Epidural steroid injections for back pain may not be superior

 An injection for lower back pain (transforaminal epidural steroid injections), which is widely seen as being superior to interlaminar injections, may not actually deliver significantly superior results in terms of pain relief or functional improvement, says a review of trials presented at the American Academy of Pain Medicine 30th Annual Meeting.

“I think these findings are definitely controversial, but I have had numerous people say to me that this is in fact very consistent with their experience using these two modalities,” says lead author Dr George Chang Chien.

Epidural injections deliver steroids into the space around spinal nerve roots to reduce inflammation and pain. A transforaminal injection is associated with potentially severe side effects that are less common with interlaminar epidural steroid injections.

Dr Chang Chien and his colleagues evaluated data on eight trials (involving 506 patients) that compared transforaminal and interlaminar epidural steroid injections for the treatment of lower back pain.

People who received transforaminal epidural steroid injections showed about a 15% greater improvement for short-term pain relief after two weeks. But at one or six months there were no significant differences between the approaches.

In terms of functional improvement, the interlaminar injection groups showed slightly better results than transforaminal at two weeks (56.4% vs 49.4%). But the differences in combined data on the two approaches were only slight (44.8% for interlaminar and 40.1% for transforaminal).

“These results suggest that the difference in efficacy between these two modalities may be less significant than previously thought,” says Dr Chang Chien.

Yet the fact that transforaminal injections have greater short-term improvement could be important in terms of longer-term outcomes.

“The evidence for short-term relief — less than six weeks — with epidural steroid injections is strong, [and the] injections may also provide long-term relief by allowing patients to resume their normal activities and participate in physical therapy or therapeutic exercise programs,” says Prof Stephen Cohen from Johns Hopkins University, Baltimore, Maryland. “In this regard, the better short-term pain relief is important.”

Before deciding which approach to opt for, the potential side effects need to be closely scrutinised.