Evaluation of the Effectiveness of Lumbar Interlaminar Epidural Injections in Managing Chronic Pain of Lumbar Disc Herniation or Radiculitis: A Randomized, Double-Blind, Controlled Trial

Abstract

Background: The pathophysiology of lumbar radicular pain is the subject of ongoing research, with a reported prevalence of sciatica or radiculitis ranging from 1.2% to 43%. Among the numerous nonsurgical interventions available, epidural injections are the most commonly performed interventions in the United States in managing chronic low back and lower extremity pain. Study Design: A randomized, double-blind, controlled trial. Setting: An interventional pain management practice, a specialty referral center, a private practice setting in the United States. Objective: To evaluate the effectiveness of lumbar interlaminar epidural injections with local anesthetic, with or without steroids, in managing chronic low back and lower extremity pain secondary to disc herniation or radiculitis in providing effective and long-lasting pain relief. Methods: Patients were assigned to one of 2 groups with local anesthetic only or with local anesthetic mixed with non-particulate betamethasone. Randomization was performed by computer-generated random allocations sequence by simple randomization. Seventy patients were included in this analysis. Outcomes Assessment: Patient outcomes were measured at baseline, 3, 6, and 12 months post-treatment with the Numeric Rating Scale (NRS), the Oswestry Disability Index 2.0 (ODI), employment status, and opioid intake. Decrease of ≥ 50% of NRS scores and Oswestry scores were considered significant. Results: Significant pain relief (≥ 50%) was seen at 12 months in 74% of patients in Group I and 86% in Group II, and 69% and 83% in ODI scores respectively. Significant differences were noted in pain relief characteristics at 6 months between Group I and Group II (P = 0.001) and functional status improvement was significantly better in Group II at 6 months and 12 months (P = 0.019 and 0.045). The overall average procedures per year were 4.3 in Group I and 4.2 in Group II with an average total relief per year of 42.2 ± 10.5 weeks in Group I and 41.4 ± 11.0 weeks in Group II over a period of 52 weeks in the successful group. Limitations: The study limitations include the lack of a placebo group and the fact that this is a preliminary report of 35 patients in each group. Conclusion: Overall, 74% of patients in Group I without steroids and 86% in Group II with steroids with lumbar disc herniation or radiculitis might benefit from lumbar interlaminar epidural injections. Key words: Chronic low back pain, lower extremity pain, disc herniation, radiculitis, lumbar interlaminar epidural injections, epidural steroids, local anesthetic