Clinical Question

Do epidural corticosteroid injections safely reduce pain and disability for patients with sciatica?

Bottom Line

Epidural corticosteroid injections provide a small and probably clinically insignificant reduction in leg and back pain in the immediate term (less than two weeks), and a small to moderate reduction in disability in the short and intermediate terms. Adverse events and safety were not well reported. (Level of Evidence = 1a−)

Synopsis

The review from the Cochrane Collaboration is an update to a previous systematic review of epidural corticosteroid injections for low back pain associated with sciatica. Inclusion in a trial could be based on the clinical evaluation, and patients with spinal stenosis or previous surgery were excluded. The reviewers identified 25 studies with 2,470 participants that compared corticosteroid with placebo (a local anesthetic that was used to mask injection vs. no injection). The quality assessment found that failure to mask study personnel or outcome assessors—and in some cases, patients—was common. Leg pain decreased significantly in the immediate term of less than two weeks (15 points on a 100-point scale), but much less in the short term, from two weeks to three months (five points). There was no benefit in the intermediate term (three months to 12 months) or long term (longer than 12 months). A 15-point difference on a 100-point scale is probably clinically significant, but a five-point difference is not. Back pain improved only in the immediate term (11 points on a 100-point scale, which is of borderline clinical significance); there was no significant reduction in back pain during any follow-up period beyond two weeks. It is important to note that only a single study with 158 patients reported results for the immediate term period (less than two weeks). Disability was decreased in the short and medium term (two weeks to 12 months), with a small to moderate effect size, as measured by the standardized mean difference (−0.20 to −0.27). Adverse events included headache and increased back pain in some participants, but they were not well or consistently reported, and safety was not well reported.

Study design: Meta-analysis (randomized controlled trials)

Funding source: Government

Setting: Outpatient (any)

Reference: Oliveira CB, Maher CG, Ferreira ML, et al. Epidural corticosteroid injections for sciatica: an abridged Cochrane systematic review and meta-analysis. Spine (Phila Pa 1976). 2020;45(21):E1405–E1415.

Editor's Note: Dr. Ebell is deputy editor for evidence-based medicine for AFP and cofounder and editor-in-chief of Essential Evidence Plus, published by Wiley-Blackwell.