Prot M, Saletti D, Pattofatto S, Bousson V, Laporte S
LBM/Institut de Biomécanique Humaine Georges Charpak, 151 Boulevard de l׳Hôpital, 75013 Paris, France.
LBM/Institut de Biomécanique Humaine Georges Charpak, 151 Boulevard de l׳Hôpital, 75013 Paris, France; Univ. Grenoble Alpes, 3SR, F-38000 Grenoble, France.
J Biomech. 2015 Feb 5;48(3):498-503. doi: 10.1016/j.jbiomech.2014.12.002. Epub 2014 Dec 18.
Previous studies show that in vivo assessment of fracture risk can be achieved by identifying the relationships between microarchitecture description from clinical imaging and mechanical properties. This study demonstrates that results obtained at low strain rates can be extrapolated to loadings with an order of magnitude similar to trauma such as car crashes. Cancellous bovine bone specimens were compressed under dynamic loadings (with and without confinement) and the mechanical response properties were identified, such as Young׳s modulus, ultimate stress, ultimate strain, and ultimate strain energy. Specimens were previously scanned with pQCT, and architectural and structural microstructure properties were identified, such as parameters of geometry, topology, connectivity and anisotropy. The usefulness of micro-architecture description studied was in agreement with statistics laws. Finally, the differences between dynamic confined and non-confined tests were assessed by the bone marrow influence and the cancellous bone response to different boundary conditions. Results indicate that architectural parameters, such as the bone volume fraction (BV/TV), are as strong determinants of mechanical response parameters as ultimate stress at high strain rates (p-value<0.001). This study reveals that cancellous bone response at high strain rates, under different boundary conditions, can be predicted from the architectural parameters, and that these relations with mechanical properties can be used to make fracture risk prediction at a determined magnitude.
先前的研究表明，通过确定临床成像中的微观结构描述与力学性能之间的关系，可以实现骨折风险的体内评估。本研究表明，在低应变率下获得的结果可以外推到与车祸等创伤相似量级的载荷情况。对松质牛骨标本在动态载荷下（有和没有约束）进行压缩，并确定其力学响应特性，如杨氏模量、极限应力、极限应变和极限应变能。标本之前用pQCT进行过扫描，并确定了其结构和微观结构特性，如几何、拓扑、连通性和各向异性参数。所研究的微观结构描述的有用性与统计规律相符。最后，通过骨髓影响和松质骨对不同边界条件的响应，评估了动态约束试验和非约束试验之间的差异。结果表明，在高应变率下，诸如骨体积分数（BV/TV）等结构参数与极限应力一样，都是力学响应参数的强大决定因素（p值<0.001）。本研究表明，在不同边界条件下，高应变率下松质骨的响应可以根据结构参数进行预测，并且这些与力学性能的关系可用于在确定量级上进行骨折风险预测。
