Interspinous Process Decompression: Expanding Treatment Options for Lumbar Spinal Stenosis

Abstract

Interspinous process decompression is a minimally invasive implantation procedure employing a stand-alone interspinous spacer that functions as an extension blocker to prevent compression of neural elements without direct surgical removal of tissue adjacent to the nerves. The Superion® spacer is the only FDA approved stand-alone device available in the US. It is also the only spacer approved by the CMS to be implanted in an ambulatory surgery center. We computed the within-group effect sizes from the Superion IDE trial and compared them to results extrapolated from two randomized trials of decompressive laminectomy. For the ODI, effect sizes were all very large (>1.0) for Superion and laminectomy at 2, 3, and 4 years. For ZCQ, the 2-year Superion symptom severity (1.26) and physical function (1.29) domains were very large; laminectomy effect sizes were very large (1.07) for symptom severity and large for physical function (0.80). Current projections indicate a marked increase in the number of patients with spinal stenosis. Consequently, there remains a keen interest in minimally invasive treatment options that delay or obviate the need for invasive surgical procedures, such as decompressive laminectomy or fusion. Stand-alone interspinous spacers may fill a currently unmet treatment gap in the continuum of care and help to reduce the burden of this chronic degenerative condition on the health care system.

Long-term results with percutaneous interspinous process devices in the treatment of neurogenic intermittent claudication

“…In this study, only 9% of the patients had to be reoperated during the FU period, because of complications or lack of effectiveness. Similar results have been reported by Surace et al (12), describing an improvement in Oswestry Disability Index (ODI) and ZCQ scores over an 18-month FU period, and by Nunley et al (13) and by Patel et al over a 3-year FU period (14).…”

Lumbar spinal stenosis: an update on the epidemiology, diagnosis and treatment

“…Biomechanical study (94) showed the interspinous spacer significantly increased the canal area by 18%, subarticular diameter by 50%, canal diameter by 10%, the foraminal area by 25%, and the foraminal width by 41% in extension. Therefore, interspinous spacer is an alternative choice for LSS nowadays (95), it can be inserted percutaneously alone without decompression or combined with open or microsurgical decompression. The percutaneous standalone spacer implantation has advantages of being minimally invasive (96,97), however, may have high risk of unsatisfactory back pain, leg pain, quality of life and failure of implantation (98).…”

Interspinous process decompression is associated with a reduction in opioid analgesia in patients with lumbar spinal stenosis

“…There is a growing body of published literature to support the safety and effectiveness of interspinous process decompression (IPD) with stand-alone interspinous spacers in the treatment of moderate LSS. 22 , 23 Spacers provide immediate symptom amelioration by serving as a spinal extension blocker to prevent the repetitive compression of neurovascular elements during back extension that is the primary source of LSS symptoms. Clinical follow-up from a US Food and Drug Administration (FDA) investigational device exemption (IDE) randomized controlled trial of the Superion device extends to 5 years of published findings.…”