Hope for Amputees: Preventing Amputation

by Food and Drug Administration (FDA)

"Only 70 people have ever done anything like it before," Barr said. "There've been more people in outer space than have made this trip."

What makes it more extraordinary is that Barr, 41, is a double amputee. Fighting in Angola in 1981, he lost one leg above the knee and the other below the knee. But that hasn't kept him from riding a two-wheel 1972 Harley Davidson and writing a book about his around-the-world motorcycle trip.

And that is not all. Barr is one of only a handful of double-amputee parachutists who jump with special prosthetics. And he walks 3 or 4 miles a day and mows his own grass.

Advances in prosthetics, and the example set by amputees such as Barr, have shown more and more people that an amputation does not always mean confinement to a wheelchair. At private companies and key centers such as Northwestern University in Chicago and the University of Utah at Salt Lake City, research that sounds like something out of "The Six Million Dollar Man" could give amputees even more control over artificial limbs.

Physical therapist Marie A. Schroeder, chief of the Food and Drug Administration's restorative devices branch, explains that FDA regulates prostheses, but manufacturers do not have to undergo a full review for each new device. Instead, they must register the products and keep a record of any complaints.

"But if there's a significant change in the technology, we could get involved," Schroeder said.

For instance, she said, her branch has seen some interest in implantable electrodes for stimulating muscles in spinal cord injury cases. Such devices would require review by FDA.

Some innovators are also exploring ways to use computers to design and manufacture custom prostheses, to attach muscles directly to a prosthesis, to develop powered fingers with microelectronics, and even to use brain waves to power prostheses.

For thousands of years, inventors have tried to replicate what nature cannot replace. Prostheses have been used since at least 300 B.C., when crude devices consisting of metal plates hammered over a wooden core, were attached to an amputated limb.

Advances in the science of prosthetics burgeon during and immediately after wars, when large numbers of people need to be fitted with artificial limbs. The technology of modern prosthetics has changed little since shortly after World War II.

"There's a real need for revolution in design," said Giovani M. Ortega, research and development project manager at Sabolich Prosthetics & Research in Oklahoma City, Okla., a division of NovaCare. "The systems that we have, have been around for a long time, and at best there have been only improvements. As far along as we've come, we're still far behind many other industries in terms of implementing new technologies."

Estimates of the amputee population in the United States vary widely, from fewer than 400,000 to more than 1 million. About 9 out of 10 amputations involve the leg, from the foot to above the knee.

Three-quarters of all amputations are the result of disease, often cancer or peripheral vascular disease. The latter is a narrowing of the arteries in the extremities that is often associated with diabetes. Most other amputations are the result of workplace or automobile accidents. And a small fraction, perhaps 3 percent, are due to birth defects that constrict bone growth.

Preventing Amputation

Because so many amputations result from disease, considerable attention has been paid to prevention. For example, the American Diabetes Association recommends people stop smoking, which can speed the progress of peripheral vascular disease. Patients with diabetes should monitor their blood glucose levels carefully, eat a healthy, balanced diet, see their doctors regularly, control their weight, and check their feet each day for small cuts or blisters.

Electric blankets and heating pads carry warning labels that say people with diabetes should not use them without talking to their doctors first. This is because people with diabetes may lose sensation in their limbs. Patients can be seriously burned by an electric blanket or heating pad because they cannot feel how hot it really is.

Patients are also advised to develop an exercise plan after consulting with their doctors. Regular exercise maintains strength, flexibility, and blood flow to damaged areas and can help control pain. However, it's important not to stress the legs, feet or joints. Some good exercises are bicycling or easy rowing on a rowing machine. Swimming and aqua aerobics are also good choices.

"We know of many things that can help people avoid amputation, but unfortunately, it's no fun to do daily foot care or wear only proper fitting, well-designed shoes," said Jennifer Mayfield, M.D., chairwoman of the association's Foot Care Council. "Everybody keeps waiting for a magic bullet, and that would be nice, but it's not coming anytime soon."

Richard J. Gusberg, M.D., chief of vascular surgery at Yale University, said one of the first signs of peripheral occlusive disease is claudication, an aching, tired feeling in the leg muscles when they are exercised.

"The vast majority of people with claudication remain stable, or nearly stable, for an indefinite period of time," Gusberg said. In most cases the progress of the disease can be slowed if people control the risk factors, which includes reducing blood pressure, controlling their diabetes through diet or insulin, and reducing cholesterol levels. Regular exercise has also proven effective because it can strengthen circulation, he said.

The drug Trental (pentoxifylline) is approved by FDA for people with peripheral artery disease. Its use can decrease the thickness and stickiness of blood, and can reduce the deformities of red blood cells, so the blood can get through the narrowed arteries, but it is not effective in all patients, Gusberg said. The use of other drugs in treating occlusive disease has largely been abandoned, he said.

If the disease progresses, the patient might develop gangrene, or ulcers in the leg, as blood flow is reduced.

"When people get to that stage, most of them need to be evaluated for a bypass operation," Gusberg said. Replacing the arteries in the lower leg is effective for five years or more in 70 to 80 percent of cases.

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.