Titanium cranioplasty using 3-D computer modelling of skull defects

The ideal prosthesis for cranial defect repair is the original bone flap, but for various reasons this is not always available. Creation of prostheses has been an inexact and difficult science, particularly for complex and cosmetically important defects. Poorly shaped prostheses are difficult to insert and secure. In addition, the resultant deformity may lead to scalp necrosis and infection. The need for precision-fitting prostheses has prompted the development of several computer-aided methods of cranioplasty plate manufacture. Defects have been modelled from CT scan data using stacked slices, computer-driven milling and selective laser sintering. We report our experience with titanium cranioplasty plates manufactured using these methods. The plates fit even the most complex defects, are easy to insert, and produce excellent cosmetic results. There has been no postoperative scalp necrosis or infection. The cost and time involved may currently preclude the routine use of computer modelling of defects, but as equipment costs and production time diminish, this may become the standard allograft cranioplasty technique.