Large bone defects are a challenge for orthopedic surgery. Natural (bone grafts) and synthetic biomaterials have been proposed but several problems arise such as biomechanical resistance or viral/bacterial safety. The use of metallic foams could be a solution to improve mechanical resistance and promote osseointegration of large porous metal devices. Titanium cylinders have been prepared by additive manufacturing (3D printing/rapid prototyping) with a geometric or trabecular microarchitecture. They were implanted in the femoral condyles of aged ewes; the animals were left in stabling for 90 and 270 days. A double calcein labeling was done before sacrifice; bones were analyzed by histomorphometry. Neither bone volume, bone/titanium interface nor mineralization rate were influenced by the cylinder’s microarchitecture; the morphometric parameters did not significantly increase over time. Bone anchoring occurred on the margins of the cylinders and some trabeculae extended in the core of the cylinders but the amount of bone inside the cylinders remained low. The rigid titanium cylinders preserved bone cells from strains in the core of the cylinders. Additive manufacturing is an interesting tool to prepare 3D metallic scaffolds, but microarchitecture does not seem as crucial as expected and anchoring seems limited to the first millimeters of the graft.

中文翻译：

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通过增材制造获得的钛圆柱体的微结构不会影响绵羊的骨整合

大骨缺损对骨科手术来说是一个挑战。天然（骨移植）和合成生物材料已被提出，但出现了一些问题，例如生物力学阻力或病毒/细菌安全性。使用金属泡沫可能是提高机械阻力并促进大型多孔金属装置骨整合的解决方案。钛圆柱体通过增材制造（3D 打印/快速原型制作）制备而成，具有几何或小梁微结构。它们被植入老年母羊的股骨髁中；这些动物被留在马厩里90天和270天。处死前进行双钙黄绿素标记；通过组织形态计量学分析骨骼。骨体积、骨/钛界面和矿化率均不受圆柱体微结构的影响；形态测量参数并没有随着时间的推移而显着增加。骨锚定发生在圆柱体的边缘，一些小梁在圆柱体的核心延伸，但圆柱体内的骨量仍然很低。刚性钛圆柱体可以保护骨细胞免受圆柱体核心应变的影响。增材制造是制备 3D 金属支架的一种有趣的工具，但微结构似乎并不像预期的那么重要，而且锚定似乎仅限于移植物的最初几毫米。