Epidural corticosteroid injection
(ESI) is a method of relieving pain associated with leg, back, neck and arm
caused by inflamed spinal nerves, especially in those people suffering from
spinal stenosis, spondylolysis, herniated disc, degenerative disc and sciatica.
Sciatica is a common type of low
back pain that radiates down through the hips and buttocks and down the legs -
typically only on one side of the body. The pain varies from a mild ache to a
sharp burning sensation. Some people experience tingling or numbness or muscle
weakness in the affected leg. Sciatica generally occurs when a herniated disc
or a bone spur on the spine compresses part of the nerve causing inflammation
and pain. Although the pain mostly resolves in a few weeks with conservative
care for sciatica, invasive procedures such as ESI is resorted to when the
conservative care options fail to offer relief even after six weeks of
Since existing reviews and
guidelines on the efficacy of ESI treatment for sciatica are conflicting,
Rafael Zambelli Pinto, of the Sydney Medical School at the University of
Sydney, and his colleagues reviewed and conducted meta-analysis of 23 clinical
trials to determine the efficacy of epidural corticosteroid injections for
sciatica compared with placebo.
They chose the parameters of leg
pain, back pain, and disability, which they rated on a scale of zero (no pain
or disability) to 100 (worst possible pain or disability). Pain being a
subjective sensation, it is difficult to evaluate objectively in clinical
trials. Thresholds for clinically important change in the range of 10 to 30
were thus considered for these outcomes. Short term effects ranging from more
than 2 weeks but less than 3 months or less and long term effects of 12 months
or more were calculated.
The results of the meta-analysis
showed a small, but statistically significant, effect of epidural
corticosteroid injections for short-term leg pain and for short-term disability
as compared with placebo. But the follow up a year later showed that the
long-term effects of corticosteroid injections were not significantly different
from placebo. Similarly, ESIs showed no significant benefits in relieving back
pain associated with sciatica.
'Despite the statistically
significant short-term effects on pain and disability favoring the intervention
over the placebo, the small size of the treatment effect challenges the
clinical utility of this procedure', noted the authors.
'Until the current evidence
changes we would recommend patients with acute sciatica receive a course of
conservative care before any invasive treatment approach is considered. This
conservative care should preferably follow evidence-based guidelines, such as
those for neuropathic pain', they suggested.
'For those patients who have
persistent and disabling sciatica symptoms, epidural corticosteroids and
surgery are the available treatment options, with short-term effects that need
to be considered in the shared decision-making process.'
Pinto RZ, Maher CG, Ferreria ML, Hancock M, Oliveira
VC, McLachlan AJ, Koes B, Ferreira PH.
Epidural corticosteroid injections in the management of sciatica: a
systematic review and meta-analysis. Annals of Internal Medicine 2012; doi: