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Reference: N Engl J Med 2014 Jul 3;371(1):11 (level 2 [mid-level] evidence
Although epidural steroid injections are commonly used in patients with spinal stenosis, the evidence supporting its use is limited. The most recent North American Spine Society (NASS) guideline for degenerative lumbar spinal stenosis states that interlaminar epidural steroid injections are suggested to provide short-term symptom relief (2 weeks to 6 months) in patients with neurogenic claudication or radiculopathy (Spine J 2013 Jul;13(7):734). A recent randomized trial compared epidural steroid injection with lidocaine to lidocaine alone at 3 and 6 weeks in 400 patients with spinal stenosis and moderate-to-severe leg pain and disability.
Patients in the steroid group received 1 to 3 mL of triamcinolone (60-120 mg), betamethasone (6-12 mg), dexamethasone (8-10 mg), or methylprednisolone (60-120 mg) at the discretion of the treating physician. Disability was assessed with the Roland-Morris Disability Questionnaire (range 0-24), and leg pain was assessed with the Brief Pain Inventory scale (range 0-10). At baseline, the duration of pain was higher in glucocorticoids plus lidocaine group compared to the lidocaine alone group (p = 0.02). Patients receiving epidural steroids did not achieve a clinically significant improvement in mean pain or disability scores at 3 weeks compared to those not receiving steroids. In addition, there were no clinically or statistically significant between-group differences in these outcomes at 6 weeks. Furthermore, there were no significant differences in the proportions of patients with ≥ 50% improvement in disability or pain scores at 6 weeks. However, in a post-hoc analysis adjusting for baseline pain duration, patients receiving steroid plus lidocaine had a small but significantly greater reduction in disability score at 6 weeks compared to those receiving lidocaine alone (p = 0.03).
The results of this trial are consistent with another recent randomized trial evaluating the addition of betamethasone to lidocaine epidural injections in patients with spinal stenosis (J Spinal Disord Tech 2012 Jun;25(4):226). That trial also found no improvement in disability or pain scores at 12 weeks to 1 year in patients receiving steroid plus lidocaine, but also had potential confounding due to imbalanced patient characteristics at baseline. The results of these two recent randomized trials suggest that any improvement in disability or pain does not persist beyond 6-12 weeks. Moreover, any benefit observed prior to that time must be weighed against an increased risk of adverse events, including potential product contamination, temporary alterations in glucose control, and steroid-induced fluid retention.
For more information see the Epidural steroid injection topic in DynaMed.
Special thanks to Janine Knudsen and Nicole Jackson of Harvard Medical School for their contributions to this week’s article.