Preliminary results of a randomized, equivalence trial of fluoroscopic caudal epidural injections in managing chronic low back pain: Part 2--Disc herniation and radiculitis.

BACKGROUND The pathophysiology of lumbar radicular pain is a subject of ongoing research. The prevalence of sciatica or radiculitis ranges from 1.2% to 43%. Epidural injections are one of the most commonly performed interventions in the United States in managing chronic low back and lower extremity pain secondary to disc herniation and radiculitis. There is a paucity of evidence with contemporary methodology used in performing epidural injections under fluoroscopy and based on pain relief and functional status improvement. STUDY DESIGN A randomized, double-blind, equivalence 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 caudal epidural injections 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 and evaluate the differences between local anesthetic with or without steroids. METHODS Patients were assigned to one of 2 groups; Group I patients received caudal epidural injections with an injection of local anesthetic (lidocaine 0.5%), whereas, Group II patients received caudal epidural injections with 0.5% lidocaine 9 mL mixed with 1 mL of steroid. Randomization was performed by computer-generated random allocations sequence by simple randomization. OUTCOMES ASSESSMENT Multiple outcome measures were utilized which included the Numeric Rating Scale (NRS), the Oswestry Disability Index 2.0 (ODI), employment status, and opioid intake with assessment at 3 months, 6 months, and 12 months post-treatment. Significant pain relief was defined as 50% or more, whereas significant improvement in disability score was defined as a reduction of 40% or more. RESULTS The percentage of patients with significant pain relief of 50% or greater at 12 months was 79% in Group I and 81% in Group II. Reduction of Oswestry scores of at least 40% was seen in 83% of the patients in Group I and 91% in Group II. The overall average procedures per year were 3.9 +/- 1.26 in Group I and 3.6 +/- 1.08 in Group II with an average total relief per year of 35.2 +/- 17.18 weeks in Group I and 35.9 +/- 15.34 weeks in Group II over a period of 52 weeks. LIMITATIONS The results of this study are limited by lack of a placebo group and a preliminary report of 42 patients in each group. CONCLUSION Caudal epidural injections with or without steroids may be effective in patients with disc herniation or radiculitis with between 79% to 91% of patients showing significant pain relief and improvement in functional status.