ATTENTION: Read about the recent Stryker Hip Settlement!
January 04, 2015 - Stryker and the FDA
Just as with the DePuy ASR, the Stryker Rejuvenate and ABGII gained FDA approval via the 510(k) approval process. The Rejuvenate gained FDA approval based on its substantial similarity to the Wright Profemur, which, as of this date, has had hundreds of adverse event reports submitted to the FDA regarding metallosis and metal toxicity. A 2008 report issued by the Australian National Joint Replacement Registry claimed the Wright ProFemur had a revision rate of several times that of comparable hips. A review of the FDA database revealed that Stryker had been experiencing troubles with the Rejuvenate and ABGII for some time prior to the urgent field safety notification and the subsequent recall. As early as July of 2010, one surgeon noted that one of his patients suffered significant fretting at the stem/neck juncture as well as obvious tissue degradation from a Rejuvenate implant.
Later, in 2010, another surgeon noted evidence of corrosion at the modular junction, and in January of 2011 yet another surgeon noted corrosion resembling “black rust” on a patient’s Rejuvenate implant. During 2011, another six notifications came in from surgeons which stated they had seen patients with black material on the modular neck of their Rejuvenate or ABGII, massive metallosis, the presence of a milky fluid in the soft tissues and that all the patients were in extreme pain. In 2010 the FDA received at least 60 adverse events involving a Rejuvenate or ABGII, and by the end of 2011, that number had risen to 130.
During the first half of 2012—prior to the recall, the number of adverse event reports submitted to the FDA had climbed to 300. Failure of the Rejuvenate and ABGII in other countries was on the rise as well: the Australian Registry calculated a failure rate of 8.1% in the first year following implantation of an ABGII modular hip stem and noted that of 164 ABGII devices implanted in Australia, ten had already failed completely.17 Despite the growing evidence that the Rejuvenate and ABGII had potentially serious problems, Stryker continued to sell both models.
The Stryker Recall
A month after Stryker issued the Urgent Field Safety Notification, Health Canada announced that Stryker would recall the Rejuvenate hip implant being sold in Canada. On July 6, 2012, Stryker finally made the decision to recall all Rejuvenate and ABGII devices sold and implanted in the United States due to the risks associated with fretting and corrosion at the modular neck junction which could result in adverse local tissue reactions and a higher-than-normal rate of hip failure.
While Stryker has declined to offer a failure rate for the Rejuvenate and ABGII, some doctors have placed that number as high as 40, 50, 60 and even 70%.18 Some speculate that the recalled Stryker Rejuvenate and ABGII could turn out to be an even bigger disaster than that of the DePuy ASR—only time will tell. In the meantime, all those harmed by one of these recalled hip devices must determine how to best move forward with a future which has been harmed by a device they believed to be safe.
The Differences Between the Rejuvenate and the ABGII
The Rejuvenate and the ABGII are alike in many ways; both devices implement a ceramic component as an alternative to the “true” metal-on-metal hip implants. Both Stryker models were marketed specifically toward the younger, more active patient, and both models have the capabilities to be custom-fitted to the individual implant recipient. Both models include a cobalt and chromium neck piece, however the proportions of the metals are somewhat different. The stems of both the ABGII and the Rejuvenate are manufactured from Stryker’s proprietary titanium alloy blend which was supposed to resist fretting and corrosion, however the stem of the Rejuvenate is longer than that of the ABGII.
This is a distinction that can have serious implications should the necessity of a hip revision arise. The longer Rejuvenate stem is implanted much more deeply into the femur, making it more difficult to remove. The hydroxyapatite porous coating of the Rejuvenate is very rough and deep, allowing the bone to grow more deeply and solidly into the device, while the coating of the ABGII is much smoother and shallower, making it easier to remove from the surface of the bone during revision surgery.