Relevance of the review

Dysfunction in the spinal nerve root may cause radiating leg pain below the knee, diagnosed as lumbosacral radicular pain (also known as sciatica). It is associated with dermatomal leg pain or at least one neurological deficit (e.g. muscle weakness, reflex changes, sensory deficits). As compared to people with axial low-back pain, these patients may frequently experience more severe pain, poorer quality of life with high rates of disability and work absence.

The most popular non-surgical therapeutic procedure for lumbosacral radicular pain worldwide is epidural corticosteroid injection that delivers a corticosteroid dose into the epidural space, with the aim of reducing local inflammatory process, consequently relieving the pain. The objective of this review is to investigate the efficacy and safety of epidural corticosteroid injection compared with placebo injection on pain and disability in patients with lumbosacral radicular pain.

This review is important for

Patients with Lumbosacral radicular pain (sciatica) and their families / care-givers, health professionals and researchers dealing with lumbosacral-radicular-pain management, general physicians, and policy makers.

Key outcomes of the review

This Cochrane systematic review is an update of a previously published review in the Annals of Internal Medicine in 2012. Twenty-five clinical trials (published till 25 September 2019) were included in the analysis, involving 2470 adults (mean age between 37.3 to 52.8 years). These studies had a follow-up ranging from 12 hours to 1 year.

At short-term follow-up, epidural corticosteroid injection is probably slightly more effective compared to placebo, in reducing leg pain and disability (moderate level of evidence); however, these treatment effects are small. Most trials provided insufficient information regarding adverse events (at immediate or at short-term follow-up); moreover, it is uncertain whether epidural corticosteroid injection has no minor adverse effects compared to placebo injection. Minor adverse events may include increased pain during or after the injection, non-specific headache, post-dural puncture headache, irregular periods, accidental dural puncture, thoracic pain, non-local rash, sinusitis, vasovagal response, hypotension, nausea, and tinnitus. One study reported a major drug reaction (retroperitoneal haematoma) in one patient with on-going anticoagulant therapy.

Authors’ conclusions

This review found that epidural corticosteroid injection probably slightly reduces leg pain and disability at short-term follow-up in people with lumbosacral radicular pain. These treatment effects are small, mainly evident at short-term follow-up and may not be considered clinically important by patients and clinicians (i.e. mean difference lower than 10%). In addition, no minor or major adverse events were reported at short-term follow-up, though the quality of evidence on this outcome is very low.

Future recommendations

Authors of the review recommended further studies to clarify the efficacy and tolerability of epidural corticosteroid injection in lumbosacral radicular pain. The clinical trials should report to methodological features such as appropriate allocation, concealment and blinding of care providers to minimise the potential for biased estimates of treatment and harmful effects.

Comment by Sunita Gudwani