The additive manufacturing techniques (AM) are able to realize three-dimensional trabecular structures that mimic the trabecular structure of the bone. An in vivo study in sheep was carried out with the aim of assessing the bone response and the trend of osteointegration of a randomized trabecular titanium structure produced by the AM technique. In 6 sheep were implanted 84 specimens with a trabecular titanium structure (4 implants in the femur distal epiphysis; 4 implants in the tibial plate; 6 implants in the tibial shaft). Sheep were sacrificed at 3 postoperative time-points: 6 weeks, 10 weeks, 14 weeks. Histomorphometric analysis was performed for the evaluation of Bone Implant Contact, and Bone Ingrowth. A standard push-out test was used to analyze the mechanical characteristics of the bone-implant interface. The histomorphometric data and biomechanical tests showed a fast osseointegration of the specimens both in the cancellous and in the cortical bone. The quantitative analysis of osseointegration data in cancellous bone showed the percentage of the surface of the implant in direct contact with the regenerated bone matrix significantly improved from 28% at 6 weeks to 54% at 14 weeks. An early osseointegration occurred in cortical bone showing that 75% of surface of implant was in direct contact with regenerated bone after 6 weeks; this value increased to 85% after 14 weeks. Mechanical tests revealed an early improvement of mean peak load of implants at 10 weeks (4486 N ± 528 N) compared to values at 6 weeks (2516 N ± 910 N) confirming the high rate of progression of osseointegration in the cortical bone. The non-mineralized matrix followed an increasing process of mineralization almost completely after 14 weeks. The results of this study have showed a rapid osseointegration and excellent biocompatibility for a randomized trabecular titanium structure that should be confirmed by clinical investigations.

中文翻译：

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通过增材制造技术获得的随机性小梁钛结构的体内骨整合。

增材制造技术（AM）能够实现模拟骨骼的小梁结构的三维小梁结构。为了评估由AM技术生产的随机小梁钛结构的骨骼反应和骨整合趋势，在绵羊中进行了一项体内研究。在6只绵羊中植入了84个具有小梁钛结构的标本（股骨远端骨physi中有4个植入物；胫骨板中有4个植入物；胫骨干中有6个植入物）。在3个术后时间点处死绵羊：6周，10周，14周。进行组织形态计量学分析，以评估骨植入物接触和骨向内生长。使用标准推出测试来分析骨-植入物界面的机械特性。组织形态计量学数据和生物力学测试表明，在松质骨和皮质骨中，标本均快速骨整合。松质骨中骨整合数据的定量分析表明，与再生骨基质直接接触的植入物表面的百分比从6周时的28％显着提高到14周时的54％。皮质骨中发生了早期骨整合，显示6周后75％的植入物表面与再生骨直接接触。14周后，该值增加到85％。机械测试显示，与6周（2516 N±910 N）时的值相比，第10周（4486 N±528 N）的植入物的平均峰值负荷有较早的改善，证实了皮质骨中骨整合的高进展率。14周后，未矿化的基质几乎完全遵循矿化过程。这项研究的结果表明，对于随机的小梁钛结构，骨融合迅速且具有良好的生物相容性，应通过临床研究予以证实。