All recipients of a metal-on-metal hip implant could be subject to adverse tissue reactions, corrosion, pseudo-tumors, loosening or failure of the implant and metallosis. Stryker issued a voluntary recall of their Rejuvenate and ABGII hip implants on July 6, 2012 after post-market reports indicated a risk of corrosion and fretting at the neck juncture. Just last February, the British Medical Journal warned the public about potentially elevated levels of metallic ions released by hip implants which utilize metal components. A study published in The Lancet noted that the metal-on-metal hip implants showed a significantly higher failure rate than their ceramic and polyethylene counterparts and in 2011 alone, over 12,000 complaints came into the FDA regarding metal-on-metal hip implants.
The designs of the Stryker Rejuvenate and ABGII are a bit different from other all-metal hip implants as they are constructed of a ceramic ball rather than a metal one. On the surface it would seem that this change would eliminate the risk of metallosis since there would be no metal ion release from friction between the ball and acetabular cup. This turned out not to be the case as an urgent field safety notice issued by Stryker to hospitals and physicians in April—prior to the recall in July—noted a risk of metal ion release from corrosion at the metal neck juncture. Later it was also found that the metal trunnions located on either end of the neck component could trap body fluids beneath them, also leading to corrosion. Although this corrosion is on a smaller scale due to the smaller surface area, it can nonetheless lead to metallosis just as with the metal ion shear in the all-metal hip implants.
Any level of cobalt and chromium in the body can lead to serious health problems, particularly in those who are especially sensitive to the metals. Even those with a relatively high tolerance to the metals could find themselves falling very ill once the metals reach an alarming level. Should the metal ions find their way into the tissues surrounding the hip implant, inflammation, pain, tissue loss or tissue death and bone loss could all occur. In the bloodstream cobalt and chromium can wreak havoc in a number of ways. Cardiovascular problems are a risk when the metals enter the bloodstream as are renal, thyroid and neurological issues. Vision and hearing impairment can occur from exposure to cobalt and chromium as well as fatigue, anxiety, depression, loss of memory, chronic headaches, vertigo, skin disorders, gastrointestinal problems, pseudo-tumors and even disruption of DNA.
Revision surgery is generally the only choice once metallosis has occurred, the implant has failed, or the patient is in constant pain. Revision surgery for the Rejuvenate or ABGII is, unfortunately, much more serious than for other all-metal hip implants. The stem of these two Stryker models is implanted much more deeply into the femur than other hip implants; removal involves actually digging the implant out from the surrounding bone which brings a substantial risk of the femur shattering or fracturing. Any person with a Stryker Rejuvenate or ABGII—whether they have yet experienced adverse symptoms or not—should take special care to undergo regular medical evaluations including blood work to test the levels of cobalt and chromium as well as other doctor-recommended tests which could include x-rays, bone scans and MRIs. Metallosis is an extremely serious health problem and a very real risk for those with the Stryker Rejuvenate or ABGII hip implant.