Q: I had considering having a revisional PMMA cranioplasty as I am dissatisfied with the results of my first one. There are bumps and irregularities across my forehead. I have been advised before that getting a flush integration of the material to the bone, with respect to the edge of the material and the surrounding bone, is difficult to accomplish. This is evident in my current implant where I can really feel the edge of the material especially around the top part of my head where there is very visible indention where the material is raised from the rest of my head and also on the right lateral portion of my forehead where there is a large visible lump. Without considering the presence of the scar, this visible raised portion makes wearing my hair short impossible. If you were to perform secondary cranioplastic surgery can you achieve a smooth finish with the implant and surrounding bone and how would you address the problem of tapering the existing PMMA material. Would you shave it down? Remove it and re-apply? Add more material to surrounding bone and then feather it off???
A: The key to getting a good edge and smoothness of PMMA in a revisional cranioplasty is to add it, allow it to set, and then using a handpiece and burr to carefully feather and smooth all edges. While it is tedious to do and causes a lot of shave debris, it is essential to do this step. You must have perfectly smooth edges that blend perfectly in all directions or you will have visible edges later when the swelling goes down. Even though the scalp is thick and seems like it would hide any bumps or edges, it will not once the swelling goes away and the skin contracts down to the implanted material. One has to remember that the skull is smooth for a reason, even if one doesn’t like its original shape.
Dr. Barry Eppley