Trabecular bone structure is crucial to normal mechanical behavior of bones. Studies have shown that osteoporosis negatively affects trabecular bone structure, mainly by reducing bone volume fraction (BV/TV) and thus increasing fracture risk. One major limitation in assessing and quantifying the effect of this structural deterioration is that no two trabecular structures are identical. Thus, when we compare a group of healthy bones against a different group of bones that experienced resorption (i.e. decreased BV/TV) we only discover an “average” mechanical effect. It is impossible to quantify the mechanical effect of individual structural deterioration for each sample, simply because we never have the same sample in both states (intact and deteriorated structure). 3D printing is a new technology that can assist in overcoming this issue. Here we report a preliminary study that compares a healthy 3D printed trabecular bone model with the same model after bone resorption was simulated. Since the deteriorated structural bone model is derived from the healthy one, it is possible to directly estimate (percentage wise) the decrease of tissue stiffness and strength as a result of bone resorption for this specific structure. Our results demonstrate that a relatively small decrease in BV/TV (about 8%) leads to a dramatic decrease in structural strength (24%) and structural stiffness (17%), (P < 0.01). Structural strength decreased from an average of 9.14 ± 2.85 MPa to 6.97 ± 2.44 MPa, while structural stiffness decreased from an average of 282.5 ± 63.4 N/mm to 233.8 ± 51.2 N/mm. This study demonstrates that 3D printing is a novel and valuable tool for quantifying the effect of structural deterioration on the mechanical properties of trabecular bone. In the future, this approach may help us attain better personal fracture risk assessments by CT scanning, 3D printing and mechanically testing individual bone replicas from patients suffering excessive bone resorption.

骨小梁结构对于骨骼的正常机械行为至关重要。研究表明，骨质疏松症会对骨小梁结构产生负面影响，主要是通过降低骨体积分数（BV/TV），从而增加骨折风险。评估和量化这种结构恶化的影响的一个主要限制是没有两个小梁结构是相同的。因此，当我们将一组健康骨骼与另一组经历吸收（即 BV/TV 降低）的骨骼进行比较时，我们只发现“平均”机械效应。量化每个样本的个体结构恶化的机械效应是不可能的，因为我们从来没有处于两种状态（完整和恶化的结构）的相同样本。3D打印是一项可以帮助克服这个问题的新技术。在这里，我们报告了一项初步研究，该研究将健康的 3D 打印骨小梁模型与模拟骨吸收后的相同模型进行了比较。由于恶化的结构骨模型源自健康的结构骨模型，因此可以直接估计（百分比）由于该特定结构的骨吸收而导致的组织刚度和强度的降低。我们的结果表明，BV/TV 相对较小的下降（约 8%）会导致结构强度（24%）和结构刚度（17%）急剧下降（P < 0.01）。结构强度从平均 9.14 ± 2.85 MPa 下降到 6.97 ± 2.44 MPa，而结构刚度从平均 282.5 ± 63.4 N/mm 下降到 233.8 ± 51.2 N/mm。这项研究表明，3D 打印是一种新颖且有价值的工具，可用于量化结构退化对骨小梁机械性能的影响。未来，这种方法可能会帮助我们通过 CT 扫描、3D 打印和机械测试来自遭受过度骨吸收的患者的个体骨复制品来获得更好的个人骨折风险评估。