Spinal stenosis is a narrowing of the canal that encases and protects the spinal cord. The condition causes the spinal nerves in the affected area to be pinched or compressed. Patients may complain of pain in the low back and/or legs after walking or standing for a period of time. Pain may become progressively worse with prolonged standing or walking and ease after sitting or bending forward.

The American Association of Neurological Surgeons estimates about 400,000 Americans have lumbar spinal stenosis (affecting the lower back). The condition is more common in women and is usually diagnosed in adults in their 50s and 60s. Most often, spinal stenosis is the result of degenerative changes in the spine, like from osteoarthritis or a herniated disk.

Treating Spinal Stenosis: Nonsurgical Options

Many patients with spinal stenosis can be treated without surgery. Non-steroidal anti-inflammatory medications can help reduce pain, swelling and inflammation. Other analgesics (like acetaminophen) only reduce pain. Heat or ice, massage and electrical stimulation may improve symptoms. Doctors may also recommend physical therapy, bracing and exercises to strengthen the spine and improve endurance and flexibility.

If pain is severe, doctors may offer an injection of corticosteroids into the spinal fluid (an epidural injection). The treatment can directly reduce inflammation at the site of the problem.

Surgical Options

When conservative treatments fail to relieve symptoms, doctors may refer a patient for surgery. In decompression surgery (also known as a laminectomy), doctors relieve pressure on the spinal nerves by opening up the narrowed area of the spinal canal. The procedure involves removing small areas of bone or protruding material from a herniated intervertebral disk.

In some cases, patients may also require fusion to stabilize the affected area of the spine. A small amount of bone is taken from elsewhere in the body (often the hip) and placed into the space between the vertebrae. Rods and screws may be inserted into the bones to hold the vertebrae in place. Once the site heals, the upper and lower vertebrae in the affected space are permanently fused into one unit to stabilize the spine (i.e., prevent the vertebrae from slipping out of position and pressing on the spinal nerves).

A New Treatment

According to the American Academy of Orthopaedic Surgeons, more than 325,000 spinal fusions were done in 2003. About 162,000 were on the lower spine. While the treatment is usually very successful, it has a limitation. Since the affected vertebrae are fused into one unit, the patient loses mobility in that area of the spine.

Researchers are now testing new devices for patients with spinal stenosis, called the Total Facet Arthroplasty System® (TFAS®) (made by Archus® Orthopedics). TFAS replaces the facet joints in the spine (the tiny joints between the vertebrae that enable the spine to bend). Patients still have decompression surgery. But instead of fusion, the TFAS is inserted between the vertebrae. The system stabilizes the spine and enables patients to maintain near-normal bending motion.

Barton Sachs, M.D., an Orthopedic Surgeon with Texas Back Institute, says recovery time after TFAS is quick. Patients are able to get back to normal activity in about half the time of a spinal fusion because they don't need to wait for a fusion to heal.

Currently, TFAS is in clinical trials and is not yet approved for general use. (A list of trial sites is included at the end of the summary.) To be considered for the trial, patients must have moderate to severe spinal stenosis at a single level in a section of the lower spine. Participants will be divided into two groups. All will receive decompression surgery. Then, one-third will have standard fusion and two-thirds will receive the TFAS. Patients with osteoporosis or metabolic bone disease are not eligible for the trial.

TFAS Trial Sites:

Loma Linda University Healthcare, San Bernardino, CA

Panorama Orthopedics and Spine Center, Golden CO

William W. Backus Hospital - Norwich Orthopedic Group, Norwich, CT

Florida Spine Institute, Clearwater, FL

Florida Orthopaedic Institute, Tampa, FL

The Disc Replacement Center of North Florida, Tallahassee, FL

Chicago Institute of Neurosurgery, Chicago, IL

Brigham and Women's Hospital, Boston, MA

Northern Rockies Neurosurgeons, PLLC, Billings, MT

Southern New York NeuroSurgical Group, P.C., Johnson City, NY

Advanced Neurosurgery, Inc., Kettering, OH

Medical University of South Carolina, Charleston, SC

Johnson City Medical Center, Johnson City, TN

Vanderbilt University Medical Center, Nashville, TN

Texas Back Institute, Plano, TX

Evergreen Medical Center, Kirkland, WA

Inland Neurosurgery and Spine, Spokane, WA

Seattle Neuroscience Specialists, Seattle, WA

(Other sites are being opened. See the company's website for the most up-to-date information: http://www.facetjointreplacement.com.)

For information about the procedure, or referral to the nearest study site, log onto http://www.facetjointreplacement.com. Information about the clinical trial is also available from http://www.clinicaltrials.gov. Type the trial identification number in the search box to access the information - NCT00418197.

For general information on spinal stenosis:

American Academy of Orthopaedic Surgeons, public website

American Association of Neurological Surgeons

American College of Rheumatology

Arthritis Foundation

National Institute of Arthritis and Musculoskeletal and Skin Diseases