Adding more than one HediffDef?

[Ykara]

I have the problem that I can't figure out how to add more than one HediffDef to a recipe. For example, if I install a bionic arm I want it to install the arm and maybe a bionic leg too. It's a bad example but I hope you understand what I want. Does anyone know how to do this (or if it's even possible)?
Thanks in advance.