicular line reduces the risk of intradural puncture. Several studies, including a single-center prospective study, have found that the Kambin approach reduces the risk of intravascular injections compared to the safe triangle; however, the rate of intradiscal injections is higher.[27][28][29](A1)
Interlaminar Approach
The interlaminar approach can be preferable to the transforaminal approach in cases of severe neuroforaminal stenosis or in the cervical spine where the risk of intravascular injection is higher and the consequences severe. The patient is typically positioned prone. Sedation is restricted to cases of severe anxiety to allow the patient to alarm the physician in cases of pain or paresthesias, which can be a warning of a malpositioned needle. The segmental level is identified in the AP view. After appropriate local anesthesia, an 18- to 22-gauge Tuohy needle is introduced using a paramedian approach targeting the superior lamina of the lower vertebra in the segment. A loss of resistance syringe containing air, saline, or contrast is used while advancing the needle tip millimeters at a time until the loss of resistance is felt, signaling penetration through the ligamentum flavum into the epidural space. A lateral view then confirms the depth of insertion.
The obvious risk in this approach is the advancement of the needle too far anterior, puncturing the dura, or damaging the cord directly. This may also introduce the possible complication of an epidural hematoma or abscess, which may compress the cord. When possible, avoiding sedation allows the patient to alarm the physician of pain or paresthesias from needle advancement into the cord. The epidural space is narrow in the cervical spine compared to the lumbar spine and continues to narrow significantly in the "cervicogenic bulge." Therefore interlaminar injections are preferentially performed below C6, which can be sufficient for pathology above the level due to the cephalo-caudal spread of medication of about 2 levels.
Differential Diagnosis
- Lumbar compression fracture
- Lumbar degenerative disk disease
- Lumbar facet arthropathy
- Lumbar spondylolysis and spondylolisthesis
- Mechanical low back pain
- Physical medicine and rehabilitation for myofascial pain
- Rehabilitation for osteoarthritis
- Rheumatoid arthritis
- Spondylolisthesis imaging
Prognosis
The primary role of ESIs is to treat cervical or lumbosacral radicular pain, and in certain cases, bypass the need for operative intervention. Previous investigations into the efficacy of ESIs, including case series, retrospective studies, prospective clinical trials, and systematic reviews, have limitations, including heterogeneous methods and broad inclusion criteria. Published reviews often include a variety of ESI delivery routes, including transforaminal, interlaminar, and caudal, and also include a wide variety of indications in addition to radicular pain, such as axial back pain, failed back syndrome, and spinal stenosis.
Recent studies, including several reviews and meta-analyses, have shown that transforaminal and interlaminar epidural steroid injections can provide reliable pain relief for patients with low back pain associated with radicular symptoms, but not axial back pain.[30][31][32][33] In some cases, ESIs can provide long-term benefits lasting up to 12 months and surgery sparing effects.[34][35][36] For radicular pain secondary to disc herniation, the evidence is good with steroids combined with local anesthetics and fair with local anesthetics alone.[37] Theoretically, the transforaminal route is superior to interlaminar and caudal approaches in delivering medication in proximity to the exiting spinal nerve, anterior epidural space, and dorsal root ganglion.[33][38] However, comparing the transforaminal versus interlaminar approach demonstrates similar efficacy at 6 months but an early benefit at 2 weeks for transforaminal.[39][30] Other studies have shown that interlaminar ESI for primarily axial pain regardless of etiology lacks effect, except for possibly short-term pain relief.[40] Literature reviews investigating the dose of steroids in ESIs do not show a dose-dependence in analgesic effect in chronic low back pain or lumbosacral radicular pain.[41][42]
The studies for cervical ESIs have similarly heterogeneous methods and outcome measures. There is more evidence for interlaminar cervical ESIs than for transforaminal. The evidence demonstrates durable pain relief and improved disability measures at 12 to 24 months. Several of these studies required multiple injections, and there was similar efficacy between the epidural steroid injection with local anesthetic versus local anesthetic alone. The indications included radicular pain, disk herniation, cervical spinal stenosis, and cervical post-surgery syndrome.[11]
Complications
Major procedure-related complications and drug-related systemic effects of ESI requiring hospitalization including spine infection, hematoma, and sepsis are very rare. This was estimated to be 0.46% in a large single-center European study.[43] Though the incidence of permanent neurological complications from epidural steroid injections is rare, great care is taken to avoid critical vascular and neurological structures in the vicinity of the needle during injection.[44][45] Precautions to avoid an intra-arterial injection into the radicular arteries supplying the spinal cord include aspiration before injection, visualization of contrast flow, and digital subtraction angiography, and an anesthetic test dose.[45]
Particulate steroids have been implicated in multiple case reports of permanent neurological damage after cervical transforaminal ESI.[46][47][48][49][50] Intra-articular injection of steroid into a radiculomedullary artery supplying the spinal cord can cause occlusion of the anterior spinal artery and subsequent cord infarction and injection into the vertebral arteries have been known to cause posterior circulation stroke.[51][52][53] Ultrasound has been used to demonstrate the incidence of perineural blood vessels in the projected pathway for selective nerve roots blocks of C5 to C7, ranging from 5.5% to 13.5%.[53] When members of the American Pain Society were given a survey, 287/1340 physicians responded and reported 78 complications of transforaminal cervical ESI which included 16 vertebrobasilar brain infarcts, 12 cervical spinal cord infarcts, and 2 combined brain/spinal cord infarction, and 13 patients died. There are at least 18 cases of paralysis in the literature following TFESI in the lumbar spine from T12-SI despite the use of CT and fluoroscopic guidance.[54]
Different approaches have been described to safely deliver medication to the target area with avoidance of the neurovascular structures. There is controversy on the safest approach to minimize the chance of neurological injury. In a review of 18 cases of paralysis following lumbar transforaminal ESI where needle position could be determined, the needle was in the superior portion of the neural foramen in 77.7% of cases, in the mid-zone in 22.2%, and in no case was the needle in the inferior portion of the neural foramen. The needle was more commonly anterior (71.4%) and less commonly posterior (28.5%).[21] Confirmation of the needle tip is provided by contrast injection that will produce a epidurogram. If the needle tip is not placed far enough within the foramen then epidural flow may not be obtained. In this case, only the nerve is outlined and referred to as a selective nerve block.
Deterrence and Patient Education
Epidural steroid injections can be safely injected 3-4 times per year, with a minimum duration of at least two weeks. between two injections Often, two to three injections need to be done to effectively alleviate the pain. If the injections are not providing significant relief, a discussion with the healthcare provider is warranted to discuss further treatment options.
Side effects may include pain at the injection site, irritability, insomnia, increased blood sugar, edema or leg swelling, facial flushing with the sensation of warmth and redness about the face and chest, skin discoloration at the injection site.
Patients are advised to get urgent medical care if they develop a high-grade fever, severe headache with nausea/vomiting, loss of control of bowel or bladder function, or new onset of numbness, tingling, or weakness
Pearls and Other Issues
Anatomy
In the spinal column, the neural foramen is bounded anteriorly by the intervertebral disc, the superior and the inferior endplates of the vertebral bodies; posteriorly by the superior and inferior articular processes, IAP, which articulate as the facet joint; the adjacent pedicles form the roof and floor at that level. The dorsal and ventral roots join to form a spinal nerve within the neuroforamen. Each spinal nerve divides into a ventral ramus and smaller dorsal ramus as it exits the foramen.
The neuroforamen also contains arteries, veins, and epidural fat. The spinal nerves are supplied in a segmental manner by radicular arteries, which travel with each nerve root. In the thoracic and lumbar spine, radicular arteries arise from branches of the aorta and intercostal arteries. The intercostal and lumbar arteries divide into a dorsal segment supplying the paraspinal muscles, a somatic branch that travels ventral to the spinal cord that feeds the dura, and a radicular artery that supplies the spinal nerve and nerve roots within the neural foramen. The ascending cervical, deep cervical, and vertebral arteries give rise to the radicular and spinal medullary arteries, which traverse the cervical neuroforamina.
A major concern during transforaminal epidural steroid injections is careful avoidance of the radicular arteries. Specific needle approaches and protocols are designed to minimize and detect an intravascular injection discussed in the section "Complications/Safety." The largest radiculomedullary artery is the artery of Adamkiewicz, which anastomoses with the anterior spinal artery and supplies the thoracolumbar spinal cord in adults. The origin of this artery is variable but generally takes off at T9 but can arise as low as L5. It is left-sided in 68% to 85% of cases and lies in the superior or mid-portion of the neuroforamen in the majority of cases.[55][56][57] The vertebral arteries course between the transverse foramina of the C2 to C6 vertebrae, typically anterior to the cervical facet joints and the ventral ramus of the cervical nerve root though variations exist.[58]
Choice of Steroid
Previously particulate steroids (triamcinolone, methylprednisolone, and betamethasone acetate) have been favored by some providers due to their theorized "depot effect," or increasing the duration the medication is deposited at the site of pathology. The same particulate effect that theoretically provides an analgesic benefit poses a safety concern as the particulates can aggregate to form particles larger than the size of a red blood cell (RBC). This is in contrast to non-particulate steroids like dexamethasone, which are 10-fold smaller than an RBC and do not aggregate under light microscopy.[59]
Animal studies show that intravascular injection into the vertebral artery of particulate steroids cause neurological injury, whereas non-particulate steroids do not.[48] Furthermore, the theoretical analgesic advantage of particulate steroids has not been established in the literature regarding pain reduction or functional outcomes.[60][61][62][63][64][65][66] Perhaps, for this reason, non-particulate steroids are increasingly favored in transforaminal ESIs.[67][68][69][70]
Enhancing Healthcare Team Outcomes
Improving the outcomes of epidural steroid injections in the treatment of acute or chronic pain requires careful patient selection. ESIs are efficacious in the treatment of radicular pain and not axial pain. Physicians have an ethical responsibility to utilize ESIs in cases of radicular pain with a history and physical exam findings concordant with MRI evidence of nerve root pathology at the level to be treated. The evidence is lacking for ESIs in the treatment of axial back pain. Most patients with back pain, including those with disc herniation with radicular pain, will improve with time or conservative treatments, including oral analgesics, various treatment modalities, and physical therapy. Thus, it is the role of the provider to place ESIs in the context of the individual's disease and form a patient-centered treatment plan.
References
Epstein NE. Major risks and complications of cervical epidural steroid injections: An updated review. Surgical neurology international. 2018:9():86. doi: 10.4103/sni.sni_85_18. Epub 2018 Apr 23 [PubMed PMID: 29740507]
Schneider BJ, Maybin S, Sturos E. Safety and Complications of Cervical Epidural Steroid Injections. Physical medicine and rehabilitation clinics of North America. 2018 Feb:29(1):155-169. doi: 10.1016/j.pmr.2017.08.012. Epub 2017 Oct 7 [PubMed PMID: 29173660]
Rivera CE. Lumbar Epidural Steroid Injections. Physical medicine and rehabilitation clinics of North America. 2018 Feb:29(1):73-92. doi: 10.1016/j.pmr.2017.08.007. Epub [PubMed PMID: 29173666]
Bhatia A, Flamer D, Shah PS, Cohen SP. Transforaminal Epidural Steroid Injections for Treating Lumbosacral Radicular Pain from Herniated Intervertebral Discs: A Systematic Review and Meta-Analysis. Anesthesia and analgesia. 2016 Mar:122(3):857-870. doi: 10.1213/ANE.0000000000001155. Epub [PubMed PMID: 26891397]
Level 1 (high-level) evidenceHeliövaara M, Knekt P, Aromaa A. Incidence and risk factors of herniated lumbar intervertebral disc or sciatica leading to hospitalization. Journal of chronic diseases. 1987:40(3):251-8 [PubMed PMID: 3818881]
Ropper AH, Zafonte RD. Sciatica. The New England journal of medicine. 2015 Mar 26:372(13):1240-8. doi: 10.1056/NEJMra1410151. Epub [PubMed PMID: 25806916]
Weber H. The natural history of disc herniation and the influence of intervention. Spine. 1994 Oct 1:19(19):2234-8; discussion 2233 [PubMed PMID: 7809761]
Weinstein JN, Lurie JD, Tosteson TD, Tosteson AN, Blood EA, Abdu WA, Herkowitz H, Hilibrand A, Albert T, Fischgrund J. Surgical versus nonoperative treatment for lumbar disc herniation: four-year results for the Spine Patient Outcomes Research Trial (SPORT). Spine. 2008 Dec 1:33(25):2789-800. doi: 10.1097/BRS.0b013e31818ed8f4. Epub [PubMed PMID: 19018250]
Level 2 (mid-level) evidenceBogduk N. On the definitions and physiology of back pain, referred pain, and radicular pain. Pain. 2009 Dec 15:147(1-3):17-9. doi: 10.1016/j.pain.2009.08.020. Epub 2009 Sep 16 [PubMed PMID: 19762151]
Manchikanti L, Nampiaparampil DE, Candido KD, Bakshi S, Grider JS, Falco FJ, Sehgal N, Hirsch JA. Do cervical epidural injections provide long-term relief in neck and upper extremity pain? A systematic review. Pain physician. 2015 Jan-Feb:18(1):39-60 [PubMed PMID: 25675059]
Level 1 (high-level) evidenceHouse LM, Barrette K, Mattie R, McCormick ZL. Cervical Epidural Steroid Injection: Techniques and Evidence. Physical medicine and rehabilitation clinics of North America. 2018 Feb:29(1):1-17. doi: 10.1016/j.pmr.2017.08.001. Epub 2017 Oct 16 [PubMed PMID: 29173656]
Cohen SP. Epidemiology, diagnosis, and treatment of neck pain. Mayo Clinic proceedings. 2015 Feb:90(2):284-99. doi: 10.1016/j.mayocp.2014.09.008. Epub [PubMed PMID: 25659245]
Konstantinou K, Hider SL, Jordan JL, Lewis M, Dunn KM, Hay EM. The impact of low back-related leg pain on outcomes as compared with low back pain alone: a systematic review of the literature. The Clinical journal of pain. 2013 Jul:29(7):644-54. doi: 10.1097/AJP.0b013e31826f9a52. Epub [PubMed PMID: 23328336]
Level 1 (high-level) evidenceVan Boxem K, Cheng J, Patijn J, van Kleef M, Lataster A, Mekhail N, Van Zundert J. 11. Lumbosacral radicular pain. Pain practice : the official journal of World Institute of Pain. 2010 Jul-Aug:10(4):339-58. doi: 10.1111/j.1533-2500.2010.00370.x. Epub 2010 May 17 [PubMed PMID: 20492580]
Waterman BR, Belmont PJ Jr, Schoenfeld AJ. Low back pain in the United States: incidence and risk factors for presentation in the emergency setting. The spine journal : official journal of the North American Spine Society. 2012 Jan:12(1):63-70. doi: 10.1016/j.spinee.2011.09.002. Epub 2011 Oct 5 [PubMed PMID: 21978519]
Level 2 (mid-level) evidenceMcLain RF, Kapural L, Mekhail NA. Epidural steroids for back and leg pain: mechanism of action and efficacy. Cleveland Clinic journal of medicine. 2004 Dec:71(12):961-70 [PubMed PMID: 15641524]
Frymoyer JW. Back pain and sciatica. The New England journal of medicine. 1988 Feb 4:318(5):291-300 [PubMed PMID: 2961994]
Juniper M, Le TK, Mladsi D. The epidemiology, economic burden, and pharmacological treatment of chronic low back pain in France, Germany, Italy, Spain and the UK: a literature-based review. Expert opinion on pharmacotherapy. 2009 Nov:10(16):2581-92. doi: 10.1517/14656560903304063. Epub [PubMed PMID: 19874246]
Level 3 (low-level) evidenceCohen SP, Bicket MC, Jamison D, Wilkinson I, Rathmell JP. Epidural steroids: a comprehensive, evidence-based review. Regional anesthesia and pain medicine. 2013 May-Jun:38(3):175-200. doi: 10.1097/AAP.0b013e31828ea086. Epub [PubMed PMID: 23598728]
Brisby H. Pathology and possible mechanisms of nervous system response to disc degeneration. The Journal of bone and joint surgery. American volume. 2006 Apr:88 Suppl 2():68-71 [PubMed PMID: 16595447]
Mandell JC, Czuczman GJ, Gaviola GC, Ghazikhanian V, Cho CH. The Lumbar Neural Foramen and Transforaminal Epidural Steroid Injections: An Anatomic Review With Key Safety Considerations in Planning the Percutaneous Approach. AJR. American journal of roentgenology. 2017 Jul:209(1):W26-W35. doi: 10.2214/AJR.16.17471. Epub 2017 May 15 [PubMed PMID: 28504548]
Lee IS, Kim SH, Lee JW, Hong SH, Choi JY, Kang HS, Song JW, Kwon AK. Comparison of the temporary diagnostic relief of transforaminal epidural steroid injection approaches: conventional versus posterolateral technique. AJNR. American journal of neuroradiology. 2007 Feb:28(2):204-8 [PubMed PMID: 17296980]
Park JW, Nam HS, Park Y. Usefulness of posterolateral transforaminal approach in lumbar radicular pain. Annals of rehabilitation medicine. 2011 Jun:35(3):395-404. doi: 10.5535/arm.2011.35.3.395. Epub 2011 Jun 30 [PubMed PMID: 22506150]
Alamin T, Malek F, Carragee E, Kim MJ. The functional anaesthetic discogram: description of a novel diagnostic technique and report of 3 cases. SAS journal. 2008:2(2):107-13. doi: 10.1016/SASJ-2007-0123-NT. Epub 2008 Jun 1 [PubMed PMID: 25802610]
Level 3 (low-level) evidenceSimon JI, McAuliffe M, Parekh NN, Petrolla J, Furman MB. Intravascular Penetration Following Lumbar Transforaminal Epidural Injections Using the Infraneural Technique. Pain medicine (Malden, Mass.). 2015 Aug:16(8):1647-9. doi: 10.1111/pme.12754. Epub 2015 Apr 27 [PubMed PMID: 25917778]
Trinh KH, Gharibo CG, Aydin SM. Inadvertent Intradiscal Injection with TFESI Utilizing Kambin's Retrodiscal Approach in the Treatment of Acute Lumbar Radiculopathy. Pain practice : the official journal of World Institute of Pain. 2016 Apr:16(4):E70-3. doi: 10.1111/papr.12420. Epub 2016 Feb 20 [PubMed PMID: 26896050]
El-Yahchouchi CA, Plastaras CT, Maus TP, Carr CM, McCormick ZL, Geske JR, Smuck M, Pingree MJ, Kennedy DJ. Adverse Event Rates Associated with Transforaminal and Interlaminar Epidural Steroid Injections: A Multi-Institutional Study. Pain medicine (Malden, Mass.). 2016 Feb:17(2):239-49 [PubMed PMID: 26593277]
Furman MB, O'Brien EM, Zgleszewski TM. Incidence of intravascular penetration in transforaminal lumbosacral epidural steroid injections. Spine. 2000 Oct 15:25(20):2628-32 [PubMed PMID: 11034648]
Park KD, Lee J, Jee H, Park Y. Kambin triangle versus the supraneural approach for the treatment of lumbar radicular pain. American journal of physical medicine & rehabilitation. 2012 Dec:91(12):1039-50. doi: 10.1097/PHM.0b013e318264573a. Epub [PubMed PMID: 22854909]
Level 1 (high-level) evidenceLanda J, Kim Y. Outcomes of interlaminar and transforminal spinal injections. Bulletin of the NYU hospital for joint diseases. 2012:70(1):6-10 [PubMed PMID: 22894690]
Ökmen K, Ökmen BM. The efficacy of interlaminar epidural steroid administration in multilevel intervertebral disc disease with chronic low back pain: a randomized, blinded, prospective study. The spine journal : official journal of the North American Spine Society. 2017 Feb:17(2):168-174. doi: 10.1016/j.spinee.2016.08.024. Epub 2016 Aug 20 [PubMed PMID: 27555486]
Level 1 (high-level) evidenceSharma AK, Vorobeychik Y, Wasserman R, Jameson J, Moradian M, Duszynski B, Kennedy DJ, Standards Division of the Spine Intervention Society. The Effectiveness and Risks of Fluoroscopically Guided Lumbar Interlaminar Epidural Steroid Injections: A Systematic Review with Comprehensive Analysis of the Published Data. Pain medicine (Malden, Mass.). 2017 Feb 1:18(2):239-251. doi: 10.1093/pm/pnw131. Epub [PubMed PMID: 28204730]
Level 1 (high-level) evidenceBicket MC, Horowitz JM, Benzon HT, Cohen SP. Epidural injections in prevention of surgery for spinal pain: systematic review and meta-analysis of randomized controlled trials. The spine journal : official journal of the North American Spine Society. 2015 Feb 1:15(2):348-62. doi: 10.1016/j.spinee.2014.10.011. Epub 2014 Oct 13 [PubMed PMID: 25463400]
Level 1 (high-level) evidenceMacVicar 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 medicine (Malden, Mass.). 2013 Jan:14(1):14-28. doi: 10.1111/j.1526-4637.2012.01508.x. Epub 2012 Oct 30 [PubMed PMID: 23110347]
Level 1 (high-level) evidenceQuraishi NA. Transforaminal injection of corticosteroids for lumbar radiculopathy: systematic review and meta-analysis. European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society. 2012 Feb:21(2):214-9. doi: 10.1007/s00586-011-2008-y. Epub 2011 Sep 4 [PubMed PMID: 21892774]
Level 1 (high-level) evidenceBuenaventura RM, Datta S, Abdi S, Smith HS. Systematic review of therapeutic lumbar transforaminal epidural steroid injections. Pain physician. 2009 Jan-Feb:12(1):233-51 [PubMed PMID: 19165306]
Level 1 (high-level) evidenceBenyamin 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 Jul-Aug:15(4):E363-404 [PubMed PMID: 22828691]
Level 1 (high-level) evidenceManchikanti L, Knezevic NN, Boswell MV, Kaye AD, Hirsch JA. Epidural Injections for Lumbar Radiculopathy and Spinal Stenosis: A Comparative Systematic Review and Meta-Analysis. Pain physician. 2016 Mar:19(3):E365-410 [PubMed PMID: 27008296]
Level 2 (mid-level) evidenceChang-Chien GC, Knezevic NN, McCormick Z, Chu SK, Trescot AM, Candido KD. Transforaminal versus interlaminar approaches to epidural steroid injections: a systematic review of comparative studies for lumbosacral radicular pain. Pain physician. 2014 Jul-Aug:17(4):E509-24 [PubMed PMID: 25054401]
Level 1 (high-level) evidenceDePalma MJ, Slipman CW. Evidence-informed management of chronic low back pain with epidural steroid injections. The spine journal : official journal of the North American Spine Society. 2008 Jan-Feb:8(1):45-55. doi: 10.1016/j.spinee.2007.09.009. Epub [PubMed PMID: 18164453]
Level 1 (high-level) evidenceWhynes DK, McCahon RA, Ravenscroft A, Hardman J. Cost effectiveness of epidural steroid injections to manage chronic lower back pain. BMC anesthesiology. 2012 Sep 27:12():26. doi: 10.1186/1471-2253-12-26. Epub 2012 Sep 27 [PubMed PMID: 23016755]
Owlia MB, Salimzadeh A, Alishiri G, Haghighi A. Comparison of two doses of corticosteroid in epidural steroid injection for lumbar radicular pain. Singapore medical journal. 2007 Mar:48(3):241-5 [PubMed PMID: 17342295]
Level 1 (high-level) evidenceLee JW, Lee E, Lee GY, Kang Y, Ahn JM, Kang HS. Epidural steroid injection-related events requiring hospitalisation or emergency room visits among 52,935 procedures performed at a single centre. European radiology. 2018 Jan:28(1):418-427. doi: 10.1007/s00330-017-4977-7. Epub 2017 Jul 19 [PubMed PMID: 28726118]
Carr CM, Plastaras CT, Pingree MJ, Smuck M, Maus TP, Geske JR, El-Yahchouchi CA, McCormick ZL, Kennedy DJ. Immediate Adverse Events in Interventional Pain Procedures: A Multi-Institutional Study. Pain medicine (Malden, Mass.). 2016 Dec:17(12):2155-2161. doi: 10.1093/pm/pnw051. Epub 2016 Apr 15 [PubMed PMID: 28025351]
Chang Chien GC, Candido KD, Knezevic NN. Digital subtraction angiography does not reliably prevent paraplegia associated with lumbar transforaminal epidural steroid injection. Pain physician. 2012 Nov-Dec:15(6):515-23 [PubMed PMID: 23159970]
Level 3 (low-level) evidenceBose B. Quadriparesis following cervical epidural steroid injections: case report and review of the literature. The spine journal : official journal of the North American Spine Society. 2005 Sep-Oct:5(5):558-63 [PubMed PMID: 16153586]
Level 3 (low-level) evidenceKennedy DJ, Dreyfuss P, Aprill CN, Bogduk N. Paraplegia following image-guided transforaminal lumbar spine epidural steroid injection: two case reports. Pain medicine (Malden, Mass.). 2009 Nov:10(8):1389-94. doi: 10.1111/j.1526-4637.2009.00728.x. Epub 2009 Oct 26 [PubMed PMID: 19863744]
Level 3 (low-level) evidenceOkubadejo GO, Talcott MR, Schmidt RE, Sharma A, Patel AA, Mackey RB, Guarino AH, Moran CJ, Riew KD. Perils of intravascular methylprednisolone injection into the vertebral artery. An animal study. The Journal of bone and joint surgery. American volume. 2008 Sep:90(9):1932-8. doi: 10.2106/JBJS.G.01182. Epub [PubMed PMID: 18762654]
Level 3 (low-level) evidenceHouten JK, Errico TJ. Paraplegia after lumbosacral nerve root block: report of three cases. The spine journal : official journal of the North American Spine Society. 2002 Jan-Feb:2(1):70-5 [PubMed PMID: 14588291]
Level 3 (low-level) evidenceHuntoon MA, Martin DP. Paralysis after transforaminal epidural injection and previous spinal surgery. Regional anesthesia and pain medicine. 2004 Sep-Oct:29(5):494-5 [PubMed PMID: 15372396]
Level 3 (low-level) evidenceNeal JM. Anatomy and pathophysiology of spinal cord injury associated with regional anesthesia and pain medicine. Regional anesthesia and pain medicine. 2008 Sep-Oct:33(5):423-34. doi: 10.1016/j.rapm.2006.10.014. Epub [PubMed PMID: 18774511]
Laemmel E, Segal N, Mirshahi M, Azzazene D, Le Marchand S, Wybier M, Vicaut E, Laredo JD. Deleterious Effects of Intra-arterial Administration of Particulate Steroids on Microvascular Perfusion in a Mouse Model. Radiology. 2016 Jun:279(3):731-40. doi: 10.1148/radiol.2015142746. Epub 2016 Jan 13 [PubMed PMID: 26761719]
Epstein NE. The risks of epidural and transforaminal steroid injections in the Spine: Commentary and a comprehensive review of the literature. Surgical neurology international. 2013:4(Suppl 2):S74-93. doi: 10.4103/2152-7806.109446. Epub 2013 Mar 22 [PubMed PMID: 23646278]
Level 3 (low-level) evidenceAtluri S, Glaser SE, Shah RV, Sudarshan G. Needle position analysis in cases of paralysis from transforaminal epidurals: consider alternative approaches to traditional technique. Pain physician. 2013 Jul-Aug:16(4):321-34 [PubMed PMID: 23877448]
Level 3 (low-level) evidenceBiglioli P, Spirito R, Roberto M, Grillo F, Cannata A, Parolari A, Maggioni M, Coggi G. The anterior spinal artery: the main arterial supply of the human spinal cord--a preliminary anatomic study. The Journal of thoracic and cardiovascular surgery. 2000 Feb:119(2):376-9 [PubMed PMID: 10649214]
Alleyne CH Jr, Cawley CM, Shengelaia GG, Barrow DL. Microsurgical anatomy of the artery of Adamkiewicz and its segmental artery. Journal of neurosurgery. 1998 Nov:89(5):791-5 [PubMed PMID: 9817417]
Kroszczynski AC, Kohan K, Kurowski M, Olson TR, Downie SA. Intraforaminal location of thoracolumbar anterior medullary arteries. Pain medicine (Malden, Mass.). 2013 Jun:14(6):808-12. doi: 10.1111/pme.12056. Epub 2013 Feb 25 [PubMed PMID: 23438301]
Hoeft MA, Rathmell JP, Monsey RD, Fonda BJ. Cervical transforaminal injection and the radicular artery: variation in anatomical location within the cervical intervertebral foramina. Regional anesthesia and pain medicine. 2006 May-Jun:31(3):270-4 [PubMed PMID: 16701194]
Derby R, Lee SH, Date ES, Lee JH, Lee CH. Size and aggregation of corticosteroids used for epidural injections. Pain medicine (Malden, Mass.). 2008 Mar:9(2):227-34. doi: 10.1111/j.1526-4637.2007.00341.x. Epub [PubMed PMID: 18298706]
Mehta P, Syrop I, Singh JR, Kirschner J. Systematic Review of the Efficacy of Particulate Versus Nonparticulate Corticosteroids in Epidural Injections. PM & R : the journal of injury, function, and rehabilitation. 2017 May:9(5):502-512. doi: 10.1016/j.pmrj.2016.11.008. Epub 2016 Nov 30 [PubMed PMID: 27915069]
Level 1 (high-level) evidenceFeeley IH, Healy EF, Noel J, Kiely PJ, Murphy TM. Particulate and non-particulate steroids in spinal epidurals: a systematic review and meta-analysis. European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society. 2017 Feb:26(2):336-344. doi: 10.1007/s00586-016-4437-0. Epub 2016 Feb 12 [PubMed PMID: 26873103]
Level 1 (high-level) evidenceMcCormick ZL, Cushman D, Marshall B, Caldwell M, Patel J, Ghannad L, Eng C, Makovitch S, Babu A, Chu SK, Marciniak C, Walega DR, Press J, Plastaras C, Kennedy DJ. Pain Reduction and Repeat Injections After Transforaminal Epidural Injection With Particulate Versus Nonparticulate Steroid for the Treatment of Chronic Painful Lumbosacral Radiculopathy. PM & R : the journal of injury, function, and rehabilitation. 2016 Nov:8(11):1039-1045. doi: 10.1016/j.pmrj.2016.03.011. Epub 2016 Apr 6 [PubMed PMID: 27060648]
El-Yahchouchi C, Geske JR, Carter RE, Diehn FE, Wald JT, Murthy NS, Kaufmann TJ, Thielen KR, Morris JM, Amrami KK, Maus TP. The noninferiority of the nonparticulate steroid dexamethasone vs the particulate steroids betamethasone and triamcinolone in lumbar transforaminal epidural steroid injections. Pain medicine (Malden, Mass.). 2013 Nov:14(11):1650-7. doi: 10.1111/pme.12214. Epub 2013 Jul 30 [PubMed PMID: 23899304]
Level 2 (mid-level) evidenceKennedy DJ, Plastaras C, Casey E, Visco CJ, Rittenberg JD, Conrad B, Sigler J, Dreyfuss P. Comparative effectiveness of lumbar transforaminal epidural steroid injections with particulate versus nonparticulate corticosteroids for lumbar radicular pain due to intervertebral disc herniation: a prospective, randomized, double-blind trial. Pain medicine (Malden, Mass.). 2014 Apr:15(4):548-55. doi: 10.1111/pme.12325. Epub 2014 Jan 2 [PubMed PMID: 24393129]
Level 1 (high-level) evidenceDenis I, Claveau G, Filiatrault M, Fugère F, Fortin L. Randomized Double-Blind Controlled Trial Comparing the Effectiveness of Lumbar Transforaminal Epidural Injections of Particulate and Nonparticulate Corticosteroids for Lumbosacral Radicular Pain. Pain medicine (Malden, Mass.). 2015 Sep:16(9):1697-708. doi: 10.1111/pme.12846. Epub 2015 Jun 22 [PubMed PMID: 26095339]
Level 1 (high-level) evidenceCollighan N, Gupta S, Richardson J, Cheema S. Re: Comparison of the effectiveness of lumbar transforaminal epidural injection with the particulate and nonparticulate corticosteroids in lumbar radiating pain. Pain medicine (Malden, Mass.). 2011 Aug:12(8):1290-1; author reply 1292. doi: 10.1111/j.1526-4637.2011.01197.x. Epub [PubMed PMID: 21848840]
Level 3 (low-level) evidenceRathmell JP, Benzon HT, Dreyfuss P, Huntoon M, Wallace M, Baker R, Riew KD, Rosenquist RW, Aprill C, Rost NS, Buvanendran A, Kreiner DS, Bogduk N, Fourney DR, Fraifeld E, Horn S, Stone J, Vorenkamp K, Lawler G, Summers J, Kloth D, O'Brien D Jr, Tutton S. Safeguards to prevent neurologic complications after epidural steroid injections: consensus opinions from a multidisciplinary working group and national organizations. Anesthesiology. 2015 May:122(5):974-84. doi: 10.1097/ALN.0000000000000614. Epub [PubMed PMID: 25668411]
Level 3 (low-level) evidenceDiehn FE, Murthy NS, Maus TP. Science to Practice: What Causes Arterial Infarction in Transforaminal Epidural Steroid Injections, and Which Steroid Is Safest? Radiology. 2016 Jun:279(3):657-9. doi: 10.1148/radiol.2016160171. Epub [PubMed PMID: 27183400]
MacMahon PJ, Huang AJ, Palmer WE. Spine Injectables: What Is the Safest Cocktail? AJR. American journal of roentgenology. 2016 Sep:207(3):526-33. doi: 10.2214/AJR.16.16379. Epub 2016 Jun 24 [PubMed PMID: 27341350]
Dietrich TJ, Sutter R, Froehlich JM, Pfirrmann CW. Particulate versus non-particulate steroids for lumbar transforaminal or interlaminar epidural steroid injections: an update. Skeletal radiology. 2015 Feb:44(2):149-55. doi: 10.1007/s00256-014-2048-6. Epub 2014 Nov 14 [PubMed PMID: 25394547]