Image-guided cranial osteoma resection and bioceramic porous hydroxyapatite custom-made reconstruction in a one-step surgical procedure. Technical notes and illustrative case.

Background: Removal of a large cranial tumour and reconstruction of the consequent bone defect in the same surgical setting is an ordinary procedure. A custom-made hydroxyapatite ceramic reconstruction of a cranial bone defect is a modern option that currently needs a preoperative stage of studying the bone defect and designing the implant. Consequently, if a reconstructive hydroxyapatite-based procedure after a cranial tumour resection is the aim, a two-stage surgery is necessary. The authors investigated the possibility of performing this procedure in a one-step surgery by the use of a neuronavigation system. Methods: Preoperatively, an epoxy-resin model is built by stereolithography on three-dimensional (3D) cranial computed tomographic (CT) scan data of the patient affected by the cranial tumour. Afterwards, the implant is designed on the base of the planned bone flap that the surgeon simulates on the model for the tumour resection. The CT scan of the patient is fused in the neuronavigational system with a 3D cranial CT scan performed on the model without the planned bone flap. Intra-operatively, the surgeon is guided by the neuronavigational system to remove the cranial tumour through the craniotomy preoperatively planned on the model and, for this reason, perfectly matching the prosthesis for shape and size. Results: In an illustrative case, a 26-year-old woman presented to the authors' attention for a large growing fronto-temporal osteoma. Because of the site of the tumour and the consequent challenging reconstruction of the bone defect, it was decided to attempt the cranioplasty with a custom-made hydroxyapatite ceramic implant. The removal of the osteoma and reconstruction with a hydroxyapatite ceramic implant was done in a one-step surgery. Seriate postoperative cranial CT scans showed a satisfying 3D result. Conclusions: Surgical removal of a cranial bone tumour and optimal reconstruction with a custom-made hydroxyapatite ceramic implant is an appealing procedure that can be carried out in a one-step surgery by means of an intraoperative image-guidance system.