骨性隧道内植皮后挛缩的三维有限元分析

目的:建立小型猪下颌骨骨性隧道内植皮的有限元模型,以了解骨性隧道内植皮后挛缩的生物力学基础和形变规律。方法:将小型猪下颌骨钻孔形成骨性隧道并移植全厚皮片,通过CT获取移植即刻及移植后2周、4周、6周、8周的骨性隧道内植皮数据,利用MIMICS 10.1和ANSYS 12.0软件建立猪下颌骨钻孔形成骨性隧道的三维有限元模型,仿真分析骨性隧道内植皮后的挛缩过程,计算节点位移及施加应力,获取骨性隧道内植皮挛缩的生物力学基础和形变规律。结果:通过小型猪下颌骨骨性隧道内植皮的有限元分析模型可以直观有效模拟节点位移及施加应力,其仿真分析结果与动物实验几何外形相似程度高,细节损失小;经静力分析发现0周到4周的挛缩过程所受应力的大小约为4周到8周的挛缩过程所受应力大小的6倍,所受应力的方向都是指向隧道中心。结论:有限元分析可以模拟骨性隧道内植皮的挛缩过程,分析骨性隧道内植皮后挛缩局部区域的应力分布及大小,协助临床设计挛缩对抗方案。

Three-dimensional finite element analysis of the skin graft contracture in bony tunnel

Objective To establish a finite element model of the skin graft in bony tunnel of mini-pig mandible,and to evaluate its biomechanics and deformation.Methods Mini-pig mandible was drilled to form a bony tunnel and then full thickness skin graft transplantation was performed.The data of DICOM format was obtained by CT scan when and after transplantation including 2 weeks,4 weeks,6 weeks and 8 weeks.The finite element model was established and the contracture process was analyzed via MIMICS 10.1 and ANSYS 12.0.The nodal displacement and stress was calculated to evaluate its biomechanics and deformation.Results The finite element mode can achieve a good similarity of geometric shape and simulate the nodal displacement and stress.The stress size of the first four weeks was about six times of the later four weeks.The stress was pointed to the tunnel center.Conclusion The finite element analysis can simulate the process of contracture and calculate the stress distribution and its size,which could guide the postoperative design to reduce the contracture.