Metal-on-metal hip implants have traditionally been cleared under the FDA’s 510(K) premarket notification pathway, which requires that a manufacturer demonstrate that the device is similar to another product already on the market. It does not require companies to prove a device’s safety or effectiveness.
Johnson & Johnson’s DePuy Orthopaedics business unit introduced its metal-on-metal hip implants in 2003 after receiving 510(K) clearance from the FDA.
Seven years later, DePuy recalled the devices, which had been implanted in 93,000 patients worldwide, leading to hundreds of lawsuits and an estimated $184 million in related recall costs for Johnson & Johnson.
Smith & Nephew recalled the metal liners last year for its metal-on-metal hip implant system. The DePuy and Smith & Nephew recalls were attributed to high rates of revision surgeries, according to the FDA.
“In seeking review of its products, DePuy Synthes Joint Reconstruction will continue to comply with all applicable FDA regulations,” a DePuy spokeswoman said in an e-mailed statement.
“These reports, as well as recent recalls of devices from the U.S. market, have indicated that preclinical testing currently used to support marketing clearance of these devices has not been sufficient to mitigate the risks associated with these devices and identify potential clinically relevant failure modes,” the FDA said in the proposed order.
The agency had previously requested post-market studies of metal-on-metal implants from 21 device manufacturers and held a panel discussion last June to gather additional information.
However, the recalls of metal-on-metal hip implants have led to broader questions about why implantable devices have been approved under the expedited 510(K) pathway rather than the more rigorous premarket approval process, which requires clinical data.
Ongoing concerns prompted Congress members to include a provision in last year’s user-fee agreement legislation that allows the FDA to reclassify devices by order rather than by regulation.
This month, the authors of a perspective article published in the New England Journal of Medicine noted that a clinical trial might have identified the high revision rate of the DePuy ASR XL Acetabular Cup System.
“As thousands of Americans are painfully learning, there are unknown risks with devices that enter the market without clinical data showing safety and effectiveness, and implanted body parts cannot be recalled as easily as defective auto parts,” the perspective’s authors wrote.
The board of the American Academy of Orthopaedic Surgeons last month approved a consensus statement it developed with the American Academy of Hip and Knee Surgeons and the Hip Society that provides proposed courses of action for physicians caring for patients who received the metal-on-metal hip implants.
“We do support the FDA and their process and explorations of the issues involved in the devices,” said Dr. Josh Jacobs, AAOS vice president.
Metal released by the implants can cause damage to a patient’s bone or soft tissue, which can then lead to pain, implant loosening, device failure, the need for revision surgery and elevated metal ion levels. Managing the care of patients who have received metal-on-metal implants has been a challenge for orthopedic surgeons, according to Jacobs.
“We have to take into consideration a number of factors,” such as when to closely monitor a patient; use blood tests or imaging; or plan for revision surgery, he said.
The FDA also issued information today that recommends how physicians, providers and patients should assess metal-on-metal hip implants.