April 18, 2013

When Stryker Hip Implant Patients Develop Pseudotumors



Pseudotumors are typically large, solid or semi-liquid masses which can form around an artificial hip implant device and can mimic the effects of infection. While pseudotumors are neither infective nor cancerous, they may be reacting to the metals in a hip implant or simply to the presence of a foreign body—no matter what it is constructed of. It appears from research done on hip implant devices that pseudotumors are more likely to form around implants which are either all-metal or have metal parts although they may also form around ceramic and polyethylene implants. When hip implant problems become apparent, a pseudotumor may have been present for a significant length of time.

The Stryker Rejuvenate and ABG II both implement a metal neck juncture in the design and have metal trunnions located on either end of the stem piece. Body fluids can become trapped under the trundles or at the neck juncture, leading to corrosion and fretting. When the hip implant devices suffer corrosion, premature wear can result. In turn, this premature wear releases metal debris into the surrounding hip tissues and bloodstream. Chromium and cobalt toxicity are often found among patients with metal hip implants or those with metal parts such as the Rejuvenate and ABG II. The Stryker hip replacement recall for the Rejuvenate and ABG II was issued in July, 2012, resulting in lawsuits against the company. It is advisable for anyone considering implantation of a metal hip device to be tested for metal sensitivities prior to the surgery. Metal poisoning can lead to a wide variety of serious health symptoms including:

·         Cardiovascular, renal, thyroid and gastrointestinal disorders
·         Diminished hearing or vision
·         Anxiety, depression or irritability
·         Vertigo or other balance issues
·         Memory loss
·         Disruption of DNA
·         Skin problems
·         Neurological issues

Women appear to have a higher risk of developing pseudotumors as do those with a higher-than- normal sensitivity to metals. Considering that among the general population the prevalence of skin reactions to jewelry containing nickel is relatively high—10 percent—it can be expected that a significant number of adults receiving implants will be particularly sensitive to the cobalt and chromium. The smaller component sizes of hip implants required in women are known to be associated with increased wear and are less forgiving to any level of malposition. Women who suffer from premature arthritis may also present during hip surgery with acetabular dysplasia or an abnormal socket inclination.

In many cases pseudotumors will cause neither pain nor abnormal hip mobility and can go unrecognized for months or even years. Once a pseudotumor is discovered, it is likely to have caused significant tissue damage and will require surgery to remove. The most common symptoms from pseudotumors are chronic pain, diminished range of motion, inflammation in the hip joint and difficulty walking or engaging in normal everyday activities. In some cases a pseudotumor can cause a localized rash and a lump may be apparent. A pseudotumor may be explained as the body’s reaction to a foreign body—in this case the metal, ceramic or polyethylene hip implant.  In one study of hip implant devices metal particles were found in every case of pseudotumor development. Although malposition of the implant was suggested, many properly positioned implants showed evidence of pseudotumor development. Blood poisoning from metal toxicity can greatly increase the severity of the pseudotumors, and revision surgery is almost a given in the presence of pseudotumors. Any recipient of an artificial hip, particularly those which are all-metal or have metal components, should undergo x-rays, MRIs and blood testing to determine whether cobalt and chromium toxicity or pseudotumors are present.