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.
Tim Shaffer for The New York Times
Ann Morrison experienced pain, rashes and inflammation soon after receiving all-metal replacements for each of her hips.
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.
The New York Times
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.
“They are grasping at how they are going to get this information,” said Dr. Robert S. Namba, an orthopedic surgeon with Kaiser Permanente.
In addition, researchers are struggling to understand the tissue damage caused by the metallic debris. While some patients experience pain, other patients with the same damage have no pain, complicating decisions about whether to remove devices.
As problems and questions grow, most surgeons are abandoning the all-metal hips, saying they are unwilling to expose new patients to potential dangers when safer alternatives — mainly replacements that combine metal and plastic components — are available. Some researchers also fear that many all-metal hips suffer from a generic flaw. Current use of all metal devices has plummeted to about 5 percent of the market, though a few of the models are performing relatively well in select patients.
“It is like playing Russian roulette,” said Dr. Geoffrey H. Westrich, an orthopedic surgeon at the Hospital for Special Surgery in New York, who has stopped using all-metal implants.
Dr. William Maisel, the chief scientist of the F.D.A. division that oversees medical devices, said he believed that producers would mount rigorous studies and find answers. But he acknowledged that it could take several years.
“There is not an existing infrastructure for studying this kind of information,” Dr. Maisel said.
For many patients, it is too late. In 2008, Ann Morrison, a physical therapist from Newark, Del., received all-metal replacements for both of her hips. But Ms. Morrison, 50, soon experienced pain, rashes and inflammation.
Last year, the devices were replaced, but by then, she said, debris-caused tissue damage was so extensive that she now needs a brace to walk and still cannot work. She called the F.D.A.’s order for medical studies a “joke.”
“We will be the little crash test dummies here until they figure out the health ramifications for us down the road,” said Ms. Morrison, who has sued the DePuy division of Johnson & Johnson, which made her implants.
To conduct its analysis, The Times reviewed complaints filed with the F.D.A. from 2007 through this June for several implants, including the A.S.R. and the Durom cup, a component sold by Zimmer Holdings.
Typically, the number of complaints filed with the F.D.A. about a product understates a problem because while companies must file reports, doctors and patients do not have to. The filing volume for the A.S.R. and the Durom cup probably reflects a surge of lawsuits filed against their makers.
The Times review found some 7,500 complaints about the A.S.R., nearly 5,000 of them coming since January. In the case of the Durom cup, about 1,600 complaints were filed with the regulator from 2007 to this June.
Because complaints to the F.D.A. are not uniform, it is impossible to say how many adverse reports about all-metal hips have been submitted. For example, the Times analysis found some 200 complaints about an all-metal version of another DePuy device called the Pinnacle as well as 400 additional complaints that noted metal-related problems in Pinnacle patients. But the Pinnacle is sold in several versions, so it was not clear how many of the metal-related complaints were linked to the all-metal device.
A spokesman for Zimmer Holdings said the Times review was “in the ballpark” of the company’s assessment of the drug administration’s filings. A DePuy spokeswoman declined to disclose the number of A.S.R. complaints that the company forwarded to the F.D.A. She maintained that the Pinnacle was performing well.
DePuy, Zimmer and another producer of metal hips, Wright Medical, declined to discuss the study proposals they had submitted to the F.D.A. to comply with its May order. A fourth company, Biomet, said it had proposed mounting a study of 400 patients who received its devices that would draw in part on studies already under way. The F.D.A. declined to release producers’ proposals, saying that they contained “confidential commercial information.” The agency has until November to decide on the plans’ adequacy.
In an effort to recruit patients, companies have recently contacted, researchers said, health systems like Kaiser Permanente and hospitals that operate their own implant registries.
Meanwhile, researchers say it may be a year before standard protocols are formulated that may be central to the future studies, like a uniform procedure to measure metallic ions in a patient’s blood or how to calibrate diagnostic equipment to best detect tissue damage.
© 2011nytimes.com
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