FDA OKs Hip Resurfacing System

Metal Devices Used to Replace Parts of Damaged Hip Joint

From the WebMD Archives

May 11, 2006 -- The FDA has approved a hip resurfacing system for people with hip damage.

The product is called the Birmingham Hip Resurfacing (BHR) System. It's designed to relieve hip pain and improve hip function by replacing parts of the hip joint while conserving more bone than in traditional hip replacement.

The system is made by Smith & Nephew Inc. of Memphis. A Smith & Nephew news release notes that the system is the only FDA-approved hip resurfacing system in the U.S. It was first introduced in July 1997 in the U.K. and has now been implanted in more than 60,000 patients in 26 countries.

Smith & Nephew says it will train 50 U.S. surgeons in the first phase of the system's U.S. introduction. "Training will be provided in the U.S. and Europe, with the first U.S. surgeries expected to take place this summer," states Smith & Nephew's news release.

How It Works

The system has two parts: a metal cup that replaces the damaged surface of the hip socket and a cap that covers the resurfaced ball-shaped bone at the top of the thigh (femoral head). The cap has a small stem that is inserted into the thigh bone.

"The cap moves within the cup," says the FDA. "The surfaces that rub against each other (the bearing couple) are made from highly polished metal."

"The BHR System relieves hip pain and improves hip function by replacing the parts of your hip that have been severely damaged by degenerative joint diseases," says the FDA. Those degenerative joint diseases include osteoarthritis and rheumatoid arthritis.

The FDA says that the BHR System is "intended for patients who, due to their relatively younger age or increased activity level, may not be suitable for traditional total hip replacement due to an increased possibility of requiring future hip joint revision."

Continued

Not for All Patients With Hip Problems

The FDA notes that the BHR System "should not be used" in patients who:

  • Have an infection of the body or blood.
  • Have bones that aren't yet fully grown.
  • Have conditions that will prevent the artificial hip joint system from remaining stable.
  • Have conditions that may prevent following instructions during the recovery period.
  • Have bones that aren't strong enough or healthy enough (such as osteoporosis or family history of severe bone loss).
  • Are female and of childbearing age. "It is unknown whether metal ions released by the device could harm an unborn child," says the FDA.
  • Have a kidney with significantly impaired function. "The patient will need testing before and/or after surgery to test the kidneys," states the FDA.
  • Have had reactions to wearing metal jewelry (metal sensitivity).
  • Have a suppressed immune system due to diseases such as AIDS or are receiving high doses of corticosteroids.
  • Are severely overweight.

Company's Cautions

The Birmingham Hip Resurfacing System web site states that the resurfacing system "has been in clinical usage for 8.5 years in its current form, during which time patient results have been at least as good as conventional hip replacement in the indicated age group.

"But long-term results of this procedure are not yet known, and the usual risks associated with any hip replacement apply, including infections, damage to blood vessels, dislocation of the hip, thrombosis, anesthetic risk, and your doctor may inform you of other potential risks," states the product's web site.

"Metal on metal hip resurfacing is also associated with an increase of metal ions in the blood and urine," the web site notes. "All evidence to date has shown no correlation with metal ions with the Birmingham Hip Resurfacing System and any health problems. More studies are being done on the effect of metal ions in pregnancy and in patients with kidney disease.

"Most doctors would suggest that metal on metal devices should not be used in these two groups," states the web site.

WebMD Health News Reviewed by Louise Chang, MD on May 11, 2006

Sources

SOURCES: FDA: "New Device Approval: Birmingham Hip Resurfacing (BHR) System - P040033." News release, Smith & Nephew. Birminghamhipresurfacing.com: "Birmingham Hip Resurfacing System Risks." Associated Press.

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