The clinical study described herein aims to compare surgical outcomes of X-STOP® Interspinous Process Decompression® (IPD) system implantation and conventional laminectomy in subjects requiring surgical intervention due to symptoms of lumbar spinal stenosis (LSS) and a confirmed diagnosis on MRI, X-ray or CT. Patients with LSS meeting entry criteria will be randomized to either X-STOP® IPD or laminectomy treatment. Patients will remain blinded to the procedure received. The primary study outcome is group differences in the Zurich Claudication Questionnaire (ZCQ) at 12 months post-operative. In addition, each subject will undergo follow-up assessment at 2 weeks and 2, 12 and 24 months post-operative. The secondary objective is to compare safety profiles and the radiographic outcomes between groups using pre- and post-operative MRI and flexion/extension X-rays, to measure changes in canal and neuroforaminal cross sectional areas and spinal stability, respectively.
To determine if the effectiveness of the X-STOP® implant is equivalent (non-inferior) to that of conventional laminectomy in patients with lumbar spinal stenosis as measured by the Zurich Claudication Questionnaire.