Recipients of all-metal hip implants or those hip implants which are partially constructed of metal such as the recalled Stryker Rejuvenate and ABG II, are likely painfully aware of the potential to develop symptoms of metal toxicity from the implant. When the metal parts of the implant suffer corrosion or rub against one another during periods of activity, microscopic metal ions travel through the body, wreaking havoc. When the particles land in the bloodstream, symptoms of metal toxicity can result. These symptoms include:
· Cardiovascular, neurological, renal, thyroid and gastrointestinal disorders
· Anxiety, depression or irritability
· Disruption of DNA
· The formation of pseudotumors
· Loss of vision or hearing
· Skin disorders
· Balance issues
· Chronic headaches
It is important that those with recalled implants or any hip device containing chromium and cobalt be vigilant about having regular blood testing done, even absent any overt symptoms. There are a number of tests currently used to detect levels of cobalt and chromium in the bloodstream. One of those tests is known as the inductively coupled plasma mass spectrometry (ICP-MS). This particular test can detect levels of metals as low as one part per trillion. The blood sample is ionized with inductively coupled plasma then separated by a mass spectrometer. Inductively coupled plasma is energized through heating the gas with an electrical coil. The ICP-MS test is faster as well as more precise and sensitive than older atomic absorption tests.
High-performance liquid chromatography is another test used to detect abnormal levels of cobalt and chromium in the bloodstream among patients who have metal hip implant devices in their body. Chromatography is described as a mass transfer process which relies on pumps to send a pressurized blood sample through a column filled with a granular material such as silica. The components of the blood are separated from one another then a digital microprocessor provides an analysis of the blood.
Field-flow fractionation (FFF) separates the blood sample through a fluid suspension or solution which is pumped through a long, narrow channel, perpendicular to the flow direction in order to achieve particle separation. The field in a field-flow fractional test is an asymmetrical flow through a gravitational, electrical, magnetic, centrifugal or thermal-gradient membrane. The presence of various species in a single sample can be identified through the resulting fractogram which indicates the presence of various species in the bloodstream according to their physical and chemical properties.
It’s important to remember that one type of chromium—trivalent chromium—is necessary for normal body functions. This type of chromium is often confused with hexavalent chromium which is extremely toxic to the human body and can lead to mutations which in turn lead to cancer if the body is unable to repair the damage. Isotope/metal speciation may be used to measure levels of hexavalent chromium, however lower detection limits are necessary in order to get a true picture of the levels in the human body. This same test shows promise in identifying cobalt poisoning in the body as well. Patients who have been implanted with the Stryker Rejuvenate or ABG II should see their physician regularly and report any symptoms such as pain, inflammation or any symptoms associated with metal poisoning.