The DePuy ASR Metal-on-Metal Hip Implant: A Scientific Analysis of its Problems

The last ten years have seen surgical replacement of hip joints with an artificial prosthesis increase significantly. The main reason for this surge in hip replacement surgeries is our aging population. With people living longer, more active lives, degenerating hip joints can put a halt to that activity. From 1997 through 2004, the number of hip replacement surgeries increased nearly 50% and if the trend continues it is estimated that the annual number of hip replacements in the United States will reach 600,000 by 2015.

Factors in Hip Replacement Surgery

Primary reasons for patients undergoing hip replacement surgery include chronic pain, impairment of daily functions and severe arthritis in the hip joint. The most common type of arthritis leading to total hip replacement is osteoarthritis and is generally seen with aging or trauma to the hip joint. In some instances necrosis of the hip can be present, usually caused by a fracture, alcoholism, lupus, or taking steroid drugs such as prednisone. Patients may experience progressively worsening chronic pain which prohibits them from walking, climbing stairs or even getting up from a sitting position.

Types of Hip Implants

There are many different types of hip replacement implant including the metal-on metal, metal-on-polyethylene and metal-on-ceramic as well as the implants which are 100% ceramic or polyethylene. Other than the materials the implant is constructed with, the only other major difference is in how the implant is affixed—it can be cemented to the bone or attached in such a manner that it grows into the patient’s remaining bone. The idea behind the cobalt and chromium metal-on-metal hip implant was to create an implant which would not have to be re-done for fifteen to twenty years—unlike the ceramic and polyethylene hip implants which last approximately 8-12 years.

Depuy Hip Implant Danger

What is Metallosis? 

Home | Personal Injury | DePuy Hip Recall | Traffic Tickets | Family Law | Criminal Defense |Get Informed

 

Metallosis occurs when metallic debris builds up in the periprosthetic soft tissues. In the case of the DePuy ASR Acetabular system, the two parts of the hip implant abraded against one another, creating friction and releasing metallic ions of cobalt and chromium into the body. Those microscopic metal ions cause an autoimmune response. The immune system identifies the metal ions as foreign bodies and automatically inflames the area around the debris. The body is essentially trying to "trap" the foreign particles in the inflamed area so that the metal can't spread to the rest of the body. In the case of the DePuy hip implant, it appears that the immune system sends inflammatory cells to the synovial membrane as well, causing synovitis. Synovitis is generally quite painful, since the membrane is too inflamed to allow the joint to rotate properly. Metallosis can be complicated by metal sensitivity, which is essentially an allergic reaction to metal. The normal autoimmune response to foreign matter in the body is to inflame the area and attack the foreign cells. When the body is hypersensitive to a particular substance (like metal), the immune system overreacts and multiplies its efforts to eliminate the foreign body. In the process, normal healthy tissue can get caught in the crossfire as the body mounts an ever-growing campaign against the foreign body. In patients with a DePuy ASR Acetabular System, the immune system is fighting a losing battle, even after its efforts are multiplied through metal sensitivity. Your white blood cells (leukocytes) attack any foreign organism, but they also "tag" and remember the organisms that have attempted to invade before and come up with secretions designed to wipe out those specific invaders. In the ASR hip implant, the device's friction constantly releases new metal ions into the bloodstream, which means the immune system continually receives a message that its efforts are not enough to eliminate the foreign matter.  A simple analogy for the metallosis is a food allergy, which occurs when the body identifies a food as so dangerous to the body that its autoimmune reaction is exaggerated. Essentially, it identifies the food as a poison and reacts strongly so that the brain will realize the food is dangerous and move the body away from it. In extreme allergies, the body's immune response can be so overly strong that it can actually kill the person.  Generally, this sort of over-reaction occurs if the immune system is completely unfamiliar with a foreign body and can find no parallels with other objects it has encountered in the past. It can also occur if the body is over-subjected to the object; for example, it is possible to give yourself an allergy to just about any food if you consume excess amounts for months at a time.  Symptoms of metallosis generally include pain around the site of the implant, pseudotumors (a mass of inflamed cells that resembles a tumor but is in fact merely collected fluid), and a noticeable rash that indicates dying tissue. The damaged and inflamed tissue can also contribute to loosening the implant or causing dislocation, since the tissue that would normally hold the implant in place is weakened.  Women, the small in stature, and the obese are at greater risk for metallosis because their body structure causes more tension on the implant and contributes to the release of the metal ions into the bloodstream.  If you're concerned that you have an ASR XL Acetabular hip implant and would like to speak to someone about getting compensation for your medical problems now and in the future, please give our offices a call at 800-730-7607 or  fill out our online form. We're here to answer any questions you have and advise you of your rights.

DePuy ASR Hip Implants Risk

Cobalt Poisoning: DePuy ASR Hip Implants Are a Serious Risk 

Home | Personal Injury | DePuy Hip Recall | Traffic Tickets | Family Law | Criminal Defense |Get Informed

A person with 1 microgram of cobalt in their bloodstream has nothing to worry about.  Someone whose blood contains more than 25 micrograms has cobalt poisoning. And a patient whose blood contains more than 100 micrograms? Probably has a DePuy ASR hip implant. As more and more patients who received DePuy ASR Acetabular hip replacement systems ask their doctors for blood tests, the numbers of people who have extraordinarily high levels of cobalt in their bloodstreams become staggering. Several of our own clients have received the worrying news that their cobalt levels are far above normal, and at least one doctor has published a case study of two DePuy hip implant recipients who have cobalt levels that are 100 to 500 times normal. 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 deciliter. A healthy person has approximately 0.019 micrograms per deciliter - about one microgram for their entire body. 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. 0.5 micrograms per deciliter of cobalt is considered toxic. 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 0.7 micrograms per deciliter, 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 of 1.9 micrograms/deciliter or above. Revision isn't suggested until cobalt concentrations are one hundred times the mean average - even though levels are considered toxic at twenty-five times the average. One patient with severe cobalt poisoning had levels of 6.6 micrograms/deciliter. That's nearly three hundred and fifty times the mean average. The dangers of cobalt levels so high were quite apparent: in addition to hip pain, the patient showed declining cognitive function, was losing control of his senses like hearing and sight, suffered from seizures, heart failure, and multiple other problems. The amount of cobalt that patient had in his blood was still small enough that it wouldn't have filled a teaspoon. But the damage was great enough to threaten his life. 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. Doctors Unaware of Risk  For many patients with DePuy ASR hip implants, the symptoms of cobalt poisoning either go unnoticed initially or are chalked up to other pain and problems related to the hip implant failure. For example, a patient might have deteriorating mental function, mood disorders, or vertigo -  but if the patient is also in a great deal of pain because the hip implant is failing, it is very possible that he might assume the other symptoms are related to his pain and will go away if he has a revision surgery. Meanwhile, doctors who are fully aware that DePuy ASR XL Acetabular System is failing at inordinate rates may recommend a revision surgery to solve problems of pain and inflammation. Those doctors may not know that the friction of the hip implant is releasing excess amounts of metal ions into the bloodstream and causing potential problems with far more long-reaching effects. A patient could walk out of surgery with heavy metal poisoning - and not be aware until the symptoms become extreme enough to return to the hospital. 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.