Rationale, design and clinical performance of the Superion® Interspinous Spacer: a minimally invasive implant for treatment of lumbar spinal stenosis.

Lumbar spinal stenosis is a progressive degenerative condition that manifests as low back pain with neurogenic claudication as a cardinal clinical feature. Although mild radicular symptoms can often be successfully treated with conservative care, management of lumbar spinal stenosis grows increasingly difficult as symptoms worsen. No satisfactory nonsurgical treatments exist to manage moderate radicular symptoms and, therefore, these patients are faced with the decision of continuing ineffective conservative options or opting to undergo invasive decompressive spine surgery. The Superion(®) Interspinous Spacer (Vertiflex, Inc., CA, USA) was developed specifically to fill the therapeutic void between conservative care and surgical decompression. The Superion device is a titanium implant that is delivered percutaneously and deployed between the spinous processes at the symptomatic vertebral levels. The Superion device improves radicular symptoms by limiting spinal extension and, consequently, minimizing impingement of neural and vascular elements. This article describes the rationale for and the design of the Superion device and summarizes initial clinical results with this novel, minimally invasive interspinous spacer.