Department of Mechanical Engineering, University of Massachusetts Dartmouth, 285 Old Westport Road, Dartmouth, MA, 02747, USA.
Department of Industrial and Manufacturing Engineering, Kettering University, 1700 University Ave, Flint, MI, 48504, USA.
Med Biol Eng Comput. 2024 Jul;62(7):2005-2017. doi: 10.1007/s11517-024-03038-7. Epub 2024 Mar 3.
Developing patient-specific implants has an increasing interest in the application of emerging additive manufacturing (AM) technologies. On the other hand, despite advances in total knee replacement (TKR), studies suggest that up to 20% of patients with elective TKR are dissatisfied with the outcome. By creating 3D objects from digital models, AM enables the production of patient-specific implants with complex geometries, such as those required for knee replacements. Previous studies have highlighted concerns regarding the risk of residual stresses and shape distortions in AM parts, which could lead to structural failure or other complications. This article presents a computational framework that uses CT images to create patient-specific finite element models for optimizing AM knee replacements. The workflow includes image processing in the open-source software 3DSlicer and MeshLab and AM process simulations in the commercial platform 3DEXPERIENCE. The approach is demonstrated on a distal femur replacement for a 50-year-old male patient from the open-access Natural Knee Data. The results show that build orientations have a significant impact on both shape distortions and residual stresses. Support structures have a marginal effect on residual stresses but strongly influence shape distortions, whereas conical support exhibits a maximum distortion of 18.5 mm. Future research can explore how these factors affect the functionality of AM knee replacements under in-service loading.
在新兴增材制造（AM）技术的应用中，开发针对患者个体的植入物越来越受到关注。另一方面，尽管全膝关节置换术（TKR）取得了进展，但研究表明，高达 20%的接受选择性 TKR 的患者对治疗结果不满意。通过从数字模型创建 3D 对象，AM 能够生产具有复杂几何形状的患者特定植入物，例如膝关节置换所需的那些。先前的研究强调了对 AM 零件中残余应力和形状变形风险的关注，这可能导致结构失效或其他并发症。本文提出了一种计算框架，该框架使用 CT 图像为优化 AM 膝关节置换创建针对患者个体的有限元模型。该工作流程包括在开源软件 3DSlicer 和 MeshLab 中进行图像处理，以及在商业平台 3DEXPERIENCE 中进行 AM 工艺模拟。该方法在来自开放获取的 Natural Knee Data 的一名 50 岁男性患者的远端股骨置换物上进行了演示。结果表明，构建方向对形状变形和残余应力都有显著影响。支撑结构对残余应力的影响较小，但对形状变形的影响较大，而锥形支撑的最大变形为 18.5 毫米。未来的研究可以探讨这些因素如何在实际负载下影响 AM 膝关节置换的功能。
