Elevations of chromium and cobalt ions are directly and statistically
significantly associated with wear of metal on metal implants and the
ASR in particular. The more wear, the higher the ion levels. Wear is
increased in patients with smaller heads and smaller side implants. Wear
is increased in patients who have the cup placed at a steeper angle.
So, think about who gets the smaller implants? Women do as they’re
Metal Hip Problems: Even If You're Asymptomatic Doesn't Mean You Shouldn't Worry
You can have elevated chromium cobalt levels with no symptoms, no
groin pain, no hip pain and no adverse reactions. So, just because you
are asymptomatic with a metal on metal implant,
particularly with the ASR, doesn’t mean that you don’t have something
to think about in knowing what the chromium cobalt ion level is in your
hip replacement today, what it is a year from now and what it then
becomes five years from now.
One way to think about that is if it elevates, that’s an
indicator that your joint may be wearing and that you may need to have a
revision. While experts can’t make that statement definitively, it is
something that’s talked about Therefore, it's important to monitor it
because of the potential of adverse reactions systemically to the
chromium and cobalt ions.
Your orthopedic surgeon who implanted this would typically be
aware of this newer information. But, how do you have this checked? You
don’t just go to the hospital lab and get it drawn because there can be
errors in the hospital lab. Many hospital labs cannot check it. There’s
potential for contamination with a metal needle and most people may not
think about that.
According to medical experts, here's how to adequately check it.
You check it by drawing 5 cc’s of blood in a purple top anticoagulation
tube with EDTA that’s particularly anticoagulant. The way you do that is
you go to a lab that can reputably check chromium and cobalt ions.
Classically, they would draw through a metal needle the first 5cc
measurement of blood, discard that and then draw the anticoagulated
blood. That whole blood sample is frozen to a level of negative 17
degrees centigrade or below and transported for testing. Quest
diagnostics is such a lab for being able to do that and they have
locations across the country.