Large bone defects remain a clinical challenge because they do not heal spontaneously. 3-D printed scaffolds are a promising treatment option for such critical defects. Recent scaffold design strategies have made use of computer modelling techniques to optimize scaffold design. In particular, scaffold geometries have been optimized to avoid mechanical failure and recently also to provide a distinct mechanical stimulation to cells within the scaffold pores. This way, mechanical strain levels are optimized to favour the bone tissue formation. However, bone regeneration is a highly dynamic process where the mechanical conditions immediately after surgery might not ensure optimal regeneration throughout healing. Here, we investigated in silico whether scaffolds presenting optimal mechanical conditions for bone regeneration immediately after surgery also present an optimal design for the full regeneration process. A computer framework, combining an automatic parametric scaffold design generation with a mechano-biological bone regeneration model, was developed to predict the level of regenerated bone volume for a large range of scaffold designs and to compare it with the scaffold pore volume fraction under favourable mechanical stimuli immediately after surgery. We found that many scaffold designs could be considered as highly beneficial for bone healing immediately after surgery; however, most of them did not show optimal bone formation in later regenerative phases. This study allowed to gain a more thorough understanding of the effect of scaffold geometry changes on bone regeneration and how to maximize regenerated bone volume in the long term.

大骨缺损仍然是一个临床挑战，因为它们不会自发愈合。3-D 打印支架是治疗此类严重缺陷的有希望的选择。最近的脚手架设计策略已经利用计算机建模技术来优化脚手架设计。特别是，支架的几何形状已经过优化，以避免机械故障，最近还为支架孔内的细胞提供了独特的机械刺激。这样，机械应变水平得到优化，有利于骨组织的形成。然而，骨再生是一个高度动态的过程，手术后立即的机械条件可能无法确保整个愈合过程中的最佳再生。在这里，我们在 silico 中进行了调查支架是否在手术后立即为骨再生提供最佳机械条件也为完全再生过程提供最佳设计。开发了一种计算机框架，将自动参数化支架设计生成与机械生物骨再生模型相结合，以预测大量支架设计的再生骨体积水平，并将其与有利机械条件下的支架孔体积分数进行比较手术后立即刺激。我们发现许多支架设计可以被认为对手术后的骨愈合非常有益。然而，它们中的大多数在再生后期没有表现出最佳的骨形成。