A saline injection in the spine could be more effective than steroids for treating lower back pain, a new study has revealed.
Spinal pain is a leading cause of disability in the industrialised world and epidural steroid injections - the most common nonsurgical treatment - have been the standard treatment for more than 50 years.
Yet the alternative spinal injection in the space around the spinal cord may provide better relief than steroids which can have adverse side effects.
Steroids raise blood sugar in diabetic back patients, slow the healing of wounds and accelerate bone disease in older women, the Johns Hopkins University study found.
Professor of Anaesthesiology Steven Cohen at the U.S. university said: 'Just injecting liquid into the epidural space appears to work.
'This shows us that most of the relief may not be from the steroid, which everyone worries about.'
The research was prompted when more than 740 people in 20 U.S. states became ill with fungal meningitis and 55 people died after getting epidural injections of contaminated steroids last year.
Although better oversight might reduce that risk, patients can only get a limited number of steroid injections each year, even if their pain returns.
Professor Cohen said it was too soon to recommend that patients stop receiving epidural steroids, but added that their analysis also suggests that smaller steroid doses can be just as beneficial.
Fellow researcher Dr Mark Bicket said larger scale studies were needed to determine whether steroid alternatives can be just as helpful for back pain patients.
He said: 'Our evidence does support the notion that, for now, reducing the amount of steroids for patients at risk may be advisable.'
The review covered medical records of 3,641 patients from 43 studies conducted in October 2012 and compared epidural steroid injections to other sorts of epidural and intramuscular injections.
Professor Cohen said the new analysis suggested that decades of mixed results of research on epidural steroid injections may have been due to the use of saline or anaesthetic injections as the comparison 'placebo' treatment.
He said: 'It's likely that 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.'
The findings are published in the latest edition of the journal Anaesthesiology.