Skull Mechanics Study of PI Procedure Plan for Craniosynostosis Correction Based on Finite Element Method

The main purpose of correction craniosynostosis is to reopen cranial sutures with some bone slots in order to free the skull transformation with the brain development from the closed craniums. The intent of this paper is to analysis the relationship between the shapes of bone slots and the skull rigidity. Finite element method is utilized to obtain the stress distribution and deformation clouds of the different surgery schemes. And then a best cranial suture bone slot´s shape is brought up according to the stress distribution simulation results. Methods: A Congenital craniosynostosis case is selected to design the surgery treatment plan. PI-shape craniosynostosis correction scheme is used, and bone slots used for reconstruction the cranial suture are in variance to simulate the stress distribution change after the slots shape change. The cranial bone and endocranium models are meshed as tetrahedron element for finite element analysis. For the instantaneous stress take into account when the slots shape change, the viscoelastic material properties of the crianial bone and endocranium are ignored here. Abaqus is used to calculate the stress result. Results: Different bone slot shapes induce different cranium stress distribution and skull rigidity. Appropriate bone slots as the new cranial suture can make the cranium to win the maximum stress value about 46.12Mpa and the maximum displacement about 10.25mm. Conclusion: The results of stress distribution and deformation of cranial bone under the intracranial pressure after the correction craniosynostosis operation can be obtained by the finite element method. These results reflect the ability of the cranial bone expanding with the brain tissues growth. With finite element method, surgical prediction can be made to guide surgeons to make the decision of improving surgical treatment.