Metallosis occurs when the polyethylene lining that prevents the metal parts of artificial joints from creating friction and rubbing against each other wears out. The metal components come in direct contact and metallic fragments and ions become released into the surrounding tissue and blood stream. The metallic fragments and ions saturate the surrounding bone causing a painful soft tissue reaction and bone loss. Metal ions can also enter the blood and cause elevated levels of chromium and cobalt. Pain is caused by loosening of the prosthesis and the inflammatory reaction. When accompanied by elevated serum levels of chromium or cobalt, a metal hip joint likely has caused not only soft tissue reaction but a soft tissue mass or cyst as well. Artificial joints with have metal on metal components that cause pain or elevated levels of metal in the blood should be removed.
The soft tissue reaction is caused by cytokines and other inflammatory cells and mediators that arise in response to the metal leaching into the local tissue and into the blood. Levels of Chromium above 5.1 µg/L and Cobalt above 4.4 µg/L are considered toxic and an indication for removal of the implant without other symptoms. The bone around the prosthesis can dissolve causing loosening of the component stem part or cup part or both. The soft tissues become discolored and devitalized. An inflammatory mass or cyst may also from around the hip or knee joint. Most cases of metallosis occur in hips and knee joints that are malpositioned. The incorrect alignment of the prosthesis components within the bones causes abnormally excessive pressure and friction on the liner causing it to wear out. However, cases of metallosis also occur even when there is no malalignment.
Britcher Leone & Roth is helping people who have suffered injury from metal on metal hip implants and require removal and revision. Joint prostheses that can cause metallosis have been manufactured by Stryker, Zimmer and Johnson & Johnson. The average time from original implant to removal is 30 months. If you have a hip or knee implant made by Stryker, Zimmer or Johnson & Johnson that has been recalled or have developed metallosis as a result of any other implant, we can help you.