目前,关节置换术中骨缺损的治疗是临床实践中的挑战。尽管如此,市售的骨科支架对大型骨缺损的治疗效果有限,特别是对于大量和不规则的缺陷。增材制造多孔钽,特别是,已成为这种支架的有前途的材料,并因其出色的生物相容性而广泛用于骨科,骨诱导,和机械性能。多孔钽在个性化快速制造方面也表现出独特的优势,这允许以低成本和高效率创建具有用于临床应用的复杂几何形状的定制支架。然而,关于增材制造多孔钽的孔结构对骨再生的影响的研究很少。在这项研究中,我们小组通过激光粉末床融合(LPBF)设计并制造了一批孔径为250μm(Ta250)的精密多孔钽支架,450μm(Ta450),650μm(Ta650),和850μm(Ta850)。然后我们进行了一系列体外实验,观察到所有四组都显示出良好的生物相容性。特别是,Ta450表现出最好的成骨性能。之后,我们的团队使用大鼠骨缺损模型来确定体内成骨作用。基于显微计算机断层扫描和组织学,我们确定Ta450表现出最佳的骨向内生长性能。随后,绵羊股骨和髋关节缺损模型用于进一步证实Ta450支架的成骨作用。最后,我们通过Ta450支架的临床应用(7例等待翻修全髋关节置换术的患者)验证了上述体外和体内结果。临床结果证实,直到12个月的随访,Ta450具有令人满意的临床结果。总之,我们的发现表明450μm是多孔钽支架的合适孔径。本研究可能为治疗大量,无法挽回,和关节成形术中的长期骨缺损。
Currently, the treatment of bone defects in arthroplasty is a challenge in clinical practice. Nonetheless, commercially available orthopaedic scaffolds have shown limited therapeutic effects for large bone defects, especially for massiveand irregular defects. Additively manufactured porous tantalum, in particular, has emerged as a promising material for such scaffolds and is widely used in orthopaedics for its exceptional biocompatibility, osteoinduction, and mechanical properties. Porous tantalum has also exhibited unique advantages in personalised rapid manufacturing, which allows for the creation of customised scaffolds with complex geometric shapes for clinical applications at a low cost and high efficiency. However, studies on the effect of the pore structure of additively manufactured porous tantalum on bone regeneration have been rare. In this study, our group designed and fabricated a batch of precision porous tantalum scaffolds via laser powder bed fusion (LPBF) with pore sizes of 250 μm (Ta 250), 450 μm (Ta 450), 650 μm (Ta 650), and 850 μm (Ta 850). We then performed a series of in vitro experiments and observed that all four groups showed good biocompatibility. In particular, Ta 450 demonstrated the best osteogenic performance. Afterwards, our team used a rat bone defect model to determine the in vivo osteogenic effects. Based on micro-computed tomography and histology, we identified that Ta 450 exhibited the best bone ingrowth performance. Subsequently, sheep femur and hip defect models were used to further confirm the osteogenic effects of Ta 450 scaffolds. Finally, we verified the aforementioned in vitro and in vivo results via clinical application (seven patients waiting for revision total hip arthroplasty) of the Ta 450 scaffold. The clinical results confirmed that Ta 450 had satisfactory clinical outcomes up to the 12-month follow-up. In summary, our findings indicate that 450 μm is the suitable pore size for porous tantalum scaffolds. This study may provide a new therapeutic strategy for the treatment of massive, irreparable, and protracted bone defects in arthroplasty.