RX for Change: Excuse Me, Is that a Metal-on-Metal Device You’re Wearing?

Article taken from January/February Newsletter 2012

Hip replacement, a surgical procedure where the hip joint is replaced by a prosthetic device, is usually done to relieve severe pain and mobility problems in a natural joint damaged by arthritis or trauma. Usually, both the “ball” (i.e., femoral head) and “socket” (i.e., acetabulum) are replaced, with excellent results. Unsuccessful hip replacement, however, can result in more pain and an inability to walk at all. And, devices with a metal ball and socket (metal-on-metal, or MoM) can cause other problems, some of which are extremely dangerous. Astonishingly, the Food and Drug Administration (FDA) allows some types of joint replacement devices to be used without any clinical studies on safety or efficacy.

The earliest recorded hip replacement procedure, performed in Germany in 1891, replaced the femoral head with carved ivory. Thankfully, many elephants and walruses have been spared as surgeons and engineers pioneered prostheses made of metal, plastics, and ceramic components!

Today, there are hundreds of designs of artificial joints. In some countries — including Britain, Sweden, Norway, Denmark, South Africa, and Australia — detailed data on joint replacement patients is entered into national registries. Registries help curtail the widespread use of dangerous products by quickly identifying devices with high failure rates and other problems, and allowing physicians and patients to be alerted when problems are found.

Each year, over 600,000 Americans have hip and knee replacement surgeries; hospital costs alone from the procedures will exceed  $65 billion in 2015. Despite leading the world in joint replacement procedure frequency, however, the U.S. has no comprehensive joint replacement registry, nor is one planned by any government agency, the American Academy of Orthopedic Surgeons, or the highly profitable joint replacement manufacturing industry. As a result, Americans’ health is jeopardized by unsafe and ineffective devices.

A recent case illustrates the devastating effect of unfettered industry combined with lax Federal regulation. DePuy Orthopaedics, a division of Johnson & Johnson, is the world’s largest hip replacement device manufacturer. DePuy promoted its Articular Surface Replacement (ASR) MoM device as a “breakthrough design” that would last 15 years (like comparable devices) or longer. In 2005, the FDA cleared DePuy to market the ASR in the U.S. without conducting any human safety trials. Like many medical devices, the ASR was approved as “substantially equivalent.” This means that, although it had a new design and untested combination of materials, the FDA considered the ASR to be enough like existing devices to be put directly into humans without any specific safety research or requirement for DePuy to monitor its actual performance or safety.

By 2008, the FDA had received about 400 complaints from patients. Orthopedic surgeons also began seeing unusual symptoms and early failures with the ASR. When they alerted DePuy, the surgeons were told the ASR was fine, and faulty surgical techniques were at fault. At the same time, savvy nations with joint registries began to note an epidemic of ASR failures.

Other problems soon became evident. When surgeons began to replace the ASRs, they found tiny metal fragments had sloughed off the device and inflamed tissues; some patients had permanent damage to tissues adjoining the ASR. Another horrifying complication was heavy metal poisoning caused by cobalt and chromium released by the ASR and absorbed into the patient’s blood. Cobalt poisoning can cause neurological symptoms (like tremors, cognitive decline, and hearing loss), cardiac arrhythmias (abnormal heart rhythms), and hormonal problems. Some patients without any hip-related symptoms developed severe illnesses from toxic cobalt levels.

Despite accumulating evidence on how shoddy the device was, DePuy promoted the ASR and eventually sold about 93,000 worldwide (about 30,000 in the U.S.). In early 2010, DePuy announced it would phase out the ASR because of declining sales. In August, 2010, DePuy voluntarily recalled the ASR and said it would pay for surgery to replace it, if needed. Replacing dangerous and ineffective ASRs will help some patients, but others already have such extensive and permanent damage that surgery won’t help. Others may have no hip problems, but may develop cobalt poisoning, which, if unrecognized, can cause permanent harm.

Have the ASR debacle and problems with other joint replacement devices spurred the U.S. to invest in a national joint registry? Not really. There’s been a tiny start, but a lot more huffing and puffing about how to maintain privacy of patient information, if the registry could report problems to the FDA, and concerns about cost. Give us a break! This is a multibillion-dollar industry with at least 50% of the bill footed by U.S. taxpayers through Medicare and Medicaid. What about patients’ lives and well-being?

Actually, one U.S. health insurer can show us the way. In 2001, Kaiser Permanente started its own joint replacement registry, which has improved quality and saved costs. Kaiser’s surgeons use registry data to guide their techniques and select which joint implant to use. When another hip implant was recalled (before the ASR), Kaiser was able to notify its patients promptly.

Our recommendation: If you, or anyone you know, had hip replacement from 2005-10, learn the device’s make and model. If it is an ASR or other MoM device, take this article to your primary care doctor AND your orthopedic surgeon, and get both an in-depth evaluation of the device and blood tests to assess cobalt and chromium levels. We can all contact our Congressional representatives to demand the U.S. catch up with other nations and Kaiser by creating a state-of-the-art, national joint replacement registry.

 

Charlea T. Massion, MD, is a family physician and co-founder of the American College of Women’s Health Physicians; she teaches at Stanford University School of Medicine’s Center for Education in Family Medicine. Adriane Fugh-Berman, MD, is an associate professor in the Georgetown University Medical Center, a former chair of the NWHN, and director of Pharmedout, which educates prescribers about pharmaceutical marketing  techniques.


 

Resources:

Australia Orthopedic Association (AOA), AOA National Joint Replacement Registry: Supplementary Reports, 2011: Investigations of Prostheses with Higher than Anticipated Rates of Revision, University of Adelaide SA, October 2011. Available at http://www.dmac.adelaide.edu.au/aoanjrr/publications.jsp

Food and Drug Administration (FDA), “Information for Patients Who Have Metal-on-Metal Hip Implants”, Silver Spring, MD: FDA, Updated 2/10/11. Available athttp://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/ImplantsandProsthetics/MetalonMetalHipImplants/ucm241766.htm#q4

Meier B, “Remedy Is Elusive as Metallic Hips Fail at a Fast Rate”, New York Times, September 30, 2011, page A1. Available at: http://www.nytimes.com/2011/10/01/health/01hip.html?pagewanted=all

Meier B, “Metal Hips Failing Fast”, New York Times, September 15, 2011, page B1.Available at: http://www.nytimes.com/2011/09/16/health/16hip.html

Meier B, “Implant Loophole”, New York Times, December 16, 2010, page B1.  Available at: http://www.nytimes.com/2010/12/17/business/17hip.html?scp=1&sq=hip%20j&J=&st=cse&pagewanted=1

Paxton E, “The Kaiser Permanente National Total Joint Replacement Registry”, The Permanente Journal2008; 12(3): 12-16.

U.K. Medicines and Healthcare Products Registration Agency (MHRA), “Medical Device Alert: All metal-on-metal (MoM) hip replacements (MDA/2010/033)”, London: MHRA, April 22, 2010. Available online athttp://www.mhra.gov.uk/Publications/Safetywarnings/MedicalDeviceAlerts/CON079157