DePuy ASR Hip Implant was Untested

Could the controversial recalled <"">DePuy hip replacement devices that have been making headlines for months for high failure rates have been rushed through clinical safety trials to receive U.S. Food and Drug Administration (FDA) approval? This is just one of many issues being brought up in the growing number of DePuy hip implants lawsuits being filed against DePuy Orthopaedics, a unit of drug giant Johnson & Johnson.

A metal-on-metal device made of chromium and cobalt, the DePuy ASR Hip Implant System consists of a cup implanted into the hip with a ball joint that connects to the leg. In August, DePuy Orthopaedics issued a recall for the ASR XL Acetabular Hip Replacement System after data from the National Joint Registry of England and Wales showed that 1 out of 8 patients (12%-13%) who had received the devices had to undergo revision surgery within five years of receiving the surgery. Recent reports indicate that these figures could be lower than emerging reports.

Patient complaints include grinding, slipping, and popping sensations and related noises; pain and difficulty walking, that in one case reported by HamptonRoads, nearly drove a patient to a wheelchair; revision surgery to remove the defective device and implant the patient with a different device; and, in some cases, double revision surgeries for patients who underwent two hip replacements with the faulty devices.

Meanwhile, said HamptonRoads, hip replacement surgeries are up, increasing by about 30 percent in the decade from 1996 to 2006; with Baby Boomers aging, the surgeries are expected to increase by about 175 percent by 2030.

The recalled DePuy devices were approved via a 510(K) approval process in which eligibility requires manufacturers only prove that the new product is equivalent to one already on the market; human tests are not required. In this case, DePuy’s artificial hip devices, which received approval in 2005, were similar, noted HamptonRoads, to other devices that used metal or ceramic for the ball and plastic for the cup; the ASR device used metal for the both with the intention that the new device would last longer.

Instead, the device has experienced an unprecedented failure rate with many of the complications linked to wearing of the metal components, which can allow cobalt and chromium shavings to make their way into patients’ bloodstreams. This can cause a reaction known as metallosis, which can cause tissue breakdown; bone loss; and cobalt poisoning, a disorder that, if untreated, can put patients at risk of tinnitus (ringing in the ears), vertigo, deafness, blindness, optic nerve atrophy, convulsions, headaches, peripheral neuropathy, cardiomyopathy, and hypothyroidism.

Sadly, these dangerous side effects are being experienced by patients unaware that their device was pushed through an approval process that never required traditional clinical trials, which could have unearthed the device’s myriad adverse reactions.

Meanwhile, we recently wrote that a new study found that the majority of high-risk medical device recalls over the past five years involved products subject to the FDA streamlined 510(K) approval process. The study appears on The Archives of Internal Medicine website. The authors said the FDA should require clinical trials in humans for more devices rather than letting them through the abbreviated review process. According to the study, of 113 devices recalled 2005-2009, most—about 80 percent—received approval under the 510(k) process. Although hip devices were not part of this study, pointed out HamptonRoads, because the study reviewed devices that could prove life-threatening if defective, its research revealed that 158 hip devices were recalled in the same time frame. In February, the FDA announced that it is taking another look at metal-on-metal devices, said HamptonRoads.

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