Presented at the 2012 AAPM Annual Meeting « Back

Novel Interspinous Spacer for Treatment of Moderate Lumbar Spinal Stenosis: 1-Year Results of a Randomized Controlled IDE Trial

Thomas R. Haley, DO, thaley@performancespine.com¹, Christopher Dankmyer, MD¹, Larry E. Miller, PhD², Jon Block, PhD², (1) Performance Spine and Sports Physicians, P.C., Pottstown, Pennsylvania, (2) Jon E. Block, PhD, Inc., San Francisco, California

Introduction: Treatment options for lumbar spinal stenosis range from conservative care to open spinal decompression surgery. This study reports 1-year clinical outcomes in patients with moderate LSS treated with an investigational (Superion) compared to an FDA-approved (X-STOP) interspinous spacer. Methods: This prospective, randomized, controlled IDE trial (NCT00692276) received IRB approval and enrolled 87 patients (mean age: 67 yr, 63% male) with moderate stenosis unresponsive to at least 6 months conservative care. Patients were treated randomly with the Superion (n = 46) or X-STOP (n = 41) interspinous spacer and followed through 1 year. Results: ZCQ symptom severity and physical function scores improved significantly 26% to 31% in both groups. ZCQ patient satisfaction scores were 2.0±1.0 with Superion and 1.8±0.8 with X-STOP (p=0.34). Axial pain also decreased significantly in both the Superion and X-STOP group. Extremity pain decreased from 60±25 mm at pretreatment to 21±31 mm at 1 year with Superion (p<0.001) and from 65±27 mm to 23±29 mm with X-STOP (p<0.001) (p=0.76 between groups). Back function similarly improved with Superion (36±13% to 21±18%; p<0.001) versus X-STOP (40±13% to 26±16%; p<0.001) (p = 0.84 between groups). Conclusions: Midterm results suggest that the Superion Interspinous Spacer provides similar benefit as X-STOP in alleviating pain and improving back function in patients with moderate LSS.

Funding: Vertiflex, Inc., San Clemente, California