抽象的な

The evaluation of bio-mechanical properties of four different skull implants by finite element methods

Zhigang Wan, Chiwen Huang, Yunqing Li, Caihong Wan, Rongde Zhong

Cranioplasty helps to restore skull’s integrity, stability the state of the intracranial structure, also to improve the aesthetic immensely and reduce the concerns caused by weakened of brain protection with decompressive craniectomy. By using stress-strain analyzing of the finite element methods, to analyse the shock resistance, ability of absorbing concussion and the stability after the implanting of four different skull implants, in the end to select the implant with the one with the best biological-mechanical properties combined with CT data of 2D imaging and computer-aided design technology to establish four implants: a. conventional 3D blanket titanium mesh; b. conventional wedge-shaped PEEK mesh; c. 3D blanket triangular parabolic titanium mesh with hole button; d. half wedge-shaped triangular parabolic PEEK mesh with hole button. To second by importing ansys-workbench 17.0 software, loading adding a 500N static force at the center of the implants area of 3.982 cm² which simulate four different scenarios of the implants suffering a real impact of heavy weight or vehicles. Comparing stress distribution, the maximum stress, the strain distribution and the maximum deflection of four different implants and the corresponding defective skulls. Under 500N load force, both four implants and defective skulls didn’t have breakdown or deformation, On the models a and c the stress concentrated at the temporal region of skull base. Pars orbitalis and the connecting areas by implants and defective skulls and the points of strength of the prosthesises. On the model b, the stress concentrated at the frontoparietal, the points of strength of the prosthesis, temporal region of skull base and titanium strip. The outcome of the model d is similar to the case b, but without obvious stress concentration of triangular parabolic mesh with hole button. The σ and ε of implants a-d are respectively: 243.800 mpa; 21.002 mpa; 386.200 mpa; 2.731 mpa and 0.1644 mm; 0.0825 mm, 0.2782 mm, 0.0828 mm. The σ of defective skulls c is 6.039 mpa, its ε is 0.0408 mm. The σ and ε of th defective skulls of d are accordingly 1.829 mpa and 0.0175 mm. The mechanical properties of PEEK are superior to the titanium implant. It can take the better role of brain protection. D of four prosthesis demonstrates the best ability in the biomechanics, followed by the b.