Skip to main content
  • Lumbar Spinal Stenosis Treatment with an Interspinous Spacer: Preliminary Results of a Multi-Center, Randomized, Controlled FDA-IDE Trial

    Final Number:

    Reginald J. Davis MD; Jon Block PhD; Larry Miller PhD

    Study Design:
    Clinical Trial

    Subject Category:

    Meeting: Congress of Neurological Surgeons 2011 Annual Meeting

    Introduction: A therapeutic void exists for patients with moderate LSS and increasingly recalcitrant symptoms. The purpose of this clinical trial was to evaluate the preliminary safety and effectiveness of the Superion Interspinous Spacer (Vertiflex, Inc., San Clemente, CA) in patients with intermittent neurogenic claudication secondary to radiographically confirmed moderate LSS

    Methods: This multicenter, prospective, randomized, controlled, investigational device exemption trial enrolled 166 patients with intermittent neurogenic claudication secondary to moderate LSS and unresponsive to conservative care. Patients were randomized to implant with the Superion (n=80) or X-STOP (n=86) interspinous spacer. Outcomes included Condition-specific Zurich Claudication Questionnaire (ZCQ), back function with Oswestry Disability Index (ODI), back and leg pain severity with visual analogue scale (VAS), and adverse events through 6 months post-treatment.

    Results: : The proportions of patients that reported ZCQ improvements of =0.5 points were 64% and 63% for Physical Function and 75% and 53% for Symptom Severity with Superion and X-STOP, respectively. Mean Patient Satisfaction scores ranged from 1.7 to 2.0 at all follow-up visits in both groups. Median back function scores improved 48% with Superion and 38% with X-STOP (both p<0.001). ODI clinical success, defined as a =15-point improvement, was 47% with Superion and 37% with X-STOP. Both groups experienced improvements in median back (Superion 70%, X-STOP 64%) and leg (Superion 93%, X-STOP 81%) pain scores (all p<0.001). Pain clinical success, defined as a =20-point improvement on the VAS, was 60% and 50%, respectively, for back pain and 74% and 60%, respectively, for leg pain. Clinical failure, defined as reoperation, major implant- or procedure-related complication, spinal cord stimulation, rhizotomy, epidural steroid injection, or nerve block, was identified in 15% of Superion and 21% of X-STOP patients.

    Conclusions: Treatment with the Superion Interspinous Spacer results in promising early outcomes in patients with intermittent neurogenic claudication secondary to moderate LSS.

    Patient Care: This research will further the understanding of the treatment of lumbar stenosis and may result in expansion of treatment options.

    Learning Objectives: : To understand the rationale for and efficacy of interspinous spacers in patients with lumbar spinal stenosis.


We use cookies to improve the performance of our site, to analyze the traffic to our site, and to personalize your experience of the site. You can control cookies through your browser settings. Please find more information on the cookies used on our site. Privacy Policy