Tuesday, August 23, 2011

Hip Implant Complaints Surge, Even as the Dangers Are Studied


The federal government has received a surge in complaints in recent months about failed hip replacements, suggesting that serious problems persist with some types of artificial hips even as researchers scramble to evaluate the health dangers.

An analysis of federal data by The New York Times indicates that the Food and Drug Administration has received more than 5,000 reports since January about several widely used devices known as metal-on-metal hips, more than the agency had received about those devices in the previous four years combined.

The vast majority of filings appear to reflect patients who have had an all-metal hip removed, or will soon undergo such a procedure because a device failed after only a few years; typically, replacement hips last 15 years or more.

The mounting complaints confirm what many experts have feared — that all-metal replacement hips are on a trajectory to become the biggest and most costly medical implant problem since Medtronic recalled a widely used heart device component in 2007. About 7,700 complaints have been filed in connection with that recall.

Though immediate problems with the hip implants are not life-threatening, some patients have suffered crippling injuries caused by tiny particles of cobalt and chromium that the metal devices shed as they wear.

Hip replacement is one of the most common procedures in the United States and, until a recent sharp decline, all-metal implants — one in which both the artificial ball and cup are made of metal — accounted for nearly one-third of the estimated 250,000 replacements performed each year. According to one estimate, some 500,000 patients have received an all-metal replacement hip.

One of the most problematic devices, the A.S.R., or Articular Surface Replacement, was recalled last year by Johnson & Johnson and accounted for 75 percent of the complaints reviewed by The Times. A precise count of failed implants reported to the F.D.A. is hard to come by because of the agency’s overlapping reporting system, though The Times sought to eliminate duplicate reports about the same incident. Some complaints came from outside the United States.

Under F.D.A. rules, many all-metal devices were sold without testing in patients or without a requirement that producers track their performance. But in an unusual intervention, the F.D.A. in May ordered producers to study how frequently the devices were failing and to examine the threat to patients. Now, researchers say, producers face substantial hurdles in recruiting the hundreds of patients needed to conduct sound studies because of the lack of patient registries.
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