Background: Steroids often are administered into the epidural space through the transforaminal epidural (TFE) route to treat lumbosacral radicular pain secondary to herniated intervertebral discs. However, their efficacy and safety compared with transforaminal epidural local anesthetics (LAs) or saline injections is unclear.
Methods: We reviewed randomized controlled trials that compared TFE injections of steroids (with or without LA) with LA or saline in adult outpatients with lumbosacral radicular pain secondary to herniated intervertebral disks. Databases searched included MEDLINE, EMBASE, Cochrane central register of controlled trials, Cochrane database of systematic reviews, and Google Scholar up to February 2015. Data on scores of numerical rating scale for pain, validated scores for measuring physical disability and quality of life, and incidence of surgery measured at 1 month to 2 years after the interventions were meta-analyzed. Strength of evidence was classified with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system.
Results: Eight randomized controlled trials including 771 patients (366 in steroid and 405 in comparator groups) were included. There was variability in the studies in the dose of TFE steroids, frequency, and number of procedures. Patients who received TFE steroids reported a significant, but clinically modest, reduction in mean pain scores (0-10 scale) compared with LA/saline (-0.97 points; 95% confidence interval, -1.42 to -0.51 points; P < 0.0001, I² = 90%; GRADE weak recommendation; moderate-quality evidence) at 3 months after the interventions. TFE steroids did not decrease physical disability at 1 to 3 months after the intervention (GRADE strong recommendation ↓; high-quality evidence) or incidence of surgery at 12 months after the intervention (GRADE strong recommendation ↓; moderate-quality evidence) compared with LA/saline.
Conclusions: TFE steroids provide modest analgesic benefit at 3 months in patients with lumbosacral radicular pain secondary to herniated intervertebral disks, but they have no impact on physical disability or incidence of surgery. There was a high degree of heterogeneity among the publications included in this meta-analysis. Well-designed, large, randomized studies are required to evaluate appropriate dosages, adverse effects, number of procedures, and the effect of this intervention on psychological disability and quality of life.