January 4, 2011
Patients who received DePuy ASR Acetabular hip replacement systems have increasingly been asking their doctors for blood tests to check the level of heavy metal in their systems. Several have made the worrying discovery that their cobalt levels are far above normal. But many are confused about the information. How much cobalt is normal, after all? Is any level of cobalt cause for concern? At what point does one really have to worry about serious consequences?
This article endeavors to answer that question to the best of our ability.
How Much Cobalt Is Normal?
If you go to a doctor and get a blood test, the amount of metal (including cobalt) in your bloodstream will be calculated in micrograms per liter. A healthy person has a normal cobalt range of .19 to .4 micrograms per liter (or parts per billion) . The metal in your bloodstream only presents in very, very small amounts; someone with normal cobalt levels could gather all the cobalt in their system together and come up with an amount smaller than a grain of sand.
Even at highly toxic levels, the actual amount of cobalt looks very, very tiny. 1 microgram per liter of cobalt is considered a low toxic level. That's about five grains of sand in a giant bucket of water. Seems small - but those tiny grains of metal can throw the entire chemistry of your body wildly out of order.
In Britain, there are regulations for keeping close observations on patients who have metal-on-metal bearings in any hip implants, including the ASR hip implants. At cobalt levels of 7 micrograms per liter, patients must be kept under observations. Symptoms at those levels include hip pain, dying tissue, and pseudotumors - masses under the skin. Generally doctors recommend revision if a patient with a hip implant has a cobalt concentration between 7 to 19 micrograms per liter .
Is Any Level of Cobalt Cause for Concern?
No; cobalt is a naturally occurring element in nature and is actually essential to several of your body's basic functions. It interacts with both vitamins C and B12 so that they can be absorbed into your system. B12 is particularly important to your body, since it is necessary to form red blood cells.
Without cobalt, you wouldn't be able to produce red blood cells, which means you wouldn't be able to get oxygen to all of your body's tissues. It's a pretty essential element to have in your body - in normal levels, of course.
If you have excessively low levels of cobalt, your body has difficulty absorbing B12 and creating red blood cells, which can ultimately lead to anemia. If you have excessively high levels of cobalt, the result is cobalt poisoning, which has a slew of other toxic effects.
What is Cobalt Poisoning?
Cobalt is one of the many metals that is found naturally in the body, but as with all other metals, in excess amounts it becomes toxic and leads to many harmful and potentially permanent side effects. Cobalt poisoning has caused cardiomyopathy, hypothyroidism, and neurological damage as well as impairing the senses. It can cause neuropathy, seizures, blindness, headaches, and liver damage. Cobalt has also been linked to cancer.
For DePuy hip implant recipients, it can also mean that future hip revisions have a lower chance of success. Excess amounts of cobalt in the bloodstream lead to metal sensitivity and metallosis, which can seriously damage surrounding tissue and make a second implant less likely to succeed.
Normal levels are between 0.19-0.4 micrograms per liter, but it is very common for people who have prosthetics made of metal (like the DePuy ASR Acetabular system) to have slightly elevated levels as a side effect. Cobalt levels are not considered toxic until they reach 1 micrograms per liter. It is likely your doctor would recommend hip revision surgery between 7 to 19 micrograms per liter.
What Should You Do?
If you have a DePuy ASR Acetabular hip implant and are concerned about cobalt poisoning, see your doctor as soon as possible to discuss your options and express your concerns. Our medical crib sheet for DePuy ASR hip implant patients can give you some guidance on questions you may want to ask your doctor and tests you may wish to request.
If you'd like some advice on any legal case you may have against DePuy because of the danger this implant may present to your current and future health, we're here to answer any questions you may have. Call our offices at 1-800-677-7095 or use our online contact form, and we'll do everything in our power to get you the answers you need.
To learn more about the problems associated with the DePuy ASR Acetabular hip implant, these articles may prove helpful:
DePuy Asks Hip Implant Patients to Sign Away Their Legal Rights
Glossary of Medical Terms Related to the DePuy ASR Acetabular System
How the ASR XL Acetabular System is Constructed