The nightmare of metal-on-metal hip replacement systems continues. Once believed to be a safe, durable and long-term alternative to ceramic and plastic hip implants, the metal-on-metal devices have seemed to bring nothing but trouble and concern for patients who have received them. There are now multiple voluntary and FDA-initiated recalls that affect tens of thousands of patients who went through hip replacement surgery only to find that their problems continue—or worsen.
Perhaps most well-known of the recalls is the 2010 massive global recall of the DePuy ASR hip implant system. The recall was based on a UK study that showed an unacceptably high rate of revision surgeries for recipients of the system. In addition, all patients face an increased risk of cobaltism or metallosis, a condition that develops when two metal components of the hip replacement system rub against each other, releasing small metal particles into the blood stream.
But these problems are not unique to just DePuy. They are common to all metal-on-metal systems and other manufacturers are also facing massive recalls. In 2008, the Zimmer Durom Acetabular Component was recalled, citing similar concerns. And more recently at the beginning of June, the manufacturer Smith & Nephew voluntarily recalled all of its metal liners for its hip implant system. And yet another device, the Stryker Rejuvenate Hip Implant, is coming under close scrutiny for a number of adverse events that indicate serious safety and effectiveness concerns related to the device.
As these recalls and adverse events pile up, it’s impossible not to wonder how the FDA got this so wrong. But part of the problem seems to be related to a fast-track approval system that these devices went through, meaning that there were no clinical trials before thousands of patients started receiving these devices. Just recently the FDA finally hosted an expert panel to discuss the safety of metal-on-metal systems. The outcome of that panel session is not yet known, but hopefully it results in a significant step forward to ensure higher standards for hip implant systems.