Glucocorticoid injections may not help in lumbar spinal stenosis

Epidural injections of glucocorticoids plus lidocaine to treat spinal stenosis performed no better than injections of lidocaine alone in a new trial.

Researchers conducted a randomized, double-blind, multisite trial to gain more data on the effectiveness of epidural glucocorticoid injections for treating symptoms of lumbar spinal stenosis. Patients who were at least 50 years old and had lumbar central spinal stenosis and moderate to severe leg pain and disability were assigned to receive either epidural injections of glucocorticoids plus lidocaine or epidural injections of lidocaine alone. The primary outcomes, which were scores on the Roland-Morris Disability Questionnaire (RMDQ) and patient self-rating of leg pain intensity, were measured 6 weeks after randomization. RMDQ scores are measured on a scale of 1 to 24, with higher scores indicating more disability, and leg pain intensity was measured on a scale of 0 (no pain) to 10 (worst pain imaginable). The study results were published in the July 4 New England Journal of Medicine.

Four hundred patients at 16 centers in the U.S. were involved in the study. Two hundred patients were randomly assigned to the glucocorticoid-lidocaine group, and 200 patients were randomly assigned to the lidocaine-alone group. The mean age was approximately 68 years in both groups, and most patients (55%) were women. Small between-group differences in RMDQ score and leg pain intensity were seen at 3 weeks (average treatment effect, −1.8 points and −0.6 point, respectively; P<0.001 and P=0.02). At 6 weeks, both groups showed improvement in the RMDQ score from baseline, but no significant between-group difference was seen (−4.2 points in the glucocorticoid-lidocaine group and −3.1 points in the lidocaine-alone group; adjusted difference in average treatment effect, −1.0 point; P=0.07). The same was true for intensity of leg pain at 6 weeks (adjusted difference in average treatment effect, −0.2 point; P=0.48).

A statistically significant difference in RMDQ score was seen at 6 weeks after post hoc adjustment for baseline duration of pain, but it was small (average treatment effect, −1.2 points; P=0.03), and no significant difference in leg pain intensity was noted (average treatment effect, −0.3 point; P=0.32). Overall, 21.5% of patients in the glucocorticoid-lidocaine group and 15.5% in the lidocaine-alone group experienced 1 or more adverse event (P=0.08), and 67% versus 54%, respectively, said they were very or somewhat satisfied with their treatment (P=0.01).

The authors noted that some patients received transforaminal injections while others received interlaminar injections and that their study was not designed to compare the effectiveness of the 2 methods. They also noted that their study did not include a sham injection group. However, they concluded that based on their results, epidural injections of glucocorticoids and lidocaine offer no benefit compared with lidocaine alone for relieving symptoms of lumbar spinal stenosis.

The author of an accompanying editorial said that the study's results call the benefits of epidural glucocorticoid injections into question and suggested that insurance companies may want to reconsider requiring a trial of such injections before approving surgery. “On the basis of the largely negative results of the present trial and the lack of other rigorous data to support the use of glucocorticoid injections in these patients, I will remain cautious in prescribing epidural glucocorticoid injections for patients with lumbar spinal stenosis,” the editorialist wrote. “Patients should be informed that the current best available data have not provided support for a clinically significant long-term benefit overall and that complications are possible.”