09/19/2013 09:11 am ET

Steroid Shots For Back Pain May Work Because Of The Shots, Not The Steroids: Review

syringe in a hand close up shot
syringe in a hand close up shot

To relieve lower back pain, some patients choose to receive epidural steroid shots -- that is, injections of steroids to the space surrounding the spinal cord. But in addition to mixed reports on their efficacy (some studies show only 60 percent of people experience a benefit from such treatments), steroids could lead to other health risks, such as raised blood sugar among people with diabetes, slow wound healing, and acceleration of bone disease in older women. The Mayo Clinic also points out that the steroids could weaken muscles and spinal bones.

But now, a new review of the research in the journal Anesthesiology suggests the steroids in the steroid shots may not be alleviating the back pain, but rather the injection of any fluid into the space around the spinal cord.

While researchers say it's too early to say that injections of steroids are useless for treating back pain and to recommend against their use, they do say that "our evidence does support the notion that, for now, reducing the amount of steroids for patients at risk may be advisable," study researcher Mark C. Bicket, M.D., an anesthesiology and critical care medicine chief resident at The Johns Hopkins Hospital, said in a statement.

The review, which looked at 43 studies conducted through October 2012 that included 3,641 patients, compared the efficacy of epidural steroid injections with other kinds of injections, but epidural and intramuscular (when it's injected into muscle by the spinal canal).

Researchers found that epidural steroid shots were more than twice as likely to work at alleviating lower back pain, compared with shots of other products -- whether it be saline, steroids or local anesthetics -- directly to the muscle near the spinal canal.

But they also found that epidural injections of any kind were twice as good as injections to the muscle.

Study author Steven P. Cohen, M.D., an anesthesiologist at Johns Hopkins, added that past mixed research on efficacy of steroid injections may be because "those studies were actually comparing two treatments, rather than placebo versus treatment ... Researchers may be wasting millions of dollars and precious time on such studies."