Biomedical Engineering Experts Discuss Failure of Carbon Fiber Fixation Device

Biomedical Engineering Expert WitnessThis case involves a patient who had a carbon fiber plate implanted in her leg to treat a fracture. At some point, the plate broke, and the coating material allegedly “melted” while inside of her. The plate was black in color upon insertion into Plaintiff. After the plate broke, the Plaintiff claimed to have had black material oozing out of her leg. When the plate was finally removed, it was white in color. It was alleged that the plate had been negligently designed and/or manufactured, and that the materials used were not suitable for use in the human body due to their demonstrated inability to withstand the conditions encountered there.

Question(s) For Expert Witness

  • 1. Do you have familiarity with carbon fiber implants?
  • 2. Are you able to review the case and determine if there were any flaws in design, and help determine why the plate turned white?

Expert Witness Response E-038002

I have a PhD in Biomedical Engineering from Mississippi State University and 39 years of experience in medical device research, including 10 years at an orthopedic device company. I am program director for a graduate program in Biomedical Materials Science and teach a 2-semester course in Biomaterials. I do have familiarity with carbon fiber reinforced polymer implants. I was the research leader for the carbon fiber/polylactide ligament repair scaffold and attachment bollard for a major medical device company, where I was also involved in the team working on a carbon fiber reinforced Polysulfone hip replacement device. My initial thoughts are that I am not sure why the device would have turned white, since it would seem impossible to turn carbon fibers any color except black. I do not believe that any part of the device “melted”, since the polymer involved has a melting temperature of approximately 650 degrees F, 340 C. I am not aware of a physiological process that could dissolve the polymer either.

Expert Witness Response E-010885

I am experienced multi-discipline engineer and doctor of medical science. My expertise includes the analysis of complex systems, designs and failures involving materials, mechanical and medical systems. I am actively involved in design, product development and research. I am familiar with carbon fiber implants and Carbofix Orthopedics and their devices. This includes experience with PEEK and Carbon fiber reinforced implants and medical devices. I am aware of the issue of wear debris generation with Carbofix implants at the interface between the carbon fiber and metal screw junction. This results in black fiber and PEEK particle generation. I also designed and tested a carbon fiber implant rod while I was a researcher at the VA.I would be happy to review your case. I have not seen the color loss described but am familiar with the history of carbon fiber migration in carbon fiber implants.


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