Thursday, November 25, 2010

Metallosis (excerpts)

Metallosis is usually defined as aseptic fibrosis, local necrosis, or loosening of a device secondary to metallic corrosion and release of wear debris.

Numerous factors lead to polyethylene wear, which subsequently affects primary THA survival. Progressive polyethylene wear is associated with the occurrence of osteolysis, especially overlying the acetabulum, which can lead to component loosening and subsequent revision.

According to a report at, the DePuy devices have been linked to a condition called metallosis. When two metals rub together, as they do with these joint replacement devices, they release dangerous levels of chromium and cobalt ions.

At least 3.4 percent of British patients observed for a recent study of the effects and risks of metallosis eventually developed the condition. The risk is high with these devices - recalled in August - because the natural motion of the hip causes these two metals pieces to rub together constantly, creating tremendous amounts of friction.

Doctors say that the metal toxicity from chromium and cobalt debris entering their blood stream and causing serious injury may affect all DePuy hip patients.

Here is a linnk to a study often cited on the relationship between Metallosis and loosening of the replacement joint: “periprosthetic osteolysis and aseptic loosening in hips with a metal-on-metal articulation are possibly associated with hypersensitivity to metal debris.”

A great article by Taylor Lindstrom on this subject appears at:

Generally, I excerpt key issues from longer posts if I find something of interest but this is such a great description on how metallosis is caused that I thought it was worth having you read it. I reprinted this article in its entirety in the post below.



    my m/m hip was put in in the year 2000.
    by 2001 up to 77.77ppb cobalt, other metals followed, and raised and stayed in me for SEVEN YEARS. I am so sick, and the people I need to help me get better, wont touch me because everyone is afraid of a lawsuit! I really need help. JK

  2. HI,

    what kind of help do you need? are you saying the surgeon who placed the hip in orginally won't see you?

  3. The wild card in this whole mess is the toxic effects of metalosis which at this time is not completely known.I worked for 33 years as a forensic toxicologist and I know that the only way to flesh out the real toxicity of cobalt and chromium is thru extensive epidemiologic studies which are labor intensive,expensive,and time consuming.As far as I am aware no one is seriously engaged in the epidemiology and I predict if it is ever properly done it will be long after the initial litigation has concluded.