The Stryker Corp. markets 57,000 products worldwide and generated more than $8 billion in annual sales in 2012. But, two of its hip implants, the Rejuvenate and ABG II Modular-Neck Hip Stems, can cause complications and were recalled in 2012.
Along with these two models, the company also recalled its Accolade TMZF Plus Hip Stem in 2009, 2011 and in 2013 for packaging and manufacturing errors. Like Rejuvenate and ABG II, Accolade is made of Stryker’s proprietary titanium alloy called TMZF. The stem has a PureFix HA coating, designed to help bone grow around the implant for a better fit.
Unlike typical hip implant systems, which include a one-piece neck and stem called a monoblock design, Stryker’s Rejuvenate, ABG II and Accolade systems include several neck and stem components. These modular, interchangeable systems were designed to give surgeons greater flexibility by offering them more anatomically correct implant components that could be custom-fitted to patients.
The ABG II system has eight right stems, eight left stems and 10 modular necks, which are supposed to offer greater stability and minimal bone stress. The Rejuvenate hip, with six stems and 16 necks, was marketed to younger patients who were promised longer-lasting devices that offered a better range of motion. The stems are manufactured using Stryker’s proprietary titanium alloy blend that mixes titanium, molybdenum, zirconium and iron. The company claimed that its patented blend resisted the effects of corrosion and fretting – small particles of metal flaking off the implant into the body. Stryker says this alloy “more closely resembles that of bone,” and it is also 20-percent stronger than other titanium alloys.
Unfortunately, post-market data revealed evidence of corrosion and fretting after the devices were implanted, and Stryker recalled the two systems. The recall came too late for some patients. The devices caused serious side effects, including loosening of the implant and the release of toxic metals into patients – complications that are leading to a number of lawsuits against Stryker.
Stryker Hip Implants and the FDA’s 510(k) Program
Stryker’s Rejuvenate Modular system was approved by the Food and Drug Administration (FDA) in June 2008. The ABG II system received FDA approval in November 2009. So, why did it take several years for the company to ascertain its products’ defects and potential dangers? Part of the answer can be found in the FDA’s approval process for medical devices.
Stryker submitted both systems through the FDA’s 510(k) Premarket Notification Process. Under the 510(k) program, a drug or medical device can be offered to the public without having to undergo clinical trials, if it can be shown that the product is substantially similar to a product that has already received FDA approval. In both cases, Stryker’s newer systems were approved because they were similar to other already sanctioned technologies.
So instead of testing these devices before they were marketed, the company was only required to conduct post-market surveillance. In other words, product safety did not have to be proven in advance. The obvious flaw in this system is that problems in 510(k) devices can only be found after they have been implanted in patients. Worse, the new Stryker devices were modeled on systems that already were suspected of having serious design problems themselves — problems that led to bone fractures and adverse tissue responses.
Stryker Hip Stem Complications
Recent recalls of hip implants have focused on the metal-on-metal ball-and-socket components, which can release metallic debris into the body during normal wear and tear. Stryker’s two modular-neck hip stem systems are not technically considered metal-on-metal devices, since they do not involve a metal ball rubbing against a metal socket.
However, because the Stryker necks are made of chromium and cobalt, and the stems are coated with titanium, they do have a metal-on-metal junction. And they can cause the same complications as other defective hip implants.
In April 2012, Stryker issued an “Urgent Safety Alert” to surgeons and hospital risk managers for the two hip replacement systems. The alert listed the potential hazards in these devices, including: “Excessive metal debris and/or ion generation,” caused by “fretting and/or corrosion at or about the modular neck junction,” which “may lead to increased metal ion generation in the surrounding joint space.”
For years, medical researchers have questioned the safety of metal-on-metal hip devices because of the tendency for metal components to rub against one another, depositing minute shards of metal into a patient’s tissues, bones or bloodstream.
|Contact between metal ions and surrounding cells can result in Adverse Local Tissue Reaction (ALTR), which can include:|
|Metallosis (metal toxicity from grinding metal components)|
|Necrosis (premature tissue death)|
|Osteolysis (bone dissolution)|
|Pain requiring revision surgery|
Stryker Hip Stem Recall
On July 6, 2012, after the FDA received more than 60 adverse event reports of metal toxicity requiring revision surgery, Stryker recalled its Rejuvenate and ABG II hip components in the United States and stopped all global production and sale of the devices.
The company advised patients fitted with modular-neck hip implant systems who experience persistent pain to undergo medical evaluations, including X-rays, MRIs and blood tests, to check for dangerously high metal ion levels. Medical professionals suggest that Adverse Local Tissue Reaction will generally require operative intervention and likely revision surgery with ceramic-on-metal modular junction replacement.
Since the stem components of a hip implant are driven deep into the patient’s femur, this type of revision surgery is considered particularly difficult for the physician and traumatic for the patient. In fact, there is a risk that the femur will fracture during revision surgery.
One patient, Dianne Pingel, had to have her femur reconstructed after multiple fractures developed in the thigh bone during revision surgery. Her surgeon told her that the metal ions from her hip implant caused the tissue and bone to die, weakening the bone and making it susceptible to constant dislocation and fracture.
Stryker Hip Lawsuits
Medical manufacturers are ethically and legally responsible for designing safe products. They are also obligated to warn consumers about products that are unsafe in sufficient time to prevent harm and/or device failure. When manufacturers neglect these responsibilities, victims can sue for compensation. Amounts received can cover the costs of past and future medical treatments, additional surgeries, and loss of wages or livelihood.
Lawsuits filed against Stryker accuse the company of negligence because it did not adequately test the Rejuvenate and ABG II before releasing them. They also claim the company failed to warn patients and doctors about the risk of side effects such as excessive ions in the blood and tissues surrounding the implant. Stryker has said that the recall and lawsuits could end up costing the company $1.3 billion. The first four Stryker lawsuits were settled in December 2013 for an undisclosed amount.
If you or a loved one have had a Rejuvenate or ABG II hip stem component implanted, contact Drugwatch. We make it our mission to help people injured by faulty devices like Stryker’s hip implants. Our Patient Advocates can help you with treatment options, answer questions about corrosion and fretting, and explain your legal options.