For acute sciatica, a steroid injection worked no better than salt water

An ultrasound-guided caudal injection of dexamethasone did not improve disability at 3 weeks, or other outcomes up to 6 months, compared with a saline injection, in a double-blind trial of 106 adults with acute sciatica published in September 2026 in European Journal of Pain. For this kind of back pain, time and activity remain the mainstays.

Sciatica is pain that runs from the lower back down the leg, often caused by a herniated disc pressing on a nerve. Steroid injections near the spine are widely used to calm the inflammation, but their benefit is debated.

What did the trial test?

In the DEXHIA trial, 106 adults with sciatica from a herniated disc lasting less than 3 months were assigned by chance to an ultrasound-guided caudal epidural injection (through the base of the spine) of 16 mg of dexamethasone diluted in saline, or saline alone. 53 people were in each group, and neither patients nor assessors knew which they received. The main outcome was the change in the Oswestry Disability Index, a measure of how back pain limits daily life, at 3 weeks.

What did the study find about back pain?

• Disability improved in both groups, by 9.5 points with dexamethasone and 13.8 points with saline, with no significant difference.
• No relevant secondary outcome, such as leg pain, back pain or quality of life, differed at 3 weeks, 3 months or 6 months.
• During follow-up, 34 people in the dexamethasone group and 30 in the saline group had a second injection.
• Lumbar surgery was needed by 10 people with dexamethasone and nine with saline.
• Injection side effects were mild but more frequent with dexamethasone.

Why does this matter?

Many people with sciatica receive epidural injections. This well-designed trial adds evidence that, at least with this approach and drug, the steroid itself doesn’t add benefit. The improvement seen in both groups reflects that acute sciatica often gets better on its own over weeks.

How solid is this evidence?

It’s good. Mongevity rates it B on our A-to-E scale: a double-blind, placebo-controlled randomized trial. Limits: it was relatively small, it tested one route (through the base of the spine) and one non-particulate steroid, and many participants later had a non-blinded injection, which complicates long-term comparisons.

What are the open questions?

It’s unclear whether other routes, such as injections closer to the affected nerve root, or other steroids give different results.

What does this mean for you?

If you have sciatica, staying as active as you can, short-term pain relief and physiotherapy are usually the first steps, and many people improve within weeks. Ask your doctor about the expected benefit before an injection. Seek urgent care for leg weakness, numbness in the groin area or loss of bladder or bowel control.

How do I explain this at dinner?

People with a pinched nerve causing leg pain got either a steroid shot near the spine or a shot of salt water. Both groups improved about the same, showing that much of the recovery comes with time. A good question for the table: how do we know a treatment works and not just time?

In one sentence: in acute sciatica from a herniated disc, an ultrasound-guided caudal injection of dexamethasone conferred no clinical benefit over saline placebo.