A New Systematic Review Summarizes the Efficacy of Epidural Spinal Injections for Chronic Back Pain

Results from a new systematic review show that epidural steroid injections (ESIs) have modest efficacy for reducing short-term pain and disability caused by radiculopathy and possible efficacy in reducing short-term disability caused by spinal stenosis. The study findings, which were published in Neurology, the journal of the American Academy of Neurology (AAN), suggest also that ESIs may have possible efficacy in reducing long-term disability from radiculopathy and lumbar spinal stenosis in some patients. The new findings confirm the field’s prior understanding of the limited and short-term efficacy of ESIs for treating lumbosacral radicular pain.

The systematic review was conducted to summarize the evidence of ESIs for chronic back pain for neurologists and other clinicians. Researchers analyzed 90 randomized controlled trials (RCTs) published between 2005 and 2021 which evaluated the efficacy of ESIs. A panel of clinicians evaluated the evidence for ESI therapy for different pathologies, outcomes, and spinal levels.

Radiculopathy:

• Short-term pain: Individuals with radiculopathy treated with ESIs were more likely to report reduced pain up to 3 months vs those not receiving ESI therapy, with a success rate difference (SRD) of -24.0% (95% CI, -34.9 to -12.6; number needed to treat [NNT], 4).
• Short-term disability: The SRD for disability up to 3 months was -16.0% for people with radiculopathy (95% CI, -26.6 to -5; NNT, 6).
• Long-term pain: There was insufficient evidence to establish the efficacy of ESIs for reducing long-term pain in radiculopathy.
• Long-term disability: The SRD for disability up to 6 months or more was -11.1% for people with radiculopathy (95% CI, -25.3 to 3.6; NNT, 9).
• The studies included in the systematic review focused on lower back radiculopathy, limiting evidence of the efficacy of ESI therapy for cervical radiculopathy.

Lumbar spinal stenosis:

• Short-term pain: ESI therapy was not shown to reduce short-term pain in people with lumbar spinal stenosis.
• Short-term disability: Individuals with lumbar spinal stenosis were more likely to report reduced disability up to 3 months vs those not receiving ESI therapy, with an SRD of -26.2% (95% CI, -52.4 to 3.6; NNT, 7.6).
• Long-term pain: There was insufficient evidence to establish the efficacy of ESIs for reducing long-term pain in lumbar spinal stenosis.
• Long-term disability: The SRD for disability up to 6 months or more was -11.8% for people with lumbar spinal stenosis (95% CI, -26.9 to 3.8; NNT, 8).
• The systematic review provided insufficient evidence to establish the efficacy of ESI therapy for cervical spinal stenosis.

“Our review affirms the limited effectiveness of epidural steroid injections in the short term for some forms of chronic back pain,” said study author Pushpa Narayanaswami, MD, Neurologist at Beth Israel Deaconess Medical Center and Fellow of the AAN. “We found no studies looking at whether repeated treatments are effective or examining the effect of treatment on daily living and returning to work. Future studies should address these gaps.”