Q: Dr. Eppley, I am inquiring about a natural method for cranioplasty. I have a forehead defect including a hole through the bone from a prior craniotomy for a brain tumor. The size of the forehead defect measures about 9 x 2 cms and represents the area where the bone flap appears to have settled inward. Can I use my own bone to reconstruct this forehead defect area?
A: Cranial bone flaps, despite using rigid fixation, can heal inconsistently or undergo some resorption leaving an outer contour depression. There are multiple ways to do a cosmetic or reconstructive cranioplasty with a variety of materials, bone being one of the options. If the defect is small enough, one could use natural bone, in other words cranial bone grafts. While natural bone has understandable appeal, it is actually not the best way to do most cranioplasties. Besides having to harvest the bone (and creating another bone defect), bone grafts are notoriously unreliable and predisposed to incomplete or total bone resorption particularly when used as an onlay. The more reliable way to perform most cranioplasties is to use hydroxyapatite cements. They are structurally stable, do not resorb and can be shaped perfectly to any defect whether it is an inlay, onlay or a combined cranial defect. They are also composed of hydroxyapatite, a calcium phosphate mineral, which is highly biocompatible with natural bone. While bone will never truly grow into it and replace it, bone will bond directly to it. The type of forehead defect that you have would do well with a hydroxyapatite cement cranioplasty.
Dr. Barry Eppley