Understandably, recipients of the Stryker Rejuvenate or ABGII hip implant device are concerned about the release of chromium and cobalt following corrosion of the implant. Those who watched the movie “Erin Brockovich” may recall that hexavalent chromium was found in the drinking water of a small town in California turning out to be an extremely toxic substance, causing cancer and other serious diseases. There are two types of chromium--one type of chromium known as trivalent chromium occurs naturally in the environment and is an essential nutrient for normal glucose, protein and fat metabolism. Most of us are exposed to trivalent chromium simply from eating food, drinking water and inhaling air. While this type of chromium sounds relatively harmless, when the body is continuously exposed to the metal ions of trivalent chromium it can be harmful to the body as well.
Which Chromium is in My Stryker Rejuvenate or ABGII Hip Implant?
Unfortunately, there is an abundance of conflicting studies regarding whether the chromium found in hip implants is hexavalent or trivalent. In 1990, the World Health Organization “listed hexavalent chromium as a proved carcinogen; trivalent chromium a potential carcinogen and cobalt ions a probable carcinogen.” Following the failure of thousands of metal hip implants across the globe, the London Implant Retrieval Centre confirmed the metal ion being released from hip implants was trivalent chromium. Contrarily, a study presented at the Society of Toxicology’s 52nd annual meeting in San Antonio, TX on March 12, 2013, stated “To date, no studies have attempted to analytically distinguish between non-toxic trivalent Chromium and potentially harmful hexavalent Chromium in these patients.” The study noted that while hexavalent chromium is known to accumulate primarily in the red blood cells, trivalent chromium remains largely confined to the serum compartment of the blood.
Testing for Chromium and Cobalt
While hexavalent chromium causes cancer and generally is more damaging to the body, higher levels of trivalent chromium exposure can cause DNA mutations, impair liver function, cause hypersensitivity at the implant site and reproductive issues. Other research indicates hexavalent chromium ions are released from metal hip implants, then that hexavalent chromium degrades in the body into trivalent chromium. Approximately 18-30% of metal hip implants are comprised of chromium, depending on the specific implant. Manufacturers generally will not state how much of their implant is composed of cobalt and chromium. Tests known as isotope/metal speciation are most commonly used to determine levels of hexavalent chromium.
Patients with a Stryker Rejuvenate or ABGII hip implant device should have regular blood testing done even if they feel well. Human bodies vary considerably in their tolerance for heavy metal exposure. While one person with relatively low levels may be extremely ill, another person with much higher levels of heavy metals may not yet be showing adverse symptoms. Both Stryker models were recalled in July, 2012, citing fretting and corrosion at the neck juncture leading to excess metal ion debris and possible hip failure. Stryker states the failure rate of the Rejuvenate and ABGII at approximately 12%; other studies have placed this number as high as 45-50%. Regular medical tests are essential for recipients of a Rejuvenate or ABGII in order to safeguard your health and your future.