How are the Stryker ABGII and the Rejuvenate Different?

The Stryker Rejuvenate hip implant device received FDA approval in June of 2008, while the ABGII hip implant device received FDA approval in November, 2009. Just a few short years later the FDA began receiving adverse reports regarding both hip implants. In April, 2012 Stryker issued an Urgent Field Safety Notice to doctors and hospitals stating the risks of fretting and corrosion, leading to metal ion debris. These microscopic cobalt and chromium ions can enter the bloodstream or lodge in nearby hip tissues, creating a host of adverse health issues.

When the shards burrow into the hip tissues, inflammation, chronic pain and the destruction and death of tissue and bone can occur. Should the cobalt and chromium enter the bloodstream, metal toxicity can occur, resulting in cardiovascular, neurological, renal, thyroid and gastrointestinal issues, loss of vision and hearing, the development of pseudo-tumors, DNA disruption, chromosomal abnormalities, chronic headaches, vertigo, depression, anxiety, and irritability.

Following the field safety notification, Stryker issued a recall of both the ABGII and the Rejuvenate in July, 2012. Between the time the devices received FDA approval and the time of the recall, over 20,000 implants were sold; it is believed most of those were implanted into patients. While Stryker claims their failure rate to be somewhere around 12%, independent studies have placed the risk of failure much higher—some as high as 48-50%. This means that while the lawsuits presently number in the low hundreds, it is likely there will be many more filed in the next year.

The Similarities Between the Rejuvenate and the ABGII

The basic design of the ABGI and Rejuvenate vary considerably from the design of other metal-on-metal hip implant devices. The primary differences revolve around the fact that the Rejuvenate and the ABGII implement a ceramic ball rather than a cobalt and chromium ball as many other all-metal devices. In fact, it was widely believed that Stryker’s Rejuvenate and ABGII would not cause the same adverse health risks of the other metal implants due to the ceramic component included in the design.

The design of these two Stryker devices kept a metal neck and stem piece, and offered a wide variety of sizes and lengths of components in order to allow the surgeon to piece together a hip implant which would most closely align with the individual’s body type and level of activity. Unfortunately, the claims of Stryker regarding the Rejuvenate and ABGII did not pan out as expected. The metal joints between metal parts bring a significant risk of fretting and corrosion due to the movement in the joints.  

Differences in the Stryker ABGII and the Rejuvenate

Perhaps the primary difference between the two recalled Stryker hip implants is the hydroxyapatite porous coating; while the coating of the Rejuvenate is very rough and deep, encouraging the bone to grow deeply into the coating, the coating of the ABGII is much shallower and smoother. During revision surgery, the coating of the ABGII makes it considerably easier to remove the device and implant another. Both the ABGII and the Rejuvenate stems are manufactured using a propriety blend of titanium, molybdenum, zirconium and iron. While Stryker claimed this innovative mixture would resist fretting and corrosion, post-market data did not support that claim.

The neck piece of both devices is constructed from cobalt and chromium, however the proportions of the metals are somewhat different. The stem of the Rejuvenate is longer than the stem of the ABGII, again, making the Rejuvenate more difficult to remove during revision surgery as it is implanted more deeply into the femur. If you are the recipient of either a Stryker ABGII or Rejuvenate it is important that you speak with your physician regarding your levels of cobalt and chromium.