As of this past September, about 3,500 DePuy ASR hips had been implanted in patients in Ireland. DePuy Orthopaedics, the maker of the metal-on-metal hip devices, is an orthopedic unit under Johnson & Johnson.
The Irish Medicines Board (IMB) has since been collaborating with Great Britain’s Health and Safety Executive (HSE), as well as with Irish orthopedic surgeons on recommendations for how to conduct individual patient follow-up, according to Irish Medical Times. As of July 2012, the HSE indicated that about 96 percent of patients implanted with the metal-on-metal devices had attended review, of follow-up, appointments and more than 350 had undergone revision surgery to have the devices removed. An additional 166 patients have been scheduled for revision surgery.
Since, all patients have undergone follow-up appointments. Also, according to the Irish Medical Times, an independent review of the explanted, or removed, devices, is being conducted at the London Implant Retrieval Centre in the United Kingdom.
Meanwhile, recent research reveals that some hip implants on the United States market received clearance with minimal or no proof of efficacy or safety.
All-metal hip device implants, including the DePuy ASRs, were marketed to last for at least two decades and to provide increased range of motion, when compared to traditional hip replacement devices made with plastic or ceramic components. The metal-on-metal hips, instead, have been associated with high and premature failure rates, increased blood metal ion levels and metal poisoning, and mounting litigation. Injury reports also allege dislocation; pain; fracture; difficulty ambulating, rising, standing, and balancing; noise emanating from the joint; and pseudotumors.
Mechanical wear of hip device implants is seen in all types of the devices over time. The femoral head and acetabular cup component surfaces rotate against each other with normal wear and tear, such as walking. With metal-on-metal systems, tiny shards of metal may be released leading to the accumulation of cobalt and chromium metal ions within the area surrounding the implant, according to the Irish Medical Times.
Johnson & Johnson faces about 12,000 lawsuits that have been filed in federal and state courts in Ohio, California, and New Jersey, according to a recent Bloomberg.com report. The device maker also recently reached a $2.47 billion settlement to resolve thousands of these pending lawsuits. It is believed that the amount may go as high as $4 billion.
We have long pointed out that not all medical devices are tested for safety before they are released to market, a long-discussed issue that has given rise to increased controversy, especially concerning metal-on-metal hips. In the United States, device makers may seek U.S. Food and Drug Administration (FDA) clearance through a 510(k) application should a device be substantially similar to a device that has already been approved. Under this clearance route, device makers are only required to file paperwork with the FDA and pay a $4,000 fee, according to Newsmax Health. Only after a device is on the market and has been tied to increased injury reports—so-called “post-market surveillance”—does the agency become involved.