选择性骶骨切除后骨盆力学特性变化的三维有限元分析

An investigation of the biomechanical implications of sacrectomy using finite element models

目的研究正常骨盆和选择性切除骶骨后骨盆力学特性变化。方法应用CT影像资料建立正常骨盆和选择性切除骶骨后骨盆的三维有限元模型,计算分析生理载荷下骶骨及整个骨盆的应力分布和应力传导变化。结果骶骨应力主要分布在S1。经S3孔上缘、经S2孔下缘、经S2孔上缘切除时骨盆应力分布和传导变化很小。经S1孔下缘切除时骶髂关节局部应力值明显增加为2.1倍,经S1孔上缘时应力值急剧增加达4.3倍。结论骶骨的主要应力传导结构位于S1,骶骨切除S1孔平面以下对骶骨应力传导影响较小,切除达S1孔平面以上将严重损害骨盆的稳定性,承重能力的降低可能导致骨折的危险。

Objective To investigate the biomechanical implications of the sacrectomy by finite element modeling and analysis. Methods By using 3-D finite element models based on CT image data of human pelvis, the main stress value and stress distribution were analyzed when the superior surface of the sacrum was loaded by physiological static stress. Results Stress was mainly distributed above S1. The pelvic stress and strain did not increase significantly when resection involved the S2 and S3 foramina. The average stress increased 4.3 times with transection cephalad to the S1 foramina and 2. 1 times with transection caudal to the S1 foramina on the sacral side of the joint by FEM. Conclusions After excision of sacrum cephalad to the foramina of S1, the stress transduction within sacrum and pelvis is little affected, while excision caudal to the foramina of S1 , the stability of the pelvis is damaged unbearably, the decreased weight bearing ability of sacrum would result in fracture.