Epidural injections of glucocorticoids plus lidocaine proved ineffective at improving pain or function in older adults with central spinal stenosis in a double-blind, randomized, controlled trial performed at 16 medical centers across the United States.
In the LESS (Lumbar Epidural Steroid Injections for Spinal Stenosis) trial, fluoroscopically guided transforaminal or interlaminar injections of lidocaine plus triamcinolone, betamethasone, dexamethasone, or methylprednisolone failed to reduce back, buttock, and leg pain or to enhance pain-related function any better than injections of lidocaine alone, reported Dr. Janna L. Friedly of the rehabilitation medicine department at the University of Washington, Seattle, and her associates. (Lidocaine alone has never been demonstrated to offer long-term benefit, they noted.)
The use of steroid injections for spinal stenosis has risen nearly 300% over the past 20 years even though "there is little evidence of effectiveness from clinical trials." The few studies that have examined this treatment have been "small, uncontrolled, or conducted without the use of fluoroscopy," the investigators said.
In their study, patients aged 50 years and older (mean age, 68 years) who had MRI- or CT-proven central spinal stenosis were enrolled over a 2-year period and randomly assigned to receive either a lidocaine plus glucocorticoid injection (200 intervention subjects) or a matching lidocaine injection (200 control subjects) under fluoroscopic guidance. All the study participants reported back, buttock, and leg pain scores of 5 or more on a scale of 0-10 (with 10 representing the worst pain imaginable) and disability scores of 7 or higher on the Roland-Morris Disability Questionnaire (RMDQ) scale of 0-24 (with higher scores indicating greater disability).
The patients were allowed to receive a repeat injection after 3 weeks, if they wished, at the discretion of their treating physicians. The physicians also chose whether to use the transforaminal or interlaminar approach, based on a variety of clinical factors.
At 6 weeks of follow-up, patients in both the glucocorticoid-lidocaine and lidocaine-only study groups reported some improvement in pain and function, but there was no significant difference in improvement between the two groups (–4.2 points and –3.1 points, respectively, on the RMDQ). There also were no significant differences across any of the subgroups of patients studied; in particular, steroid injections were no more effective than lidocaine alone according to the duration of spinal stenosis or the type of injection approach (transforaminal or interlaminar), Dr. Friedly and her associates said (N. Engl. J. Med. 2014 July 3 [doi: 10.1056/NEJMoa1313265]).
There were no differences in the percentage of patients in either group who achieved 30% or 50% improvement RMDQ scores at either 3 or 6 weeks, nor were there any differences in "any improvement" on pain scores or in 50% improvement on pain scores at 6 weeks.
There also were no differences between the groups in scores on secondary outcome measures, including the Brief Pain Inventory, which measures pain-related interference with activities; the Swiss Spinal Stenosis Questionnaire (SSSQ), which measures pain, function, and satisfaction with treatment; the EQ-5D, which measures quality of life; or the Generalized Anxiety Disorder-7 scale.
On the Patient Health Questionnaire-8, the glucocorticoid-lidocaine group reported more improvement in depression symptoms, and on one portion of the SSSQ, more patients in the glucocorticoid-lidocaine group (67%) than in the control group (54%) reported satisfaction with treatment. This is consistent with the systemic effects of cortisol suppression and is likely to be transient, the investigators said.
The glucocorticoid plus lidocaine injections were associated with more adverse effects (21.5% of patients) than were the lidocaine-only injections (15.5%), although the difference was not significant. However, the number of adverse events reported per person was significantly higher among patients who received glucocorticoid plus lidocaine injections (0.29 vs. 0.17), they added.
This study was funded by the Agency for Healthcare Research and Quality and received no commercial support. Dr. Friedly reported no potential financial conflicts of interest; her associates reported ties to Johnson & Johnson, ArthroCare, and other companies.