Use of a 3D Skull Model to Improve Accuracy in Cranioplasty for Autologous Flap Resorption in a 3-Year-Old Child: Technical Note

Aims: Cranioplasty is considered a simple reconstructive procedure, usually performed in a single stage. In some clinical conditions, such as in children with multifocal flap osteolysis, it could represent a surgical challenge. In these patients, the partially resorbed autologous flap should be removed and replaced with a pre-customed prosthesis which should perfectly match the expected bone defect.

Here we describe the use of image integrating of a 3D skull model to improve accuracy for single stage hydroxyapatite cranioplasty, in a child with multifocal bone flap osteolysis following autologous cranioplasty.

Methods: Pre-operatively a 3D cranial CT scan was performed according to the implant producer's protocol (Custom Bone^®, Finceramica, Italy). The surgical implant was designed by the surgeons to cover the entire zone of the partially resorbed flap. An epoxy-resin model used for a pre-operative 3D Ct scan acquisition. The cranial 3D CT scan of the patient was than merged with the CT scan of the epoxy-resin model using the Stealth Merge Cranial Synergy^® Software (Medtronic, USA). Surgical instruments were navigated with the Suretrack^® technology (Medtronic, USA) for precise craniotomy. Appropriate image windowing allowed navigated bone resection. Thus, we were able to match perfectly the prosthesis for shape and size.

Results: A 3 years old child presented with a left fronto-temporo-parietal bone flap resorption 2 years after autologous cranioplasty.

The patient presented with multiple sites of bone resorption of the flap. Due to the complexity of bone defect, we decided for a single stage procedure using an image merged procedure for hydroxyapatite ceramic prosthesis implantation. The postoperative period was uneventful. The aesthetic result at 3 months was judged to be excellent both by the surgical team and the parents.

Conclusions: Bone flap resorption is a frequent complication in the pediatric age group and a major reason of reoperation after autologous cranioplasty in children. This condition may require complex reconstructive solutions to achieve optimal anatomical results. Hydroxyapatite ceramic cranioplasty implemented with image merge navigation of a 3D skull model allows a single stage reconstruction in case of complex vault defects with excellent results.