Johnson & Johnson decided to phase out one of the hip implants made by its subsidiary DePuy Orthopaedics and sell off its inventory shortly after receiving an inquiry from the Food and Drug Administration (FDA) that questioned the device’s safety and efficacy. The federal agency was asking the drug and medical device manufacturer for safety data on its metal-on-metal ASR XL Acetabulator hip replacement and hip resurfacing systems, and informed the company that blood tests in patients who had received the implants showed “high levels of metal ions.”
The latest news adds more concern that DePuy and Johnson & Johnson may have been aware that the company’s all-metal hip device was defective but continued to market it. The company did not officially recall the hip implant until August 2010. An estimated 93,000 people worldwide are affected by the recall.
DePuy’s artificial hip recall was in large part the catalyst that brought into question the FDA’s approval process for so-called “moderate risk” devices. For several years, the agency has allowed medical devices in this category to be approved for use without clinical tests if similar devices were already on the market.
While similar in design, traditional implants are made with ceramic or plastic parts. The DePuy implant was made with all-metal parts, a design that was meant to make the device more durable over time. However, it appears to be anything but. As the metal parts of the implant moved together, tiny bits of metal were found to flake off into the joint space. This may lead to inflammation and muscle damage in the tissue surrounding the implant, not only leading to device failure, but also posing a risk of blood poisoning if it leeched into the bloodstream.
Under pressure, the FDA has proposed changes to its accelerated approval process for medical devices. Hundreds of lawsuits also have been filed against Johnson & Johnson and DePuy by patients who claim they were injured by the defective hip implants.
Source: NY Times