Teens: Correcting the Curved Spine of Scoliosis : Surgery

by Food and Drug Administration (FDA)

(Page 2 of 2)

Today, molded braces are available that generally don't show under clothing because they fit close and only come up to the underarms. Although underarm braces are effective for lower chest and lower back curves, a full torso brace works best for a high chest curve. Getting a young person to wear a full brace continuously isn't always successful, says Yahiro, "so it's not used as much as it could be."

An alternative treatment is stimulation of muscles alongside the spine during sleep with an electrical muscle stimulator, attached by electrodes placed on the skin. FDA approved stimulators for scoliosis in 1986.

But doctors may not want to use this alternative. One study, sponsored by the Scoliosis Research Society, reported success with bracing, but not stimulation. The study was summarized in the fall-winter 1993 newsletter of the National Scoliosis Foundation, Inc.

Surgery

Of the 30,000 to 70,000 spinal surgery procedures done each year, "about a third are probably for severe scoliosis," says Mark Melkerson, who reviews the medical devices used in these procedures for FDA's orthopedic devices branch. "Depending on the patient's age," he says, "doctors usually start considering surgery when a curve exceeds 40 to 50 degrees, to prevent breathing problems."

The surgeon attaches steel rods to vertebrae at the top and bottom of the curve with hooks, screws or wires, fusing the vertebrae with bone fragments taken from the hips, ribs, or the spine itself. The healed fusions harden in a straightened position, leaving the rest of the spine flexible.

Afterwards, most patients need a brace for about six weeks.

"It usually takes three months for everything to fuse," Yahiro says. "Still, we don't say a fusion has failed until after a year."

Bradbard had corrective surgery five years ago. She'd gone back to the doctor complaining of back pain, and x-rays showed her curve had progressed to 52 degrees.

Since someone past adolescence is no longer growing, why would a scoliosis curve worsen?

Yahiro says that doctors don't yet have a complete answer, but they do know that when the spine is already severely curved, the person's weight is distributed across the abnormal curve. Over time, this stress may make the curve worse.

Before Bradbard's surgery, her right hip and ribs practically sat on each other, she says, so that she essentially had no waist. Afterwards, she suddenly was 2 inches taller, thanks to straightening with 8 inches of rods and a fused spine.

"For the longest time," she says, "I kept hitting my head when I'd get in or out of the car."

When corrective surgery is done before growth is completed, Yahiro says, the patient both gains height from the straightening and loses height from the fusions, which stop growth. The gain and loss tend to cancel each other out, he says.

Bradbard's recovery required two weeks in the hospital. But with help, she was sitting for short periods by the second day, and standing for short periods by the third. Unlike patients undergoing scoliosis surgery 15 years ago, Bradbard didn't have to lie in a body cast for months. She didn't even have to wear a brace, though it took a full year before muscle strength returned.

The lower end of her curve couldn't be corrected, or she wouldn't be able to bend at all. As a result, one leg is a quarter of an inch shorter, which she compensates for by wearing a heel lift in her shoe.

The corrective method her surgeon used is called Cotrel- Dubousset, one of several newer systems for attaching rods to the spine with hooks and screws. Researchers report Cotrel- Dubousset has less than 2 percent loss of correction, compared with 10 to 25 percent loss from the older (Harrington Rod) system. The older system allowed the hooks to rotate, so a body cast was needed to prevent their movement until fusion.

"With many of the newer systems," Melkerson says, "the hooks are rigidly fixed to resist rotation."

Like any surgery, a scoliosis operation can have complications, such as infection or a bad reaction to anesthesia. Additional risks, though rare, are possibly dislodging a hook, fracturing a fused vertebra, or damaging the spinal cord.

Someone facing possible scoliosis surgery should ask the doctor to explain how it will help and how it poses risks, which vary with the patient and method of surgery.

X-Ray Safety When teenagers have scoliosis x-rays taken, they (or their parents) can help keep their radiation exposure as low as possible by asking whether exposure-reducing techniques are being used. This is especially important for young women, because developing breast tissue has increased sensitivity to radiation, and repeated exposure in adolescence can increase the risk of breast cancer later on.

In addition to the general practice of narrowing the x-ray beam to the spinal area, the techniques are:

Attaching a special filter to the x-ray tube that absorbs much of the x-ray beam, reducing exposure by two to five times.

Using a fast screen-film combination to reduce exposure by two to six times.

Using breast shields that reduce radiation exposure to breast tissue by three to 10 times. These include the x-ray tube shield that shades the breasts; a lead vest or stole-like garment with a lead insert, worn if x-rays are taken with the patient facing the x-ray machine; or facing away from the x-ray machine so that the x-rays enter the body from behind, and the body shields the breasts.

About the Author

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FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.