While the physical risks of all-metal hip implants have been extensively documented, scientists are only now learning more about the mental risks.
These devices contain high levels of cobalt. While this metal has not been studied as extensively as mercury, lead and some other heavy metals, researchers firmly believe that cobalt is as toxic to the brain as these other substances. The difficulty in studying the effects of all-metal hip implants on the brain has further hampered efforts, as the best way to conduct such research is to surgically remove the devices. However, doctors can use PET scans to look for early signs of brain injury.
Prominent Dr. Robert Bridges called cobalt the “new mercury” and urged device makers to use other materials.