Metal-on-Metal Hip Implant Defects
Metal-on-Metal Hip Implants – DePuy and Stryker Hip Recalls
Several hip implants manufacturers are involved in lawsuits because of complications suffered by people who received faulty hips. In these lawsuits, those injured claim that the companies made defective products and failed to warn the public about the risks. DePuy, a Johnson & Johnson company, faces nearly 12,000 lawsuits filed by people who received the ASR hip implant and another 3,000 from recipients of its Pinnacle hip. DePuy will pay $2.5 billion to settle 7,500 of the ASR claims. The all-metal hips were supposed to last longer than other implants on the market. Instead, they failed prematurely in thousands of people.
Hips manufactured by Stryker have also been recalled. Two of Stryker’s most recent hips – the Rejuvenate and ABG II Modular-Neck Hip Stem systems, both released in 2009 – have been a source of problems. Both of these models were recalled in July 2012 after patients complained of various problems. Unlike typical hip implant systems, which include a one-piece neck and stem called a monoblock design, Stryker’s Rejuvenate and ABG II 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.
Post-market data revealed evidence of corrosion and fretting after the hips were implanted, and Stryker recalled both types of hips. The recall came too late for some patients and unfortunately 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.
Recent recalls of hip implants have focused on the metal-on-metal ball-and-socket components, which can release metallic debris into the body through 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. But, 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. This is what causes the same complications as the 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 hips because of the tendency for metal components to rub against one another, depositing small shards of metal into a patient’s tissues, bones or bloodstream.
If you or a loved one have had a Rejuvenate or ABG II hip stem component implanted, contact the CQH Firm at 1-(844) 677-4276 for a free consultation.