Biomechanical Effects of Cranioplasty for Defects Using Autogenous Calvarial Bone

Abstract

Harvesting autogenous calvarial bone grafts can potentially weaken the donor site and make it more susceptible to trauma. Conversely, restoring the integrity of the cranial vault structure can result in better dissipation of traumatic energy. This study proposes to mathematically model traumatic situations to evaluate the effect of cranioplasty on biomechanical properties of the craniofacial skeleton. Preoperative and 6-month postoperative computed tomography-generated DICOM data were used to extract a tetrahedral volumetric representation of the craniofacial skeleton. These data were then used in finite element solver-simulating traumatic events. Deformational stresses accumulate around defect edges and can serve as seed points for calvarial fractures at much lower energy levels in the preoperative models when compared to the postoperative models. Accumulation of stresses in the orbital roof/medial orbital wall areas was observed, similar to fracture patterns observed in the younger pediatric population Restoring architectural integrity of the craniofacial skeleton results in significant increased resistance to deformational stresses despite structural weakening caused by harvesting cranial bone.