骨盆定制假体的设计及有限元分析

Design and finite element analysis of customized pelvic prosthesis

目的:介绍骨盆定制假体的设计,利用有限元分析方法评价骨盆肿瘤定制假体在3种不同工况下的生物力学性能。方法:利用CAD软件设计1例骨盆肿瘤患者重建所需的钛合金材质假体,用有限元法分析检查和评估该定制假体在静态和缓慢步态工况下的强度和刚度值。结果:有限元分析结果表明,3种工况下骨盆的最大Von Mises应力分别为39.0、202.8、42.4 MPa;最大位移分别为0.199、0.766、0.847 mm。假体中的最大Von Mises应力分别为62.3、318、468 MPa。骨盆和假体中的最大Von Mises应力都远低于相应材料的屈服强度。结论:该研究可以根据患者情况对定制假体的形状和尺寸做精确设计,通过有限元法强度计算可以降低骨骼应力水平和骨折风险,延长假体的使用寿命,保证了患者术后正常步态下的安全性和稳定性。

Objective:To introduce the design of customized pelvic prosthesis,to evaluate the biomechanical property under three load conditions of customized pelvic prosthesis under three load cinditions.Methods:A titanium alloy prosthesis for reconstruction of pelvic tumors was designed by CAD software.The strength and stiffness of the custom prosthesis under static and slow gait conditions were analyzed and evaluated by finite element method.Results:The results of the finite element analysis suggested that the maximum von Mises stress in the pelvic under three load conditions were 39.0,202.8 and 42.4 MPa;the maximum displacement were 0.199,0.766 and 0.847 mm.The maximum von Mises stress in the prosthesis under three load conditions were 62.3,318 and 468 MPa.The maximum Von Mises stress in the Ti-alloy prosthesis and pelvic was far smaller than the yield strength of Ti-alloy.Conclusion:The study can design the size and shape of prosthesis accurately according to patient’s condition.The finite element method can reduce the bone stress level and fracture risk,prolong the service life of prostheses,and ensure the safety and stability of the postoperative patients under normal gait.