P20. Positional MRI changes in the lumbar spine following insertion of a novel interspinous process distraction device

BACKGROUND CONTEXT: Clinical, radiologic, and cadaveric studies have demonstrated reduction in area of the dural sac and exit foramina as the lumbar spine moves from flexion into extension. Patients with spinal stenosis develop symptoms of radiculopathy and/or neurogenic claudication in erect or extended postures which are relieved by sitting or stooping. Clinical studies on the X-Stop device have shown improvement in the claudication outcomes. The device can be implanted under local anaesthetic, avoiding the high morbidity or mortality associated with spinal decompressions and/or fusions.