Early this year, DePuy issued their recall for the ASR XL Acetabular System sold
in the United States. Doctors began recommending revision surgery to those of their
patients who reported pain or an overall failure of the DePuy hip implant. In many
cases, the doctor was wise enough to run a blood test to determine whether there
was excess metal in the bloodstream, as many medical studies have shown that elevated
levels of metal are common for patients with metal-on-metal hip implants.
Patient after patient with the ASR Acetabular DePuy hip implant began turning up
with cobalt and chromium levels that were well over 100 times normal.
Cobalt poisoning has
been getting a great deal of attention and for good reason: the symptoms of cobalt
poisoning include many serious side effects including neurological (brain) damage,
heart irregularities, and seizures. Cobalt poisoning has also been linked to cancer.
It's small wonder that many people, when they first learn that the DePuy hip implant
leaks metal ions into the body, are primarily concerned about cobalt poisoning.
However, chromium poisoning is equally dangerous. And the symptoms are just as troubling.
What is Hexavalent Chromium?
When discussing chromium poisoning, the most significant problems have been linked
to a particular compound, hexavalent chromium (Chromium (VI)). Hexavalent chromium
is the agent that turned up in the water supply of the California town of Hinckley,
later made famous by Erin Brockovich's activism work. Many people remember the Erin
Brockovich story - if not for the event itself, certainly for the award-winning
movie based on it. They remember that there were many cases of cancer in the town;
196, to be precise.
Few of them remember that the problem with the water was hexavalent chromium.
Hexavalent chromium has been deemed a cancer-causing agent by the World Health Organization,
which means that both chromium and cobalt can elevate a DePuy hip implant patient's
cancer risk. In fact, studies show that elevated levels of any heavy metal
increase the risk of cancer.
Our research indicates that hexavalent chromium is the type of chromium being released
by the ASR Acetabular system; it degrades in the body into trivalent chromium, or
Chromium (III). Anywhere from 18-30% of a typical metal-on-metal implant is composed
of chromium; we do not have current numbers on the amount of chromium included in
the DePuy hip implant.
Patients with elevated chromium levels show similar symptoms as those with elevated
cobalt levels. There are notable differences; cobalt poisoning can cause cardiomyopathy,
for example, while elevated chromium levels do not appear to cause heart problems
but can cause problems with the reproductive system. The table below gives an overview
of the symptoms shown by patients with elevated chromium levels vs. those with elevated
cobalt levels.
If a particular type of chromium or cobalt has been specifically linked to a symptom,
it is noted in parentheses next to the symptom. For example, mutated DNA is noted
as being linked specifically to Chromium III.
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Elevated Cobalt (Co) Levels
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Elevated Chromium (Cr) Level
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Genetic Information
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- Inability to repair DNA, reduce gene expression Co (II)
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- Inability to repair DNA, reduced gene expression Cr (VI)
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Localized tissue around the implant
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- Infiltration of lymphocytes
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- Infiltration of lymphocytes
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Liver
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- Necrosis at high levels of Cr (VI)
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Kidney
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- Can impair liver function
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Respiratory System
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Nervous System
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Heart and Vascular Systems
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Endocrine System
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- Potential to alter the production of sex hormones Co (II)
- Potential to induce hypothyroidism Co(II)
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- Potential to alter the production of sex hormones Cr (VI)
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Visual and Auditory System
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Reproductive System
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- Abnormalities in sperm Cr (VI)
- Reduced number of follicles Cr (VI)
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Carcinogenesis
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- May lead to an increased risk of cancer
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- May lead to an increased risk of cancer
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What Does This Mean for My Health?
Chromium poisoning and cobalt poisoning are both very serious; however, there is
no way to tell if you have either problem without getting a blood test to find out
what your chromium and cobalt levels are. Even if you have elevated levels, you
may still not have chromium or cobalt poisoning; slightly elevated levels are normal
for patients who have metal-on-metal hip implants and among the doctors we've consulted,
they do not consider slightly elevated levels to be cause for alarm.
For those DePuy hip implant patients who have presented with 100 and 500 times the
normal level of these two metals in their systems, however, doctors are quite concerned.
Cobalt and chromium can both be retained in the bodily tissues for a long period
of time, and if the body is subjected to excess levels, it will have a more difficult
time processing the metal ions through the normal elimination process, especially
if the kidneys are damaged - a problem sometimes caused by chromium poisoning. Little
research has been done on the long-term effects of elevated metal ion concentrations.
When speaking to your doctor, we have a medical crib sheet that may be
prove useful if you are uncertain what to ask about or worried you may forget important
questions. We would also highly recommend you read this article on DePuy trying to get patients to agree to give
the company access to their medical records; if you are thinking of pursuing
a legal case against DePuy, signing away your medical records can be severely detrimental
to your case.
The health risks you've been asked to shoulder are immense and surely very upsetting;
we will do our best to help in any way we can.
Recommended Readings:
Hip Implant Risks May Include Premature Failure
How the ASR XL Acetabular System is Constructed
DePuy Asks Hip Implant Patients to Sign Away Their Legal Rights
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