Brent M Ardaugh et al - Comment

We wish to note the findings of our work concerning the 510(k) clearance process for metal-on-metal hip implants, as published in the January 10th issue of the New England Journal of Medicine (attached). We reviewed more than 1,200 pages of FDA documents to trace the predicate ancestry of the DePuy ASR XL, a metal-on-metal hip implant that was cleared without a clinical study and was implanted in approximately 30,000 Americans and 93,000 patients worldwide. Our investigation yielded two major findings: 1. The metal-on-metal design of the ASR XL was ultimately based on three preamendment devices that were discontinued long ago (and well before clearance of the ASR XL) because their risk of revision was so much higher than that of other hip prostheses. 2. The large metal-on-metal head size with sleeves component of the ASR XL was based in part on devices that were designed to articulate with the natural cartilage of the hip, not with a metal cup. This regulatory loophole that for decades has allowed “substantial equivalence” to serve as the legal standard for allowing these high-risk devices to reach Americans must be closed to avoid continued avoidable severe health effects for many Americans from the clearance of untested devices. The use of this standard for large-head metal-on-metal hip implants has proved catastrophic to the FDA, device companies, and most importantly patients. We support the proposed legal standard of “safe and effective” and emphasize the need for randomized controlled trials and data collection in postmarket surveillance, which would be best achieved through a nationwide registry. Sincerely, Brent M. Ardaugh, MPH Framingham Heart Study, Boston University School of Medicine Stephen E. Graves, MBBS Australian Orthopaedic Association National Joint Replacement Registry, Adelaide, SA, Australia Rita F. Redberg, MD Division of Cardiology, Department of Medicine, University of California, San Francisco