A double-blind, randomized, prospective study of epidural steroid injection vs. the mild® procedure in patients with symptomatic lumbar spinal stenosis

Abstract

Background: Epidural steroid injections (ESIs) are commonly used to treat low back pain, including symptomatic lumbar spinal stenosis (LSS). Reports on LSS treatment with ESIs have not differentiated between neurogenic claudication, which is believed to result from nerve root compression, and lumbar radicular pain, thought to be caused by inflammation. While there is overlap between these groups, the clinical relevance of ESI treatment cannot be generalized between these 2 distinct diseases with completely different pathophysiological causes.

Methods: This was a double-blind, randomized, prospective study of ESI vs. the mild procedure in patients with symptomatic LSS, conducted at a single pain management center. Patient reported outcome measures included Visual Analog Scale, Oswestry Disability Index, and Zurich Claudication Questionnaire (ZCQ) patient satisfaction.

Results: Thirty-eight patients were randomized into 2 treatment groups, 21 in mild and 17 in ESI. At 6- and 12-week follow-up, patients treated with mild reported significantly greater pain decrease over time (P < 0.0001), and significantly greater functional mobility improvement over time (P < 0.0018) than ESI patients. At week 6, mild ZCQ patient satisfaction score of 2.2 indicated a higher level of satisfaction than for ESI with a score of 2.8. In addition, 12-week ZCQ satisfaction score was 1.8, demonstrating sustained near-term satisfaction in the mild group. No major mild or ESI device or procedure-related complications were reported.

Conclusions: This study demonstrated that in LSS patients suffering with neurogenic claudication, mild provides statistically significantly better pain reduction and improved functional mobility vs. treatment with ESI.

Trial registration: ClinicalTrials.gov NCT00995371.