Transforaminal epidural injections in chronic lumbar disc herniation: a randomized, double-blind, active-control trial.

BACKGROUND: The estimated prevalence of lumbar radiculopathy has been described as 9.8 per 1,000 cases of low back pain. There are various surgical and nonsurgical modalities for treating lumbar disc herniation or radicular pain, including epidural injections. Epidural injection administration routes include transforaminal, interlaminar, and caudal approaches. The transforaminal approach requires the smallest volume to reach the primary site of pathology. Systematic reviews have yielded highly variable results, but a recent systematic review showed no significant difference among the 3 approaches.

STUDY DESIGN: A randomized, controlled, double blind, active control trial.

SETTING: An interventional pain management practice, a private specialty referral center in the United States.

OBJECTIVES: To assess the effectiveness of transforaminal epidural injections of local anesthetic with or without steroids in managing chronic low back and lower extremity pain in patients with disc herniation and radiculitis.

METHODS: One hundred twenty patients were randomly assigned to 2 groups: Group I received 1.5 mL of 1% preservative-free lidocaine, followed by 0.5 mL of sodium chloride solution. Group II received 1% lidocaine, followed by 3 mg, or 0.5 mL of betamethasone. The sodium chloride solution and betamethasone were either clear liquids or were provided in opaque-covered syringes.

OUTCOMES ASSESSMENT: The primary outcome measure was significant improvement (at least 50%) measured by the average Numeric Rating Scale (NRS) and the Oswestry Disability Index 2.0 (ODI). Secondary outcome measures were employment status and opioid intake.

RESULTS: At 2 years there was significant improvement in all participants in 65% who received local anesthetic alone and 57% who received local anesthetic and steroid. When separated into non-responsive and responsive categories based on initial relief of at least 3 weeks with 2 procedures, significant improvement (at least 50% improvement in pain and function) was seen in 80% in the local anesthetic group and 73% in the local anesthetic with steroid group.

LIMITATIONS: Presumed limitations of this evaluation include the lack of a placebo group.

CONCLUSION: Transforaminal epidural injections of local anesthetic with or without steroids might be an effective therapy for patients with disc herniation or radiculitis. The present evidence illustrates the lack of superiority of steroids compared with local anesthetic at 2-year follow-up.