Spinal stenosis is a narrowing of the spinal canal at one or more points along the spine. This puts pressure on the spinal nerves in the affected areas, causing leg pain or cramping, numbness and tingling in the buttocks or legs, muscle weakness in the legs, and, sometimes, loss of bladder or bowel control.
The pain, numbness and tingling occur while walking or standing and are typically relieved by sitting or bending forward (which opens the space in the spinal canal and takes pressure off the nerves). For some, the symptoms can be very debilitating and limit the ability to walk or perform certain activities.
Initially, doctors may try to treat spinal stenosis with conservative measures, like physical therapy, anti-inflammatory medications, steroid injections and spinal manipulation. If these treatments don’t provide relief, surgery may be recommended. The goal of surgery is to take the pressure off the spinal nerves.
There are two main types of surgery for treatment of spinal stenosis. A laminectomy, sometimes referred to a decompression surgery, is the removal of the structures pressing on the spinal nerves (like bone spurs, bone, or ligaments). If the spine isn’t stable, spinal fusion is needed. Pieces of bone are taken from the hip and placed in between the affected vertebrae. As the fragments heal, they fuse the two vertebrae into a solid bone. Sometimes tiny rods and screws are placed to hold the vertebrae in place while healing occurs. Pressure is taken off the spinal cord because no movement is possible in that area.
Spinal fusion is a very common procedure. Researchers estimate about 100,000 spinal fusions are performed annually in Americans over 60.
Doctors are now testing a new device for treatment of moderate spinal stenosis, called the Superion™ Interspinous Spacer. Currently, it’s being studied for stenosis in the lower section (lumbar area) of the spine. Placement of the device is performed using minimally invasive surgery and, typically, general anesthesia.
A small incision is made into the back. Through the incision, the surgeon places a series of dilators (tubes of increasing diameter that stretch the space and give more room for the surgeon to work). The Superion Interspinous Spacer is inserted through the dilator and placed between the spinous processes (the bony structures along the back of the spine). Then the dilator is removed and the tiny incision closed. The Superion device works like a jack to keep the space open for nerve endings in the spinal canal and reduce the risk for symptoms of spinal stenosis.
Currently, the Superion Interspinous Spacer is an experimental device. It is being tested in a clinical trial at that will eventually include up to 35 sites across the country. In the trial, Superion is being compared to another type of interspinous spacer, called the X-STOP® IPD® Device. Half the patients in the study will get the Superion and half will get the X-STOP.
The Superion study is still enrolling participants and expected to run until June 2011. For information about the clinical trial, or to find the closest study site, go here. You can also get information by going to the company’s website or phoning their call center at (888) 978-8391 (888-9-STUDY-1).