骶骨肿瘤切除术后骨盆三维有限元模型的建立及相关应力分析

Establishment of pelvic three-dimensional finite element model and its stress analysis after-sacrum tumar excision

目的研究骶骨肿瘤切除术后骨盆三维有限元模型的建立及相关应力分析。方法利用三维有限元分析软件ANSYS,建立正常骨盆模型和模拟骶骨肿瘤切除术后骨盆模型,并根据坐位承重情况,对比研究相关应力分布。结果成功建立正常骨盆模型和模拟骶骨肿瘤切除术后骨盆模型,并对其在坐位时承重情况进行加载分析,证明:(1) 完整骨盆受到外力后,力的传导沿腰椎→骶骨→双侧骶髂关节面→髂骨→坐骨支的传导途径,力的分布比较分散, 相应节点上受到的压强平均,最高压强局限;而骶骨肿瘤切除术后骨盆模型在受到外力后,由于丧失了大部分的骶骨,使得力的传导受限。(2)去掉骶骨后,骶髂关节周围和坐骨支处的节点受到的压强超过完整骨盆,即骨盆的稳定性降低,导致骨盆完整性的改变。结论建立骶骨肿瘤切除术后三维有限元模型并与完整骨盆模型对比,说明其稳定性发生变化。

Objective To study three-dimensional finite element model of pelvis and make its stress analysis aftersacrum tumar excision. Methods By using theanalysis software-＂ansys＂, we have established two models： the whole pelvic model and the model after-sacrum tumar excision, and compare the stresses getting from the models. Results After establishing the two models and loading on them respectively, the results were got as following：（1） In the whole pelvic model, the forcestransmittedalong theroute： lumbar→sacrum→sacroiliac joint→ilium→ischial. For each of the node, the force distribution is symmetrical with limited intensity of pressure . While in the model with sacrum tumar excision, the transmission is affected. （2） In the SF model, the forces of nodes in the sacroiliac joint and ischium are larger than that in the same nodes in the whole pelvic model,which may cause the stability of pelvic is descend and the opportunity of loss of pelvic integrality is ascend. Conclusion By establishment of pelvic three-dimensional finite element model after-excision of sacrum tumar and its stress analysis comparing with the whole pelvic model, it is proved that its stability has been changed.