3D打印钛合金个性化骨盆假体静态和步态有限元分析

目的 通过有限元分析方法评价3D打印个性化钛合金骨盆假体在站立位静态和步态下的生物力学性能。方法 选取3例不同类型的骨盆肿瘤患者，拟行半骨盆切除人工半骨盆置换术。术前行CT和MRI检查，设计相应的个性化钛合金人工半骨盆假体，利用三维重建技术进行骨盆重建，并与个性化骨盆假体装配。通过AnyBody软件建立患者的人体骨肌系统模型并进行步态动力学分析。导入ABAQUS软件，得到3例重建骨盆模型在静态和步态条件下的应力分布和应力集中区域。 结果 在静态和步态条件下，3例3D打印钛合金骨盆假体的最大应力均小于钛合金的屈服强度，重建骨盆的骨盆环能够满足应力传导规律，患者术后恢复正常。结论 3D打印个性化钛合金骨盆假体对恢复骨盆环的应力传导效果良好，其有效性和稳定性能够满足人体生物力学要求，分析结果可为临床医生和假体设计人员提供参考。
Objective To evaluate the biomechanical properties of 3D printed individualized titanium alloy pelvic prosthesis in static and gait states by the method of finite element analysis. Methods Three patients with different types of pelvic tumors were treated by hemi-pelvic arthroplasty with resection of hemi-pelvis. CT and MRI were performed before the surgery, and the corresponding individualized titanium alloy pelvic prostheses were designed. The pelvic models were reconstructed with 3D reconstruction technique, and then assembled with the individualized pelvic prostheses. The human skeletal muscle model was established by AnyBody software to perform gait dynamics analysis. The stress distribution and stress concentration areas of 3 reconstructed pelvic models in static and gait states were obtained by ABAQUS. Results Under both static and gait conditions, the maximum stress of the 3 pelvic prostheses was smaller than the yield strength of the titanium alloy. The pelvic ring of the reconstructed pelvis could meet the rule of stress conduction. The patients’ daily life returned to normal condition after the surgery. Conclusions The effect of 3D prosthetic titanium prosthesis on recovery of pelvic ring is satisfactory, and its effectiveness and stability can meet the requirement of human biomechanics. The analytic results can provide references for clinicians and prosthesis designers.