Advertisement

Treatment of lumbar spinal stenosis with epidural steroid injections: a retrospective outcome study

      Abstract

      Delport EG, Cucuzzella AR, Marley JK, Pruitt CM, Fisher JR. Treatment of lumbar spinal stenosis with epidural steroid injections: a retrospective outcome study. Arch Phys Med Rehabil 2004;85:479–84.

      Objective

      To determine patient satisfaction, relief of pain, frequency of injections, change of function, and subsequent surgical rate in patients who received epidural steroid injections (ESIs) for the diagnosis of lumbar spinal stenosis (LSS).

      Design

      Retrospective review conducted using a standard set of questions asked over the telephone, 6 to 36 months after the patient received an ESI.

      Setting

      An outpatient spine center.

      Participants

      One hundred forty patients at or over the age of 55 years diagnosed with LSS who received ESI(s).

      Intervention

      Transforaminal or caudal fluoroscopically guided ESIs with 60 to 100mg of triamcinalone in combination with local anesthetic or normal saline.

      Main outcome measures

      Duration and amount of pain relief, change in functional status, patient satisfaction, and surgical rate, assessed by a 5-item questionnaire.

      Results

      Of the 140 participants, 32% reported more than 2 months of pain relief, 39% reported less than 2 months of pain relief, and 29% reported no relief from the injection(s). Twenty percent subsequently had surgery. Fifty-three percent reported improvement in their functional abilities. Seventy-four percent where at least somewhat satisfied with ESI as a form of treatment.

      Conclusions

      ESI is a reasonable treatment for LSS, providing one third of our patient population with sustained relief and more than half with sustained improvement in function.

      Keywords

      Degenerative lumbar spinal stenosis (LSS) accounts for a substantial number of patients seeking treatment for low back and lower-extremity pain. Treatment for stenosis has historically consisted of some form of conservative treatment or, in the absence of positive results from the former, surgery. Although both surgery and more conservative treatments are pervasive, only a few outcome studies have been undertaken to evaluate the effectiveness of the various interventions.
      This scarcity of outcome studies on treatment for stenosis contributes to the existing uncertainty about what specific treatment is best and when it is most appropriate. In the Maine Lumbar Spine Study, stenosis patients reported better outcomes with surgery than with conservative management at 1 and 4 years,
      • Atlas S.J.
      • Deyo R.A.
      • Keller R.B.
      • et al.
      The Maine Lumbar Spine Study, Part III 1-year outcomes of surgical and nonsurgical management of lumbar spinal stenosis.
      ,
      • Atlas S.J.
      • Keller R.B.
      • Robson D.
      • Deyo R.A.
      • Singer D.E.
      Surgical and nonsurgical management of lumbar spinal stenosis four-year outcomes from the Maine lumbar spine study.
      although surgical outcomes declined somewhat over time, and outcomes of patients who had conservative treatments improved somewhat with time. Surgery also may be contraindicated in many stenotic patients because of significant comorbidities. Conservative management, therefore, remains a necessary and viable alternative for those who cannot or do not want to undergo surgery.
      Epidural steroid injections (ESIs) have been used since 1952 for the treatment of radicular pain and are currently being used with increasing frequency for the treatment of stenosis, particularly in the United States.
      • Robechi A.
      • Capra R.
      L’idrocortisone (composto F) Prime esperienze cliniche in campo reumatologico.
      With stenosis, mechanical compression of the nerve root(s) may result in the formation of edema as a result of microvascular injury, theoretically producing pain.
      • Rydevik B.
      • Brown M.D.
      • Lundborg G.
      Pathoanatomy and pathophysiology of nerve root compression.
      ,
      • Olmarker K.
      • Redevik B.
      • Holm S.
      Edema formation in spinal nerve roots induced by experimental, graded compression an experimental study on the pig cauda equina with special reference to differences in effects between rapid and slow onset of compression.
      It has been proposed that steroid injections may reduce pain by 1 or more of the following mechanisms: inhibiting the formation of nerve root edema,
      • Rydevik B.
      • Brown M.D.
      • Lundborg G.
      Pathoanatomy and pathophysiology of nerve root compression.
      having an anti-inflammatory effect,
      • Kantrowitz F.
      • Robinson D.R.
      • McGuire M.B.
      • Levine L.
      Corticosteroids inhibit prostaglandin production by rheumatoid synovia.
      increasing blood flow to neural elements and thus improving ischemic neuritis,
      • Fukusaki M.
      • Kobayashi I.
      • Hara T.
      • Sumikawa K.
      Symptoms of spinal stenosis do not improve after epidural steroid injection.
      or blocking conduction in nociceptive nerve fibers.
      • Johansson A.
      • Hao J.
      • Sjolund B.
      Local corticosteroid application blocks transmission in normal nociceptor C-fibres.
      Regardless of its frequent use, the ESI procedure for treatment of stenosis is controversial, and the efficacy of this treatment has not been well documented. The existing literature on ESI typically examines the procedure’s effectiveness for multiple diagnoses instead of focusing solely on its use for treatment of stenosis. Six controlled studies
      • Breivik H.
      • Hesla P.E.
      • Molnar I.
      • Lind B.
      Treatment of chronic low back pain and sciatica comparison of caudal epidural injections of bupivacaine and methylprednisolone with bupivacaine followed by saline.
      ,
      • Beliveau P.
      A comparison between epidural anesthesia with and without corticosteroids in the treatment of sciatica.
      ,
      • Bush K.
      • Hillier S.
      A controlled study of caudal epidural injections of triamcinolone plus procaine for the management of intractable sciatica.
      ,
      • Daly P.
      Caudal epidural anesthesia in lumbosciatic pain.
      ,
      • Mathews J.A.
      • Mills S.B.
      • Jenkins V.M.
      • et al.
      Back pain and sciatica controlled trials of manipulation, traction, sclerosant and epidural injections.
      ,
      • Yates D.W.
      A comparison of the types of epidural injection commonly used in the treatment of intervertebral disc herniation.
      completed since 1970 looked at the use of caudal epidurals for back and leg pain. Five
      • Breivik H.
      • Hesla P.E.
      • Molnar I.
      • Lind B.
      Treatment of chronic low back pain and sciatica comparison of caudal epidural injections of bupivacaine and methylprednisolone with bupivacaine followed by saline.
      ,
      • Bush K.
      • Hillier S.
      A controlled study of caudal epidural injections of triamcinolone plus procaine for the management of intractable sciatica.
      ,
      • Daly P.
      Caudal epidural anesthesia in lumbosciatic pain.
      ,
      • Mathews J.A.
      • Mills S.B.
      • Jenkins V.M.
      • et al.
      Back pain and sciatica controlled trials of manipulation, traction, sclerosant and epidural injections.
      ,
      • Yates D.W.
      A comparison of the types of epidural injection commonly used in the treatment of intervertebral disc herniation.
      of the 6 reported superior outcomes when comparing the use of epidural steroids with anesthetic or saline alone, but many of these studies lacked sufficient data or failed to reach statistical significance to support their conclusions.
      • Breivik H.
      • Hesla P.E.
      • Molnar I.
      • Lind B.
      Treatment of chronic low back pain and sciatica comparison of caudal epidural injections of bupivacaine and methylprednisolone with bupivacaine followed by saline.
      ,
      • Bush K.
      • Hillier S.
      A controlled study of caudal epidural injections of triamcinolone plus procaine for the management of intractable sciatica.
      Only 1 randomized placebo-controlled trial that examines the use of ESI for spinal stenosis has been published. Cuckler et al
      • Cuckler J.M.
      • Bernini P.A.
      • Wiesel S.W.
      • Booth R.E.
      • Rothman R.H.
      • Pickens G.T.
      The use of epidural steroids in the treatment of lumbar radicular pain.
      examined 37 patients with spinal stenosis who received 1 or 2 ESIs. Average subjective improvement (43%) was the same for the steroid group and for the control group at 13 to 30 months after injection. Although Cuckler
      • Cuckler J.M.
      • Bernini P.A.
      • Wiesel S.W.
      • Booth R.E.
      • Rothman R.H.
      • Pickens G.T.
      The use of epidural steroids in the treatment of lumbar radicular pain.
      concluded that the study failed to show the efficacy of ESI for LSS, the significance of the findings is diminished by reported flaws in the methodology.
      • Weinstein S.M.
      • Herring S.A.
      • Derby R.
      Contemporary concepts in spine care epidural steroid injections.
      Results of uncontrolled studies of ESI for stenosis are difficult to summarize because outcome measures and follow-up periods vary considerably. Rivest et al
      • Rivest C.
      • Katz J.N.
      • Ferrante F.M.
      • Jamison R.N.
      Effects of epidural steroid injection of pain due to lumbar spinal stenosis or herniated disks a prospective study.
      looked at patients’ reports of improvement 2 weeks after translaminar ESI for spinal stenosis and herniated nucleus pulposus. Of those with stenosis, 38% reported improvement at 2 weeks. Hoogmartens and Morelle
      • Hoogmartens M.
      • Morelle P.
      Epidural injection in the treatment of spinal stenosis.
      reported that 48% improved with ESI for LSS, but they noted that this was not significantly different from placebo. Ciocon et al
      • Ciocon J.O.
      • Galindo-Ciocon D.
      • Amaranath L.
      • Galindo D.
      Caudal epidural blocks for elderly patients with lumbar canal stenosis.
      reported considerable overall pain reduction in 30 LSS patients undergoing 3 consecutive caudal ESIs. Most of their patients reported sustained relief for at least 6 months and had persistent, significant reduction in pain scores 10 months after injection, although Ciocon stated that the patients may have had unusually mild disease. Rosen et al
      • Rosen C.D.
      • Kahanovitz N.
      • Bernstein R.
      • Viola K.
      A retrospective analysis of the efficacy of epidural steroid injections.
      reviewed 40 patients retrospectively to evaluate the effect of ESI on spinal stenosis and herniated disk, with 50% of patients with radicular symptoms receiving temporary relief with translaminar steroid injection, but long-term relief occurred in less than 25% of their patients. Similar results were obtained by Simotas et al,
      • Simotas A.C.
      • Dorey F.J.
      • Hansraj K.K.
      • Cammisa F.
      • Katz J.N.
      Nonoperative treatment for lumbar spine stenosis clinical and outcome results and a 3-year survivorship analysis.
      ,
      • Simotas A.C.
      Nonoperative treatment for lumbar spinal stenosis.
      who reported 25% with sustained improvement from conservative treatment including aggressive epidural steroid management.
      Overall, no compelling evidence exists to validate the use of ESIs for the treatment of LSS. We have concluded that most significantly absent are studies using fluoroscopically guided ESIs, which are clearly needed to ascertain the procedure’s accuracy regarding needle placement.
      • White A.H.
      • Derby R.
      • Wynne G.
      Epidural injections for the diagnosis and treatment of low-back pain.
      ,
      • Stewart H.D.
      • Quinnell R.C.
      • Dann N.
      Epidurography in the management of sciatica.
      ,
      • el-Khoury G.
      • Ehara S.
      • Weinstein J.N.
      • Montgomery W.J.
      • Kathol M.H.
      Epidural steroid injection a procedure ideally performed with fluoroscopic control.
      ,
      • Mehta M.
      • Salmon N.
      Extradural block confirmation of the injection site by x-ray monitoring.
      ,
      • Renfrew D.L.
      • Moore T.E.
      • Kathol M.H.
      • el-Khoury G.Y.
      • Lemke J.H.
      • Walker C.W.
      Correct placement of epidural steroid injections fluoroscopic guidance and contrast administration.
      The present study retrospectively looked at patients who received ESIs with fluoroscopy to determine the amount and duration of relief statistics, satisfaction with the procedure, and the rate of subsequent surgery. Our main goals in undertaking this study were to determine if, in our patient population, ESIs had been useful in managing symptoms of LSS and if any characteristics were predictive of responsiveness, or lack of response, to epidural steroid placement. Our 2 outcome measures were pain relief and improvement in function.

      Methods

      Subjects were consecutive patients over a 3-year period who received ESIs for lumbar stenosis at an outpatient spine center. Diagnosis of stenosis was made by the authors (EGD, ARC), based on the patient history of disabling back and leg pain consistent with nerve root entrapment or neurogenic claudication. Radiographs and magnetic resonance imaging showed at least 1 level of central, lateral recess, or neuroforaminal stenosis and were read independently by the neuroradiologist and the physician performing the injection. Only persons at or over the age of 55 years were included in our study. Candidates were excluded if they had undergone lumbar spinal surgery in the past 10 years.
      All participants received at least 1 or at most 7 (mean, 2.23) fluoroscopically guided
      Exposcop 7000; Ziehm International Medical System, 4181 Lathan St, Riverside, CA 92501.
      9000 C Arm; GE OEC Medical System Inc, 384 Wright Brothers Dr, Salt Lake City, UT 84116.
      transforaminal or caudal injections given by 1 of 2 physicians. Patients received 60 to 100mg of triamcinolone in combination with local anesthetic or normal saline. The injection was administered at the level of most significant lumbar nerve root or thecal sac compression or caudally to some with multilevel central canal stenosis.
      If patients had some lasting relief from the epidural but symptoms returned over the 3-year period, they received occasional reinjection. If patients had no relief from the first injection, another level or technique may have been tried. Patients not receiving significant relief from injections were evaluated for surgical decompression.
      Prospective subjects were sent a mailing that described the study, asked for verbal consent, and invited their participation. The assessment instrument, consisting of 5 standardized questions, was also included in the mailing. Approximately 1 week after the mailing was sent, contact was made by telephone by 1 of 2 investigators. The person making the call did not meet or get involved with the care of the person she called.
      After giving verbal consent, participants were first asked whether they had had surgery since the epidural(s). If they had not had surgery, they were asked the 5 questions related to the outcome of the epidurals (table 1). If they had undergone surgery since the epidurals, they were still asked about the duration of relief from the epidural (question 1) and if they would repeat the epidural (question 5). Surgical subjects were then asked 3 other questions related to the outcome of their surgery.
      Table 1Outcome Assessment Instruments
      Questionnaire for Nonsurgery Participants
      • 1.
        From the epidurals, did you have:
        No relief, relief >2 months, relief <2 months
      • 2.
        How would you rate the overall pain relief that you have had from the epidurals?
        • A
          Initially: Full, partial, none
        • B
          Currently: Full, partial, none
      • 3.
        Do you think the epidurals have improved your ability to perform your daily activities?
        Yes, partially, no
      • 4.
        What was your overall satisfaction with the epidurals?
        Very satisfied, somewhat satisfied, very unsatisfied
      • 5.
        Would you repeat the epidurals if necessary?
        Yes, no
      Questionnaire for Back Surgery Participants
      • 1.
        Questions 1 and 5 as above
      • 2.
        How would you rate your pain relief from surgery?
        Full, partial, none
      • 3.
        Has surgery improved your ability to perform your daily activities?
        Yes, partially, no
      • 4.
        What was your overall satisfaction with surgery?
        Very satisfied, somewhat satisfied, very unsatisfied
      Ethics approval for the study was obtained by the internal review board of Christiana Care Health System in Wilmington, DE.

      Data analysis

      For questions 1 and 2A, we performed a univariate analysis to consider how question-response related to each characteristic individually and a multivariate analysis to consider the effect of the characteristics in combination. A value of P less than .05 was considered statistically significant.
      For both univariate and multivariate analyses, ordinal regression, polytamous regression (when the proportional-odds assumption was invalid), or the Mantel-Haenszel test (when cell frequencies were zero) was performed.
      • Agresti A.
      ,
      • Agresti A.
      Data were analyzed using SAS, version 8.2.
      SAS Institute Inc, 100 SAS Campus Dr, Cary, NC 27513.

      Results

      Two hundred forty patients met the criteria for participation. Of those, 12 declined to participate, 11 were deceased, and 68 could not be reached. This left 149 candidates. An additional 9 persons were excluded because they had undergone spine surgery in the last 4 months, making the total number of subjects 140.

      Baseline characteristics

      Fifty-two men and 88 women participated, with a mean age ± standard deviation of 70.9±8.7 years. Mean length of time at follow-up since the first injection was 17.23±7.24 months. The mean number of injections was 2.24±1.29. Eighty participants (57%) had multilevel stenosis. Mean symptom duration was 26.2±41.6 months.
      One hundred three patients (74%) received a transforaminal and 91 (65%) a caudal epidural. Fifty-nine percent of patients received both. Twenty-five (18%) had diabetes, and 40 (29%) had a degenerative spondylolisthesis. Eleven (8%) were current smokers.

      Outcomes related to epidurals

      The subjects’ responses regarding duration of relief (fig 1A), amount of relief (fig 1B), current functional status (fig 1C), and satisfaction with the epidural(s) (fig 1D) are presented in figure 1. The surgical rate in 140 subjects was 20% (28 patients).
      Figure thumbnail GR1
      Fig 1Outcomes after ESI: (A) duration of relief, (B) amount of pain relief, (C) current functional status, and (D) satisfaction.
      Seventy-four percent of nonsurgical patients stated that they would repeat the epidural if necessary, whereas 68% of surgical patients stated they would repeat the epidural if necessary.

      Outcomes related to surgery

      Responses regarding pain relief from surgery (fig 2A), current functional status after surgery (fig 2B), and satisfaction with surgery (fig 2C) are presented in figure 2.
      Figure thumbnail GR2
      Fig 2Outcomes after surgical intervention: (A) pain relief, (B) current functional status, and (C) satisfaction. Abbreviations: Sat, satisfied; Unsat, unsatisfied.

      Correlates of clinical outcome

      Question 1

      For question 1 (duration of relief), age, gender, multilevel disease, diabetes, and smoking were not statistically significant predictors of how patients would respond to epidurals (table 2). Surgery was significant (P<.001); that is, patients who went on to have subsequent surgery were less likely to have had relief with the epidurals. Number of injections was also significant (P=.006); patients who received 2 or more injections had better results than those who received only 1 injection. Multivariate results for question 1 (table 3) indicated that number of injections remained statistically significant (P=.006). Spondylolisthesis was marginally significant (P=.078). Also, although not estimable in multivariate polytamous regression, the asymptomatic P value for the Cochrane-Mantel-Haenszel test for surgery (controlling for number of injections and spondylolisthesis) was significant (P<.001).
      Table 2Univariate Analysis for Question 1 (>2m/<2m/None) (N=140)
      VariableP ValueOdds Ratio
      Surgery
      Mantel-Haenszel test;
      <.001-
      Gender
      ordinal logistic regression;
      .221.48 (men vs women)
      Multilevel
      ordinal logistic regression;
      .941.03 (none vs some)
      Diabetes
      ordinal logistic regression;
      .461.36 (none vs some)
      Smoking
      ordinal logistic regression;
      .122.54 (some vs none)
      No. of injections
      multinomial (polytomous) regression.
      (1, 2, >2)
      .006
      Age
      ordinal logistic regression;
      .981.01 (>72y vs ≤72y)
      Spondylolesthesis
      multinomial (polytomous) regression.
      .097
      Mantel-Haenszel test;
      ordinal logistic regression;
      multinomial (polytomous) regression.
      Table 3Multivariate Analysis
      Multinomial (polytomous) regression.
      for Question 1 (>2m/<2m/None) (N=140)
      VariableP Value
      No. of injections.006
      Age.72
      Gender.29
      Multilevel.89
      Diabetes.15
      Smoking.68
      Spondylolesthesis.078
      Multinomial (polytomous) regression.

      Question 2

      For question 2A (amount of relief initially after the injection), number of injections continued to be significant (P=.007) as did gender (P=.049), with men more likely to do better than women (table 4). Diabetes was marginally statistically significant (P=.064). In multivariate analysis (table 5), number of injections remained statistically significant (P=.002), and gender was marginally so (P=.071). Diabetes was not statistically significant (P=.12).
      Table 4Univariate Analysis for Question 2A (1=Full/2=Partial/3=None): Nonsurgery Patients Only (n=112)
      VariableP ValueOdds Ratio
      Gender
      Ordinal logistic regression;
      .0492.10 (men vs women)
      Multilevel
      Ordinal logistic regression;
      .691.16 (some vs none)
      Diabetes
      multinomial (polytomous) regression.
      .064
      Smoking
      Ordinal logistic regression;
      .821.15 (some vs none)
      No. of injections
      multinomial (polytomous) regression.
      .007
      Age
      Ordinal logistic regression;
      .891.05 (≤72y vs >72y)
      Spondylolesthesis
      Ordinal logistic regression;
      .811.10 (some vs none)
      Ordinal logistic regression;
      multinomial (polytomous) regression.
      Table 5Multivariate Analysis
      Multinomial (polytomous) regression.
      for Question 2A (1=Full/2=Partial/3=None): Nonsurgery Patients Only (n=112)
      VariableP Value
      No. of injections.002
      Age.81
      Gender.071
      Multilevel.78
      Diabetes.12
      Smoking.81
      Spondylolesthesis.91
      Multinomial (polytomous) regression.

      Discussion

      The present study sought to explore the use of fluoroscopically guided ESIs for treatment of stenosis. Amundsen et al,
      • Amundsen T.
      • Weber H.
      • Nordal H.
      • Magnaes B.
      • Abdelnoor M.
      • Lilleas F.
      Lumbar spinal stenosis: conservative or surgical management? A prospective 10-year study.
      Atlas et al,
      • Atlas S.J.
      • Keller R.B.
      • Robson D.
      • Deyo R.A.
      • Singer D.E.
      Surgical and nonsurgical management of lumbar spinal stenosis four-year outcomes from the Maine lumbar spine study.
      and others
      • Johnsson K.E.
      • Uden A.
      • Rosen I.
      The natural course of lumbar spinal stenosis.
      ,
      • Herno A.
      • Airaksinen O.
      • Saari T.
      • Luukkonen M.
      Lumbar spinal stenosis a matched-pair study of operated and non-operated patients.
      have shown that the majority of patients with stenosis managed conservatively do not worsen over time. Amundsen followed up with stenotic patients for 10 years and found no clinically significant deterioration in symptoms in the majority of patients. In addition, delayed surgery resulted in just as favorable outcomes as immediate surgery. Atlas
      • Atlas S.J.
      • Keller R.B.
      • Robson D.
      • Deyo R.A.
      • Singer D.E.
      Surgical and nonsurgical management of lumbar spinal stenosis four-year outcomes from the Maine lumbar spine study.
      found that conservatively managed patients remained the same or showed a trend toward improvement with time. Thus, it appears that stenosis is a degenerative condition that does not necessarily symptomatically worsen with time but has periodic exacerbations and remittances.
      Our data suggest that some of the patients in our population found epidurals to be helpful in managing their symptoms during these exacerbations. Thirty-two percent had more than 2 months of pain relief. In addition, at the time of contact, 45% of our patients were reporting some amount of relief and 53% sustained improvement in function at a mean of 18 months after their first injection. Varying follow-up times make comparison difficult, but 2 other studies that looked at long-term relief reported 25% with sustained improvement.
      • Rosen C.D.
      • Kahanovitz N.
      • Bernstein R.
      • Viola K.
      A retrospective analysis of the efficacy of epidural steroid injections.
      ,
      • Simotas A.C.
      • Dorey F.J.
      • Hansraj K.K.
      • Cammisa F.
      • Katz J.N.
      Nonoperative treatment for lumbar spine stenosis clinical and outcome results and a 3-year survivorship analysis.
      An interesting comparison can be made to the study of Rivest et al,
      • Rivest C.
      • Katz J.N.
      • Ferrante F.M.
      • Jamison R.N.
      Effects of epidural steroid injection of pain due to lumbar spinal stenosis or herniated disks a prospective study.
      who reported 38% short-term improvement from epidurals. In the short term (<2mo in our study), 71% of our patients were reporting improvement. This discrepancy may highlight the importance of approach and documenting appropriate placement of medication by fluoroscopy. Most studies, (including Rivest’s), describe a translaminar approach. We used a transforaminal or caudal approach, both of which may allow more effective placement of medication. In contrast to the present study, most previous studies on epidurals and stenosis (with 1 exception
      • Simotas A.C.
      • Dorey F.J.
      • Hansraj K.K.
      • Cammisa F.
      • Katz J.N.
      Nonoperative treatment for lumbar spine stenosis clinical and outcome results and a 3-year survivorship analysis.
      ) did not use fluoroscopy. Without fluoroscopy, the benefit of epidurals may be underreported, because poor results may occur as a result of the steroid not reaching the epidural space and the desired nerve roots. Many studies suggest that, without fluoroscopic guidance, 40% of caudal and 30% of translaminar injections are not properly placed in the epidural space
      • el-Khoury G.
      • Ehara S.
      • Weinstein J.N.
      • Montgomery W.J.
      • Kathol M.H.
      Epidural steroid injection a procedure ideally performed with fluoroscopic control.
      ,
      • Mehta M.
      • Salmon N.
      Extradural block confirmation of the injection site by x-ray monitoring.
      ,
      • Renfrew D.L.
      • Moore T.E.
      • Kathol M.H.
      • el-Khoury G.Y.
      • Lemke J.H.
      • Walker C.W.
      Correct placement of epidural steroid injections fluoroscopic guidance and contrast administration.
      ; thus their therapeutic benefit derives only through systemic absorption.
      Forty-six percent of our population was very satisfied with their treatment, and 74% were at least somewhat satisfied. As in the study by Simotas et al,
      • Simotas A.C.
      • Dorey F.J.
      • Hansraj K.K.
      • Cammisa F.
      • Katz J.N.
      Nonoperative treatment for lumbar spine stenosis clinical and outcome results and a 3-year survivorship analysis.
      our satisfaction rates are somewhat higher than the percentages would suggest for duration of relief. This finding may represent patient satisfaction with the process of care as well as the results from the epidural.
      There were no specific baseline characteristics that forecast the outcome from epidurals in our study. Age, diabetes, smoking, and multilevel disease did not predict response to the epidural. Patients with spondylolisthesis showed a trend toward less favorable results, although it was not statistically significant. In our population, men were more likely to have more than 2 months of relief, but that factor did not remain statistically significant in the multivariate analysis. Because our sample size was comparatively small (N=140), our present study could not detect relatively small differences, although others
      • Rivest C.
      • Katz J.N.
      • Ferrante F.M.
      • Jamison R.N.
      Effects of epidural steroid injection of pain due to lumbar spinal stenosis or herniated disks a prospective study.
      ,
      • Rosen C.D.
      • Kahanovitz N.
      • Bernstein R.
      • Viola K.
      A retrospective analysis of the efficacy of epidural steroid injections.
      ,
      • Simotas A.C.
      • Dorey F.J.
      • Hansraj K.K.
      • Cammisa F.
      • Katz J.N.
      Nonoperative treatment for lumbar spine stenosis clinical and outcome results and a 3-year survivorship analysis.
      ,
      • Herno A.
      • Airaksinen O.
      • Saari T.
      • Luukkonen M.
      Lumbar spinal stenosis a matched-pair study of operated and non-operated patients.
      have also reported no specific characteristics predicting outcome from the epidural. One study
      • Simotas A.C.
      • Dorey F.J.
      • Hansraj K.K.
      • Cammisa F.
      • Katz J.N.
      Nonoperative treatment for lumbar spine stenosis clinical and outcome results and a 3-year survivorship analysis.
      found that age correlated with outcome, but when scoliotic patients were removed, it was only weakly correlated.
      The surgical rate of our population was 20%, similar to the surgical rate of 18% in the Simotas study
      • Simotas A.C.
      • Dorey F.J.
      • Hansraj K.K.
      • Cammisa F.
      • Katz J.N.
      Nonoperative treatment for lumbar spine stenosis clinical and outcome results and a 3-year survivorship analysis.
      and the 27% surgical rate reported by Cuckler et al.
      • Cuckler J.M.
      • Bernini P.A.
      • Wiesel S.W.
      • Booth R.E.
      • Rothman R.H.
      • Pickens G.T.
      The use of epidural steroids in the treatment of lumbar radicular pain.
      Because we were primarily looking at outcomes from epidurals, it was beyond the scope of the present study to report extensive and long-term surgical outcomes; nonetheless, we did collect pain relief and functional status data for our surgical patients at least 4 months after surgery. Maximum benefit from surgery is attained by 3 months after surgery.
      • Atlas S.J.
      • Keller R.B.
      • Robson D.
      • Deyo R.A.
      • Singer D.E.
      Surgical and nonsurgical management of lumbar spinal stenosis four-year outcomes from the Maine lumbar spine study.
      Four months to 2 years after surgery, 89% of our population reported full or partial relief, as compared with 77% reported by Atlas et al
      • Atlas S.J.
      • Keller R.B.
      • Robson D.
      • Deyo R.A.
      • Singer D.E.
      Surgical and nonsurgical management of lumbar spinal stenosis four-year outcomes from the Maine lumbar spine study.
      at 3 months and 1 year after surgery. Functional status was also similarly improved in our population, with 75% reporting functional gains after surgery, in line with the 81% of participants in the Atlas
      • Atlas S.J.
      • Keller R.B.
      • Robson D.
      • Deyo R.A.
      • Singer D.E.
      Surgical and nonsurgical management of lumbar spinal stenosis four-year outcomes from the Maine lumbar spine study.
      study who reported improved quality of life.
      Several methods limitations moderate our findings. The present study has all the inherent limitations of a retrospective study. Patients’ recall may be inaccurate and biased. There was no control population, so some of the reported benefits may be as a result of placebo effect. Further, we did not use a validated outcome tool or attempt to track other conservative interventions that may have affected outcome.
      We did not have baseline measurements of severity of stenosis, but radiographic evidence of stenosis severity imperfectly correlates with severity of symptoms and nonoperative outcome.
      • Simotas A.C.
      • Dorey F.J.
      • Hansraj K.K.
      • Cammisa F.
      • Katz J.N.
      Nonoperative treatment for lumbar spine stenosis clinical and outcome results and a 3-year survivorship analysis.
      No validated system for rating stenosis radiographically exists, and physicians are only moderately reliable in agreeing on whether patients have stenosis and are unreliable in grading the degree.
      • Drew B.
      • Bhandari M.
      • Kulkarni A.V.
      • Louw D.
      • Reddy K.
      • Dunlop B.
      Reliability in grading the severity of lumbar spinal stenosis.
      In our literature review, no features of radiographic severity correlated with nonsurgical outcome, although 1 study
      • Simotas A.C.
      • Dorey F.J.
      • Hansraj K.K.
      • Cammisa F.
      • Katz J.N.
      Nonoperative treatment for lumbar spine stenosis clinical and outcome results and a 3-year survivorship analysis.
      found that patients with scoliosis tended to have poorer outcomes with epidurals.

      Conclusions

      ESIs provided approximately one third of our patient population with more than 2 months of relief, and more than one half with improvement in function. The majority of patients were satisfied with ESIs as a form of treatment in assisting them through the more painful periods of their condition, although many required reinjection for periodic flare-ups over the 3-year period. Future research should be directed at a prospective, controlled study of epidurals, as well as at their role as part of a structured conservative management program.
      Suppliers
      aExposcop 7000; Ziehm International Medical System, 4181 Lathan St, Riverside, CA 92501.
      b9000 C Arm; GE OEC Medical System Inc, 384 Wright Brothers Dr, Salt Lake City, UT 84116.
      cSAS Institute Inc, 100 SAS Campus Dr, Cary, NC 27513.

      Acknowledgements

      We thank Edward Pequignot, MS, for the statistical analysis.

      References

        • Atlas S.J.
        • Deyo R.A.
        • Keller R.B.
        • et al.
        The Maine Lumbar Spine Study, Part III.
        Spine. 1996; 21 (discussion 1794-5): 1787-1794
        • Atlas S.J.
        • Keller R.B.
        • Robson D.
        • Deyo R.A.
        • Singer D.E.
        Surgical and nonsurgical management of lumbar spinal stenosis.
        Spine. 2000; 25: 556-562
        • Robechi A.
        • Capra R.
        L’idrocortisone (composto F).
        Minerva Med. 1952; 98: 1259-1263
        • Rydevik B.
        • Brown M.D.
        • Lundborg G.
        Pathoanatomy and pathophysiology of nerve root compression.
        Spine. 1984; 9: 7-15
        • Olmarker K.
        • Redevik B.
        • Holm S.
        Edema formation in spinal nerve roots induced by experimental, graded compression.
        Spine. 1989; 14: 569-573
        • Kantrowitz F.
        • Robinson D.R.
        • McGuire M.B.
        • Levine L.
        Corticosteroids inhibit prostaglandin production by rheumatoid synovia.
        Nature. 1975; 258: 737-739
        • Fukusaki M.
        • Kobayashi I.
        • Hara T.
        • Sumikawa K.
        Symptoms of spinal stenosis do not improve after epidural steroid injection.
        Clin J Pain. 1998; 14: 148-151
        • Johansson A.
        • Hao J.
        • Sjolund B.
        Local corticosteroid application blocks transmission in normal nociceptor C-fibres.
        Acta Anaesthesiol Scand. 1990; 34: 335-338
        • Breivik H.
        • Hesla P.E.
        • Molnar I.
        • Lind B.
        Treatment of chronic low back pain and sciatica.
        in: Bonica J.J. Albe-Fessard D. Advances in pain research and therapy. 1. Raven Pr, New York1976: 927-932
        • Beliveau P.
        A comparison between epidural anesthesia with and without corticosteroids in the treatment of sciatica.
        Rheumatol Phys Med. 1971; 11: 40-43
        • Bush K.
        • Hillier S.
        A controlled study of caudal epidural injections of triamcinolone plus procaine for the management of intractable sciatica.
        Spine. 1991; 16: 572-575
        • Daly P.
        Caudal epidural anesthesia in lumbosciatic pain.
        Anaesthesia. 1970; 25: 346-348
        • Mathews J.A.
        • Mills S.B.
        • Jenkins V.M.
        • et al.
        Back pain and sciatica.
        Br J Rheumatol. 1987; 26: 416-423
        • Yates D.W.
        A comparison of the types of epidural injection commonly used in the treatment of intervertebral disc herniation.
        Rheumatol Rehabil. 1978; 17: 181-186
        • Cuckler J.M.
        • Bernini P.A.
        • Wiesel S.W.
        • Booth R.E.
        • Rothman R.H.
        • Pickens G.T.
        The use of epidural steroids in the treatment of lumbar radicular pain.
        J Bone Joint Surg Am. 1985; 67: 63-66
        • Weinstein S.M.
        • Herring S.A.
        • Derby R.
        Contemporary concepts in spine care.
        Spine. 1995; 20: 845-848
        • Rivest C.
        • Katz J.N.
        • Ferrante F.M.
        • Jamison R.N.
        Effects of epidural steroid injection of pain due to lumbar spinal stenosis or herniated disks.
        Arthritis Care Res. 1998; 11: 291-297
        • Hoogmartens M.
        • Morelle P.
        Epidural injection in the treatment of spinal stenosis.
        Acta Orthop Belg. 1987; 53: 409-411
        • Ciocon J.O.
        • Galindo-Ciocon D.
        • Amaranath L.
        • Galindo D.
        Caudal epidural blocks for elderly patients with lumbar canal stenosis.
        J Am Geriatr Soc. 1994; 42: 593-596
        • Rosen C.D.
        • Kahanovitz N.
        • Bernstein R.
        • Viola K.
        A retrospective analysis of the efficacy of epidural steroid injections.
        Clin Orthop. 1988; Mar: 270-272
        • Simotas A.C.
        • Dorey F.J.
        • Hansraj K.K.
        • Cammisa F.
        • Katz J.N.
        Nonoperative treatment for lumbar spine stenosis.
        Spine. 2000; 25: 197-208
        • Simotas A.C.
        Nonoperative treatment for lumbar spinal stenosis.
        Clin Orthop. 2001; Mar: 153-161
        • White A.H.
        • Derby R.
        • Wynne G.
        Epidural injections for the diagnosis and treatment of low-back pain.
        Spine. 1980; 5: 78-86
        • Stewart H.D.
        • Quinnell R.C.
        • Dann N.
        Epidurography in the management of sciatica.
        Br J Rheumatol. 1987; 26: 424-429
        • el-Khoury G.
        • Ehara S.
        • Weinstein J.N.
        • Montgomery W.J.
        • Kathol M.H.
        Epidural steroid injection.
        Radiology. 1988; 168: 554-557
        • Mehta M.
        • Salmon N.
        Extradural block.
        Anaesthesia. 1985; 40: 1009-1012
        • Renfrew D.L.
        • Moore T.E.
        • Kathol M.H.
        • el-Khoury G.Y.
        • Lemke J.H.
        • Walker C.W.
        Correct placement of epidural steroid injections.
        Am J Neuroradiol. 1991; 12: 1003-1007
        • Agresti A.
        Analysis of ordinal categorical data. John Wiley & Sons, New York1984
        • Agresti A.
        Categorical data analysis. John Wiley & Sons, New York1990
        • Amundsen T.
        • Weber H.
        • Nordal H.
        • Magnaes B.
        • Abdelnoor M.
        • Lilleas F.
        Lumbar spinal stenosis: conservative or surgical management? A prospective 10-year study.
        Spine. 2000; 25 (discussion 1435-6): 1424-1435
        • Johnsson K.E.
        • Uden A.
        • Rosen I.
        The natural course of lumbar spinal stenosis.
        Clin Orthop. 1992; Jun: 82-86
        • Herno A.
        • Airaksinen O.
        • Saari T.
        • Luukkonen M.
        Lumbar spinal stenosis.
        Br J Neurol. 1996; 10: 461-465
        • Drew B.
        • Bhandari M.
        • Kulkarni A.V.
        • Louw D.
        • Reddy K.
        • Dunlop B.
        Reliability in grading the severity of lumbar spinal stenosis.
        J Spinal Dis. 2000; 13: 253-255