Pyrolytic Carbon use

[boneguy]

Does anyone know why the use of pyrolytic carbon has been limited to small joints?

China has been looking at the use of pyrolytic carbon in hip replacements and has good success. Europe and the US have been focused on metal and ceramics, why?

 

[burdulis]

Primarily because pyrolytic carbon is deposited on a low strength substrate and has high residual stress due to the coating process. US companies have made implants but they have not been very succesful. It's pretty risky introducing new technology in the US (Liability, regulatory) and the combination of potential failure and long regulatory process (PMA) means that it's easier to use metal on metal or ceramic on metal because the likelyhood of failure is less and regulatory path is easier (metal on metal is pre '76 so is a 510k rather than PMA). Europe is generally more accepting of new technology (ie risk) in medicine (less litigenous society) and the regulatory hurdles are lower

 

[southampton]

I agree with what burdulis said. I would add that the technology for the manufacturing of pyrolytic carbon in the U.S. is largely fluidized bed reactors, which will only work econmically with relatively small parts. Something the size of a hip joint, while not impossible to produce, is a very different challenge from making a finger joint or a heart valve.

 

[boneguy]

Thank you for the responses, they are both very good points.

With excellent biocompatibility and a reduction in stress sheilding pyrolytic carbon is a very attractive material. Decreased wear debris appears to be an advantage as well. Other than the expense of an IDE required by the FDA the biggest concern I hear is instrumentation.

Have instruments been related to implant failures with any of the current produces on the market? If so, what is the failure rate?