Customized spinal implants fabricated by additive manufacturing have been increasingly used clinically to restore the physiological functions. However, the mechanisms and methods about the design for the spinal implants are not clear, especially for the reconstruction of multi-segment vertebral. This study aims to develop a novel multi-objective optimization methodology based on various normal spinal activities, to design the artificial vertebral implant (AVI) with lightweight, high-strength and high-stability. The biomechanical performance for two types of AVI was analyzed and compared under different loading conditions by finite element method. These implants were manufactured via selective laser melting technology and evaluated via compressive testing. Results showed the maximum Mises stress of the optimized implant under various load cases were about 41.5% of that of the trussed implant, and below fatigue strength of 3D printed titanium materials. The optimized implant was about 2 times to trussed implant in term of the maximum compression load and compression stiffness to per unit mass, which indicated the optimized implant can meet the safety requirement. Finally, the optimized implant has been used in clinical practice and good short-term clinical outcomes were achieved. Therefore, the novel developed method provides a favorable guarantee for the design of 3D printed multi-segment artificial vertebral implants.

通过增材制造制造的定制脊柱植入物在临床上越来越多地用于恢复生理功能。然而，脊柱植入物的设计机制和方法尚不清楚，尤其是多节段椎体的重建。本研究旨在开发一种基于各种正常脊柱活动的新型多目标优化方法，以设计具有轻质、高强度和高稳定性的人工椎骨植入物（AVI）。采用有限元方法对两种类型的AVI在不同载荷条件下的生物力学性能进行了分析比较。这些植入物是通过选择性激光熔化技术制造的，并通过压缩测试进行评估。结果表明，优化后的种植体在各种负载情况下的最大 Mises 应力约为桁架式种植体的 41.5%，低于 3D 打印钛材料的疲劳强度。优化后的种植体每单位质量的最大压缩载荷和压缩刚度约为桁架式种植体的2倍，表明优化后的种植体能够满足安全性要求。最后，优化后的种植体已应用于临床，取得了良好的短期临床效果。因此，新开发的方法为3D打印多节段人工椎骨植入物的设计提供了有利的保证。优化后的种植体每单位质量的最大压缩载荷和压缩刚度约为桁架式种植体的2倍，表明优化后的种植体能够满足安全性要求。最后，优化后的种植体已应用于临床，取得了良好的短期临床效果。因此，新开发的方法为3D打印多节段人工椎骨植入物的设计提供了有利的保证。优化后的种植体每单位质量的最大压缩载荷和压缩刚度约为桁架式种植体的2倍，表明优化后的种植体能够满足安全性要求。最后，优化后的种植体已应用于临床，取得了良好的短期临床效果。因此，新开发的方法为3D打印多节段人工椎骨植入物的设计提供了有利的保证。