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Table of Contents  
Year : 2017  |  Volume : 11  |  Issue : 3  |  Page : 697-701  

Impact of different approaches of epidural steroid injection on outcome of patients treated for low backache

1 Department of Anesthesia, Government Multi Specialty Hospital, Chandigarh, Punjab, India
2 Department of Anesthesia, Shri Guru Ram Das Institute of Medical Sciences and Research, Amritsar, Punjab, India
3 Department of Anesthesia, BPS Government Medical College for Women, Khanpur Kalan, Haryana, India
4 Department of Orthopaedics, Shri Guru Ram Das Institute of Medical Sciences and Research, Amritsar, Punjab, India
5 Department of Radiodiagnosis, Healthmap Diagnostics Private Limited, Sonepat, Haryana, India

Date of Web Publication10-Apr-2017

Correspondence Address:
Sukhdeep Kaur
House No. 1074, First Floor, Sector 15B, Chandigarh
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0259-1162.204205

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Objectives: The objective of this study was to evaluate the clinical efficacy of epidural steroid injections through different approaches using pain relief and improvement in functional capacity as outcome measures. Materials and Methods: Sixty patients with low backache and unilateral radiculopathy were randomly assigned to three groups of twenty patients each, for undergoing lumbar epidural steroid injection (LESI) through midline, transforaminal, and paramedian approaches under fluoroscopic guidance. All the patients were assessed at 1 week, 1 month and 3 months postintervention using visual analog scale (VAS) score, Quebec disability score, and depression score. Results: The primary and secondary outcome measured in terms of improvement of VAS showed statistically significant reduction (P < 0.05) when compared to preprocedure baseline readings on both intragroup analysis (Groups I, II and III) at 1-week, 1-month, and 3-month follow-up. However, on intergroup comparison, the difference in improvement of VAS score noted was statistically insignificant with P value of 0.07 (Group I/II), 0.19 (Group II/III), 0.85 (Group I/III) at final 3rd month follow-up. In addition, intergroup comparison for secondary outcome showed statistically insignificant improvement (P value for Quebec score 0.73 [Group I/II], 0.34 [Group II/III], 0.79 [Group I/III] and depression score 0.78 [Group I/II], 0.67 [Group II/III], 0.98 [Group I/III]) at final 3rd month follow-up. Conclusions: All three LESI approaches proved highly effective individually in terms of short-term pain relief, improvement in the quality of life, and depression; however, none proved to be better than the other.

Keywords: Depression score, lumbar epidural steroid injection, midline interlaminar, paramedian interlaminar, Quebec score, transforaminal

How to cite this article:
Kaur S, Gupta R, Singh S, Kumar R, Singh K. Impact of different approaches of epidural steroid injection on outcome of patients treated for low backache. Anesth Essays Res 2017;11:697-701

How to cite this URL:
Kaur S, Gupta R, Singh S, Kumar R, Singh K. Impact of different approaches of epidural steroid injection on outcome of patients treated for low backache. Anesth Essays Res [serial online] 2017 [cited 2020 Jun 4];11:697-701. Available from:

   Introduction Top

Low back pain is an important clinical, social, economic, and public health problem that affects 70%–80% of the human population at some point during their lifetime. The most commonly encountered cause of low back pain is a prolapsed intervertebral disc. Inflammatory activation of nociceptors in epidural space induces the release of neurochemical mediators. These mediators lead to recruitment of pain fibers that ultimately transmit pain to the spinal cord.[1]

Epidural injections have been employed in the conservative care of lumbar disc disease since 1952. Advancements in this field devised different approaches to access the epidural space, namely, the midline, interlaminar, and transforaminal (TF) lumbar epidural steroid injections (LESIs).[2] Various authors have recommended one approach over the other on the basis of better pain relief. However, none has yet fulfilled the criteria of being ideal in providing pain relief, improved function, and better quality of life (QOL). Thus, we conducted the present study in an attempt to resolve the long-standing dilemma faced by pain management interventionists about the best approach of epidural steroid injections to treat lower backache with radiculopathy. To the best of our knowledge, this is the first study comparing all three approaches directly in terms of clinical efficacy.

   Materials and Methods Top

This was a prospective, randomized, double-blinded, observational human study done over a period of 2 years (August 2009–August 2011). After attaining approval from the Ethics Committee and getting written and informed consent signed, sixty patients were selected for the study. In total, 75 patients were enrolled, among which 15 patients did not meet the inclusion criteria. In inclusion criteria, patients in the age group of 18–70 years presenting to pain clinic with chronic low back ache and unilateral leg radiculopathy of minimum 4 weeks duration and having no relief with conventional treatment were included in the study. Patients with a history of previous spinal surgery, LESI in the past year, allergy to drugs used, concurrent use of systemic steroid medications, opioid habituation, neurological deficit, and current pregnancy were excluded from the study.

A sample size of sixty patients was found adequate based on literature search to obtain the power of 0.85 with a permissible error of 0.05. Randomization was done using computer-generated random number list and assigned into three groups for LESI approach - either midline (Group I), TF (Group II), or paramedian (Group III) epidural block (n = 20 each) by author Saru Singh [Figure 1]. The study was double-blinded, in which both the patient and the physician evaluating the results (Sukhdeep Kaur) were unaware of the respective study group.
Figure 1: Consort diagram showing selection and randomization of patients

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Magnetic resonance imaging (MRI) of lumbosacral spine was done before the procedure for each patient. After registering demographic data, these patients were evaluated for pain using visual analog scale (VAS) score of 0–100. QOL was assessed using Quebec disability score and depression score. In addition, any history of previous treatment and coexisting diseases was sought.

The procedure was done in the prone position after starting intravenous line and under fluoroscopic guidance using strict asepsis by the same interventionist (Ruchi Gupta). The appropriate injection site was selected on the basis of clinical symptoms and radiological findings. Heart rate, blood pressure, and oxygen saturation were constantly monitored during the procedure. The segmental level of injection to be given was selected according to the patient symptoms and MRI findings. The entry point and side of needle entry were determined radiologically using marker needle. We started from the anteroposterior (AP) position and C-arm adjustments were done till the spinous process appeared along the midline.

Local anesthesia was given at entry point. In midline approach, a 3.5-inch Tuohy-type epidural needle was introduced at the midpoint of interlaminar space, and in the paramedian approach, it was introduced at later almost part of interlaminar space as indicated by the direct AP projection on fluoroscopy. The needle was advanced directly perpendicular to the skin in a posterior to anterior direction, with the use of the loss of resistance to air technique to identify the epidural space. The paramedian orientation of the needle was maintained throughout the procedure in paramedian approach. Once the loss of resistance was obtained, contrast media 2 ml was injected using real-time fluoroscopy after confirming the needle tip position in AP and lateral views and images were obtained in the lateral and AP projections.

For the TF approach, a 3.5-inch spinal needle with the tip slightly curved was introduced at the appropriately documented level of disc pathology using an oblique orientation of the fluoroscopy C-arm. Scotty dog image was visualized by oblique angulation of C-arm, and our target was to reach just below the neck of scotty dog. The needle was kept in the end on position, i.e., in a direction parallel to X-ray beam and was advanced until the needle tip was at the level of the intervertebral neural foramen as seen in the lateral projection. After aspiration, 1 ml of contrast was injected to assess for intravascular flash using real-time fluoroscopy, and the contrast spread in ventral epidural space was recorded. Then, another 1 ml of contrast was injected, and the dispersal pattern was recorded.

After confirming the needle position, 5 ml of epidural injection was given using bupivacaine (0.25%), triamcinolone acetate (80 mg), hyaluronidase (1500 U), and tramadol (50 mg). After the procedure, the patient was made supine and vitals were checked again. The patients were discharged on the same day after observation in the recovery room. Any complication that occurred during or after the procedure was noted and treated accordingly. One week after the procedure, all the patients underwent physiotherapy on a daily basis for 10 days.

Postinjection evaluation was done at 1 week, 1 month, and 3 months after injection. The primary outcome measure was an improvement in VAS score in each group after epidural injection at 1-week, 1-month and 3-month follow-up. The secondary outcome measure was an improvement in QOL (Quebec and depression score) at 1-week, 1-month and 3-month follow-up. The number of patients requiring repeat injections was also noted. For repeat injections, at 1-month follow-up, patient satisfaction score was recorded on a scale of 1–5 and patients with a score of ≤3 were given repeat block with the same technique. At 3-month follow-up, the patients with no substantial clinical improvement were referred for surgical intervention. The fluoroscopic patterns of the three groups were also evaluated; primary analysis of data thus obtained was correlated with the clinical improvement over the next 3 months and has been published.[3] The number of attempts required to reach the target site and complications pertaining to the procedure were also included in the primary analysis.

At the end of the study, data pertaining to QOL scores were compiled and statistically analyzed using Chi-square test for nonparametric data and Student's t-test and ANOVA test for parametric data.

   Results Top

In this prospective observational study, a total of sixty patients of chronic low backache with radiculopathy were randomly divided into three groups of twenty patients each and were given epidural injections through midline (Group I), TF (Group II), and paramedian (Group III) approaches. The demographic data (age, sex, weight, height) in all three groups were statistically comparable [Table 1]. Furthermore, there was no difference in baseline preprocedure VAS scores, Quebec scores, and depression scores.
Table 1: Demographic data and preprocedure (mean scores)

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Primary outcome

The intragroup analysis in all three approaches (Groups I, II, and III) showed statistically significant reduction (P < 0.05) in the VAS score (primary outcome) when compared to preprocedure baseline readings at 1-week, 1-month and 3-month follow-up [Table 2]. The intergroup comparison was also done recording the mean VAS scores in all the three groups at 1-week, 1-month and 3-month follow-up; however, there was statistically insignificant (P > 0.05) difference among the three groups [Table 3].
Table 2: Intragroup comparison of pain and quality of life scores

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Table 3: Intergroup comparison of pain and quality of life scores

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Secondary outcome

For secondary outcome measures, intragroup analysis in all three approaches (Groups I, II and III) showed statistically significant (P < 0.05) reduction in the Quebec and depression scores when compared to preprocedure baseline readings at 1-week, 1-month and 3-month follow-up [Table 2]. However, the intergroup comparison of mean Quebec and depression scores among the three groups at 1-week, 1-month and 3-month follow-up was statistically insignificant (P > 0.05) [Table 3].

Repeat injections [Figure 2] were highest in midline group and equivalent in TF and paramedian groups, but these results were found to be statistically insignificant (P > 0.05). Surgery was required only in one patient in paramedian group and comparison was statistically insignificant (P > 0.05). Complications reported were minor and transient. No major complications were observed in any of the three approaches.
Figure 2: Comparison of repeat blocks

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   Discussion Top

Herniation of intervertebral disc causes chronic low backache due to mechanical compression of neural structures as well as release of inflammatory mediators. Despite advances in knowledge of pathophysiology of backache, pharmacology of analgesics, and development of more effective techniques, management of lower backache still presents a challenge to pain physicians.

Epidural blockade alters or interrupts nociceptive input and the delivery of steroids near the affected inflamed nerve roots relieves pain. However, the therapeutic effect is dependent on many variables; the most important being the approach used for delivering the LESI. Each has its own pros and cons. The midline interlaminar approach under fluoroscopic guidance is relatively easy and safe, but the spread of injectate into the lateral and ventral epidural spaces may be limited due to the presence of epidural ligaments/scar tissue and thus, clinical efficacy seems to be limited.[4] The TF approach is more target-specific, requiring the smallest volume of steroid to reach posterolateral aspect of intervertebral foramen and places steroid directly adjacent to the affected spinal nerve at the site of inflammation. Although considered target-specific and efficacious, this approach is associated with several disadvantages such as intraneural injection, neural trauma, intravascular injection, and spinal cord trauma.[5],[6] The paramedian interlaminar injection performed at the lateral most part of the interlaminar space is considered even superior to TF approach for placing contrast into anterior epidural space with a reduction in fluoroscopic times and an improved spread grade.[7]

There is insufficient evidence comparing the clinical efficacy of midline interlaminar, TF, and paramedian interlaminar approaches directly. A Cochrane review of injection therapy for subacute and chronic low back pain in 2008 presented by Staal et al. considered 20% improvement in pain scores and 10% improvement in functioning outcomes to be clinically important. They concluded that there is no strong evidence for or against the use of any type of procedure; however, specific subgroups of patients may rvespond to specific types of injections.[8] Further in 2011, Rados et al. published prospective, randomized study on comparison of the efficacy of interlaminar and TF epidural steroid injection in patients with chronic unilateral radicular pain. He found similar results in both groups in terms of VAS score and Oswestry score reduction.[9]

Contrary to the above, one research group reported statistically significant improvement in visual numeric rating scale in TF group than paramedian approach.[10] The observed contrast in relation to our study can be due to the reason that our study was conducted using the same volume of drug in all the approaches, whereas the authors of the above said study used lower volumes and higher concentration of local anesthetic solution in TF as compared to interlaminar group. This may also highlight the role of physiotherapy and exercises started within 1 week of the procedure in all the groups.

Repeat blocks were administered maximally in midline group though the results were statistically insignificant. Furthermore, surgery was required only in one patient in paramedian group and comparison was statistically insignificant. Similar results have been observed by Schaufele et al. and Smith et al., where different approaches of LESI s were studied.[10],[11]

The primary analysis of this research with regard to epidurography also demonstrated midline, TF, and paramedian approaches to be statistically comparable in terms of clinical outcome (number of patients >50% pain relief), although midline and paramedian were technically easier as compared to TF approach. Moreover, the incidence of ventral spread and nerve root delineation showed a definite correlation with clinical improvement.[3]

The highlight of our study is that it is the first type of study to compare all three approaches directly. Till now, both interlaminar approaches were compared with each other or either of them was compared with TF approach. Proper blinding of the study and use of fluoroscopy were other strong points of our study. The limitations of this study include a lack of control group, small sample size, use of the same volume of drug in all the three groups, and a short follow-up period of 3 months. However, the present study is an effort to weigh the benefits and shortcomings of the presently available approaches for lumbar epidural administration.

   Conclusions Top

Intervention had led to a better outcome in patients suffering from low backache; all the three approaches resulted in improved outcome so far as pain, QOL, and depression score were concerned. However, none of the approaches proved superior over the other when compared till 3-month follow-up. The selection of technique may be subjected to individual preference and expertise of interventionist.


This article is based on the study first reported in Korean journal of anesthesia in which epidurography flow patterns were studied and were compared with clinical improvement.[3]

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Conflicts of interest

There are no conflicts of interest.

   References Top

Murphy RW. Nerve roots and spinal nerves in degenerative disk disease. Clin Orthop Relat Res 1977;129:46-60.  Back to cited text no. 1
Choi YK, Barbella JD. Evaluation of epidurographic contrast patterns with fluoroscopic-guided lumbar interlaminar ventral epidural injection. Pain Pract 2009;9:275-81.  Back to cited text no. 2
Gupta R, Singh S, Kaur S, Singh K, Aujla K. Correlation between epidurographic contrast flow patterns and clinical effectiveness in chronic lumbar discogenic radicular pain treated with epidural steroid injections via different approaches. Korean J Pain 2014;27:353-9.  Back to cited text no. 3
Rosenberg SK, Grabinsky A, Kooser C, Boswell MV. Effectiveness of transforaminal epidural steroid injections in low back pain: A one year experience. Pain Physician 2002;5:266-70.  Back to cited text no. 4
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.  Back to cited text no. 5
Buenaventura RM, Datta S, Abdi S, Smith HS. Systematic review of therapeutic lumbar transforaminal epidural steroid injections. Pain Physician 2009;12:233-51.  Back to cited text no. 6
Candido KD, Raghavendra MS, Chinthagada M, Badiee S, Trepashko DW. A prospective evaluation of iodinated contrast flow patterns with fluoroscopically guided lumbar epidural steroid injections: The lateral parasagittal interlaminar epidural approach versus the transforaminal epidural approach. Anesth Analg 2008;106:638-44.  Back to cited text no. 7
Staal JB, de Bie R, de Vet HC, Hildebrandt J, Nelemans P. Injection therapy for subacute and chronic low-back pain. Cochrane Database Syst Rev 2008;3:CD001824.  Back to cited text no. 8
Rados I, Sakic K, Fingler M, Kapural L. Efficacy of interlaminar vs. transforaminal epidural steroid injection for the treatment of chronic unilateral radicular pain: Prospective, randomized study. Pain Med 2011;12:1316-21.  Back to cited text no. 9
Schaufele MK, Hatch L, Jones W. Interlaminar versus transforaminal epidural injections for the treatment of symptomatic lumbar intervertebral disc herniations. Pain Physician 2006;9:361-6.  Back to cited text no. 10
Smith CC, Booker T, Schaufele MK, Weiss P. Interlaminar versus transforaminal epidural steroid injections for the treatment of symptomatic lumbar spinal stenosis. Pain Med 2010;11:1511-5.  Back to cited text no. 11


  [Figure 1], [Figure 2]

  [Table 1], [Table 2], [Table 3]

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