Institute for Biomechanics, BG Unfallklinik Murnau, Prof. Küntscher Str. 8, 82418 Murnau, Germany; Institute for Biomechanics, Paracelsus Medical University Salzburg, Strubergasse 21, 5020 Salzburg, Austria.
Institute for Biomechanics, BG Unfallklinik Murnau, Prof. Küntscher Str. 8, 82418 Murnau, Germany; Institute for Biomechanics, Paracelsus Medical University Salzburg, Strubergasse 21, 5020 Salzburg, Austria.
Med Eng Phys. 2024 Aug;130:104210. doi: 10.1016/j.medengphy.2024.104210. Epub 2024 Jul 17.
In addition to human donor bones, bone models made of synthetic materials are the gold standard substitutes for biomechanical testing of osteosyntheses. However, commercially available artificial bone models are not able to adequately reproduce the mechanical properties of human bone, especially not human osteoporotic bone. To overcome this issue, new types of polyurethane-based synthetic osteoporotic bone models have been developed. Its base materials for the cancellous bone portion and for the cortical portion have already been morphologically and mechanically validated against human bone. Thus, the aim of this study was to combine the two validated base materials for the two bone components to produce femur models with real human geometry, one with a hollow intramedullary canal and one with an intramedullary canal filled with synthetic cancellous bone, and mechanically validate them in comparison to fresh frozen human bone. These custom-made synthetic bone models were fabricated from a computer-tomography data set in a 2-step casting process to achieve not only the real geometry but also realistic cortical thicknesses of the femur. The synthetic bones were tested for axial compression, four-point bending in two planes, and torsion and validated against human osteoporotic bone. The results showed that the mechanical properties of the polyurethane-based synthetic bone models with hollow intramedullary canals are in the range of those of the human osteoporotic femur. Both, the femur models with the hollow and spongy-bone-filled intramedullary canal, showed no substantial differences in bending stiffness and axial compression stiffness compared to human osteoporotic bone. Torsional stiffnesses were slightly higher but within the range of human osteoporotic femurs. Concluding, this study shows that the innovative polyurethane-based femur models are comparable to human bones in terms of bending, axial compression, and torsional stiffness.
除了人类捐赠的骨头外，由合成材料制成的骨模型是骨合成物生物力学测试的黄金标准替代品。然而，市售的人工骨模型无法充分复制人类骨的机械性能，尤其是骨质疏松症患者的骨头。为了解决这个问题，已经开发出了新型基于聚氨酯的合成骨质疏松症骨模型。其松质骨部分和皮质骨部分的基础材料已经在形态和机械性能上与人类骨骼进行了验证。因此，本研究的目的是将两种已验证的基础材料结合起来，制造具有真实人体几何形状的股骨模型，一种带有中空髓腔，另一种带有填充合成松质骨的髓腔，并对其进行机械验证，以与新鲜冷冻的人类骨骼进行比较。这些定制的合成骨模型是从计算机断层扫描数据集在两步铸造过程中制造的，不仅实现了真实的几何形状，还实现了股骨的真实皮质厚度。对合成骨进行了轴向压缩、两个平面的四点弯曲和扭转测试，并与骨质疏松症患者的骨骼进行了验证。结果表明，具有中空髓腔的基于聚氨酯的合成骨模型的机械性能在骨质疏松症患者的人类股骨范围内。具有中空和填充海绵骨髓腔的股骨模型在弯曲刚度和轴向压缩刚度方面与骨质疏松症患者的骨骼没有明显差异。扭转刚度略高，但在骨质疏松症患者的股骨范围内。总之，本研究表明，这种创新的基于聚氨酯的股骨模型在弯曲、轴向压缩和扭转刚度方面与人类骨骼相当。
