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UCH Spine Center Reports Positive Patient Outcomes for Interspinous Spacer

A new approach to spinal stenosis surgery

A new medical device called an "interspinous spacer" is helping ease lower back pain for a growing number of patients at University of Colorado Hospital's Spine Center and elsewhere.

Lumbar spinal stenosis, or LSS, is diagnosed roughly 700,000 times a year in the United States. It is a result of expanding bone spurs and disc cartilage between vertebra, which narrow the spinal canal. This narrowing, or stenosis, can impinge on the spinal cord as well as nerve roots exiting to the legs.

Many aching backs. LSS symptoms include dull or aching back pain spreading to the legs; numbness and “pins and needles” in the legs, calves and rump; weakness and degraded physical balance and lessened physical endurance. They tend to flare when a person is in a standing position. Such symptoms, in turn, can limit a patient’s physical activity and contribute to obesity, depression and other psychological issues and general physical deterioration, physicians say.


To date LSS patients who have received
the interspinous spacer have reported
significant pain relief.

Studies have shown that roughly one in 10 people end up with such symptoms, making lumbar spinal stenosis the most common reason for spine surgery among older people in the United States.

A third treatment option. There have traditionally been two main avenues for treating LSS. One focused on physical therapy, anti-inflammatory drugs and epidural injections. The other involved major surgery called a laminectomy, or “unroofing” of the vertebral bone and ligaments to take pressure off the spinal cord and nerves. Surgery also often involved fusing vertebra with titanium screws to add stability. The interspinous spacer offers another less invasive option for some patients.

How it works. The titanium device, approved by the U.S. Food and Drug Administration in November 2005 for use in LSS patients aged 50 or older, consists of two flanking “wings”connected by a central bar, giving the loose impression of an automotive spoiler.

Surgeons remove one wing, insert the bar between two spinous processes (the protrusions making up the “bumps” in the backbone), and lock the second wing down. The bar then prevents the vertebra from pressing as closely together. A patient can have one, two or even three spacers inserted, says Vikas Patel, MD, a UCH Spine Center surgeon, who has done about 50 such procedures in the past two years.

An outpatient procedure. Unlike a laminectomy, it’s an outpatient procedure, and can be done under local or general anesthetic, Patel says. He adds that within about 10 days – the time it takes the incision to heal – the patient has no medical restrictions.

The interspinous spacer provides a third option, says Patel. "I think it's a great technique for the right patients," he remarks.

Evalina Burger, MD, vice chair of the University of Colorado Denver School of Medicine's Department of Orthopedics and a senior orthopedic spine surgeon at the Spine Center, noted that the spacer "seems to make a significant difference in terms of immediate relief" for the patients who get the device.

Waiting for long-term data. Dr. Burger notes that because the interspinous spacer is a new device, its effectiveness at reducing lower back pain over time has yet to be determined.

Still, as Dr. Patel says, the spacer "allows patients a minimally invasive alternative [to traditional treatments] that does not require general anesthesia, and it's an option for patients who would otherwise be too sick or medically compromised to have surgery."


This page is adapted from a story written by Todd Neff that appeared in the UCH Insider, the hospital's candid e-newsletter. The Insider, which is published biweekly, is available to people outside the hospital via a free e-mail subscription. Tyler Smith ( is managing editor of the Insider.

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