Is this going to be your second surgery? What do you mean the bone is gone? I remember early on in my Chiari journey one report said I already had a decompression surgery but my skull was just very thin in that area.
Hi and welcome to the Chiari forum.
I am not sure what bone is already gone, but they usually chip bone from C1 and C2....
Mesh is not widely used to hold the tonsils in place......and your Dr should have informed you as to how they do the procedure...as they all tend to have their own ways.....
Do you have a CSF obstruction or any related conditions?
When is your surgery scheduled for?