Video presented by Jeffrey Spivak, MD
This video accompanies the article: Interspinous Process Spacers.
What is Spinal Stenosis and Spinous Processes
What spinal stenosis is is a narrowing of the spinal canal and that’s behind the vertebrae and the discs, between the joints called the facet joints, and so if there’s arthritis of the facet joints or the discs and bone spurs form, there’s a narrowing of that spinal canal and within that is all the nerves. So if there is narrowing and pressure on the nerves, patients will often have pain in the back radiating down one or both legs as they stand or walk. That’s very typical and that process and condition is called lumbar spinal stenosis. A typical treatment for spinal stenosis for many, many years has been an operation called a laminectomy, where bone is removed from the spinal canal, sort of a Roto Rooter of the spinal canal, in lay terms. And while we are able to do that and successfully protect the nerves, there are consequences of doing that. We’re moving some stabilizing elements in the back of the spine potentially or creating more pain and disability later on if stenosis recurs. The interspinous process spacers look to in a more minimally invasive way. The spinous process is what we’re talking about are those points when you feel down the back, you can feel bumps in your lower back and you feel the bones of the vertebrae and those tips are what we’re talking about – the spinous processes. So they’re pretty close to the skin. So we can do a relatively minimally invasive procedure just to hold open those spinous processes and in the process of doing that, that indirectly opens up the canal for the spine without actually opening it directly with surgery and removing bone and arthritis tissue. So it helps to afford the same relief in many patients.
Interspinous Process Spacers for Spinal Stenosis Treatment
One of the newer types of treatment for spinal stenosis is the use of devices that go within and between the spinous processes and the general category of this is called interspinous process spacers. It’s a newer category of device, only one device is approved for use currently in the United Stages, although there are others in development and being tested. The theory behind it is that by pressing open the spinous processes in the back of the spine, you actually make a larger room for the nerves behind the spine running behind the vertebrae and without any direct surgery to the nerves or the common procedure, called a laminectomy, but just by holding open the spinous processes, it simulates a position of sitting or laying down where many patients are comfortable so even when they stand or walk, the spine assumes the position as though they were still sitting and so they can walk now without difficulty. These are best used for patients with spinal stenosis who do have pain in an activity-related standing or walking position that’s relieved by bending forward or by sitting down. Currently, the device that’s available for use is called the X-Stop and this is a spacer, a block of metal currently, that’s placed between the spinous processes through a very small minimally invasive procedure with a small incision in the back. It's often done outpatient or with just a short hospital overnight stay and patients are able to be up and walking immediately after and will often notice as soon as they are up and walking that they can walk further and without the leg pain they were having. The newer devices that are being tested; one is called the Coflex device. This is currently in clinical trials looking at stabilizing the vertebrae as well. While this device goes between the processes of the spine, it also directly connects to the processes and can be done along with a microlaminectomy procedure in order to directly open up the spaces for the nerve channels and so this could be useful for patients who even have pain in the sitting position or more constant pain because it does provide a direct decompression of the nerves in addition to stabilizing the spine.