3D打印技术应用于胸骨缺损修复的可行性研究

摘要

目的 验证3D打印技术制作个体化钛合金胸骨假体的力学性能和应力分布,探讨其在修复胸骨缺损中应用的可行性.方法 通过胸部CT三维重建数据构建骨性胸廓模型,应用计算机辅助设计技术及镜像技术,设计目标假体的三维数据,并通过三维有限元对假体进行应力分析;之后采用钛合金粉末打印出与缺损骨质完全匹配的假体,进行强度测试;最后进行手术植入完成胸骨缺损的修复.结果 3D打印的钛合金假体的屈服强度为(950±14) MPa,极限强度为(1005±26) MPa.三维有限元分析结果显示,胸骨假体等效应力分布均匀.假体能够精确重塑原有胸廓的几何形态和解剖外形,随访半年植入物与周围骨性结构固定牢靠,与周围组织相容性良好,无排异反应发生.结论 通过计算机辅助设计和3D打印技术能够制作出高精度个性化钛合金胸骨假体,材料性能满足外科临床植入物的标准,对胸壁重建塑形效果良好,手术操作简便,此方法是胸骨大块缺损修复的可靠技术保证.%Objective To study the mechanical properties and stress distribution of custom design and printed sternum prosthesis in reconstructing large sternum defects of chest wall following en-bloc surgery,demonstrate its feasibility.Methods 3D model of the bony defect is generated after the acquisition of helical CT data.A customized implant is designed using Computer Aided Design(CAD) and mirror technology and later fabricated using titanium alloy powder.The end result product are then fixed onto patient during surgery.Results The yield strength of the titanium alloy implants were(950 ± 14)MPa,and the ultimate tensile strength were (1005 ± 26) MPa.Three dimensional finite element analysis results showed an evenly stress distribution of the implant.The reconstruction quality and contour of the repaired chest wall was satisfactory.No rejection occurred during the 6month follow-up.Conclusion Chest reconstruction with customized titanium alloy sternum prosthesis is a reliable technique for the repair of the bony defect.