Ceramic Smooths Out Hip Implants

New devices expected to last longer with fewer problems

FRIDAY, Nov. 15, 2002 (HealthDayNews) -- Luke Pascale is an Indiana father of four who runs two pizza restaurants and tries to exercise regularly.

However, last year he was suffering so much hip pain that he could no longer enjoy long bike rides with his wife.

These days, he's pain-free. He underwent total hip replacement during the summer after enrolling in a clinical trial for a new hip-implant device that uses all ceramic materials, rather than the traditional plastic and titanium.

"I could hardly walk for five minutes without having pain or having to stop," Pascale recalls in a statement. "Now I can go a couple hours on the bike without stopping."

Experts studying the new devices, not yet approved by the U.S. Food and Drug Administration (FDA), say the ceramic-to-ceramic implants may last longer with fewer problems and be especially good for younger patients, who have a longer expected lifespan.

Traditional implants begin to wear down after about 15 years, says Dr. Steven Gitelis, an orthopedic surgeon at Rush Presbyterian St. Luke's Medical Center in Chicago, one of many surgeons involved in clinical trials of the new ceramic-to-ceramic implants. Tiny particles can break off from the older implant and cause problems.

"The notion of using ceramic is not new," Gitelis says. However, the ceramic used in the devices now under study, called alumina, is believed to be better suited for the implant than an older type of ceramic, called zirconia that has been studied and used in the past. (The FDA last year recalled ceramic hip-implant devices made of zirconia. The recall was triggered by a higher-than-expected fracture rate of the devices.)

In 2000, 152,000 total hip replacement surgeries were performed in the United States, according to the American Academy of Orthopaedic Surgeons. The average patient was 66 years old.

The hip joint is known as a "ball-and-socket" joint because the head of the thigh bone, or femur, moves inside the cup-shaped hollow socket, called the acetabulum, of the pelvis. A total hip-replacement implant includes three parts: the stem, which fits into the head of the thighbone and provides stability; the ball, which replaces the head of the thighbone; and the cup, which replaces the worn out hip socket.

In the clinical trials now under way, "we are looking to see if the outcomes are equal to the conventional hip implant," Gitelis says. "If this device has outcomes equal to the conventional, we believe these [all ceramic] devices will wear far less."

The ideal candidate, Gitelis adds, is a younger patient, "generally those under age 65 and in otherwise good health and active."

More than 1,400 patients have received a ceramic device in studies conducted by Wright Medical Technology in Arlington, Tenn., one of the companies involved in testing the ceramic implant, says Steve White, a company spokesman. The company has applied for FDA approval of the device.

An additional 1,100 patients have gotten a ceramic implant in trials conducted by Stryker Howmedica Osteonics of Allendale, N.J., another company seeking FDA approval.

White says the ceramic device is more expensive than the traditional implant. He couldn't say how much of that added cost would be passed on to the patient.

If approved by the FDA, the new ceramic implants "will be worth a look," says Dr. William Bargar, medical director of the Joint Replacement Center at Sutter General Hospital in Sacramento, Calif., and a spokesman for the American Academy of Orthopaedic Surgeons.

"If you need a hip now, however, I think I'd go ahead with the current technology," Bargar says.

What To Do

For information on hip implants, see the American Academy of Orthopaedic Surgeons or the American Association of Hip and Knee Surgeons.

SOURCES: Steven Gitelis, M.D., orthopedic surgeon, Rush Presbyterian St. Luke's Medical Center, Chicago; William Bargar, M.D., director, Joint Replacement Center, Sutter General Hospital, Sacramento, Calif., and spokesman, American Academy of Orthopaedic Surgeons; Steve White, spokesman, Wright Medical Technology, Arlington, Tenn.
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