Saturday, February 16, 2013

Patients victims of untested medical devices

San Francisco Chronicle

For four years after she had her hip replaced in 2006, Sandy Rotenberg still had increasing pain, but her doctor kept telling her everything looked normal and prescribed more pain pills.

Then in October 2010, during a visit to get a cortisone shot, a different doctor looking at the El Cerrito woman's X-ray commented that her implant appeared to be one of the faulty all-metal devices made by Johnson & Johnson's DePuy unit that the company had recalled that August.

"I felt sick, terrified, but I also felt relieved," said Rotenberg, 53, who was born with a hip abnormality that caused early deterioration and arthritis. "I'd been hearing this attitude that was pretty paternalist and made me feel like this hysterical female. In some ways, it was just this huge relief to find out what was wrong."

Turns out Rotenberg was one of more than 93,000 patients worldwide to be implanted with DePuy's metal-on-metal replacement hip, known as the articular surface replacement.

Metal-on-metal implants, in which the cup and ball are made of metal, have been on the market for decades. DePuy's version, marketed to younger patients because it would last longer than conventional hip implants, came on the U.S. market in 2005. It not only failed in many patients but released tiny fragments of metal into the patients' bodies, causing tissue damage and other complications.

Untested devices

Considered one of the largest device failures in decades, the DePuy debacle highlights a little-known but stunning truth: These devices were cleared by the U.S. Food & Drug Administration without having to be tested in a single human being.

How does that happen? A loophole in FDA rules allow certain high-risk devices, including metal-on-metal hip implants, to bypass pre-market testing requirements if their manufacturers can convince the regulators that their device is "substantially equivalent" to a device already on the market.
A growing number of health experts, lawmakers and regulators are trying to close that gap.
"I don't think we should have devices on the market until we already know they are safe and effective," said Dr. Rita Redberg, a UCSF professor of medicine who co-authored an article in the New England Journal of Medicine last month calling for a change in FDA regulations. "Pre-market (clinical) trials would have caught the problem and 93,000 people would not have been implanted with a device that has since been recalled."

The rule that has allowed certain devices to skirt the process of undergoing potentially lengthy and expensive clinical trials dates to 1976, when the FDA started regulating medical devices, which include everything from heart defibrillators to infusion pumps to toothbrushes.

While the FDA requires implantable heart defibrillators and most other highest-risk devices to go through trials, it created a temporary approval process known as the 510(k) program as a stopgap measure to cover devices the agency had not yet classified for their level of risk.

Loophole never closed

This process would allow the FDA to clear these devices by deeming them similar enough to products already on the market. But the loophole was never closed and a number of devices, including metal-on-metal hip implants, have relied on the rule to get on the market.

The FDA has made several attempts over the years to classify metal-on-metal hips, but never completed the process. The agency restarted the effort on Jan. 18 under new rules passed last year designed to make device classification more streamlined.

For as long as the loophole exists, Dr. Kevin Bozic, chairman of the UCSF's department of orthopedic surgery, said better monitoring of devices after they are already on the market would help identify problems as they occur.

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