Large cortical bone pores in the tibia are associated with proximal femur strength
Large cortical bone pores in the tibia are associated with proximal femur strength
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DOI：
10.1371/journal.pone.0215405
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发表时间：
2019-04-17
期刊：
影响因子：
3.7
通讯作者：
Raum, Kay
中科院分区：
文献类型：
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作者：
Iori, Gianluca;Schneider, Johannes;Raum, Kay
皮质骨结构和密度的改变与脆性骨折有关，可以在人体胫骨进行活体评估。老年女性的骨重建缺陷最近被认为与皮质毛孔大小增加有关。在这项体外研究中，我们描述了19个来自人类捐献者(年龄69-94岁)的胫骨的皮质微结构，以解决这是否能反映股骨近端机械能力的损害，即骨质疏松的一个主要骨折部位。扫描声学显微镜(12µm像素大小)提供左侧胫骨的参考微结构测量，而该位置的骨vBMD是通过微CT(MicroCT)获得的。采用双能X线骨密度仪(DXA)测量左、右股骨颈的骨密度(aBMD，Neck)，而基于高分辨率外周定量CT的均匀化非线性有限元模型提供了单腿站立和侧向跌落载荷下的髋关节刚度和强度。髋关节力量与BMD(颈部)(r=0.74~0.78)、胫骨皮质厚度(r=0.81)、同腿胫骨横断面几何尺寸(r=0.48~0.73)相关。胫骨vBMD仅在站立负荷时与髋关节力量相关(r=0.59~0.65)。胫骨的皮质孔隙度(Ct.Po)与任何股骨参数无关。然而，在站立(r=-0.61)和下落(r=0.48)条件下，大孔(直径>；100微米)所占比例与髋关节力量有关。当加上BMD(颈部)时，大毛孔的流行可以解释高达17%的股骨极限力。总而言之，胫骨的微结构特征反映了髋关节的力量和股骨的DXA，但这些特性是否可以在体内测量还有待测试。
Alterations of structure and density of cortical bone are associated with fragility fractures and can be assessed in vivo in humans at the tibia. Bone remodeling deficits in aging women have been recently linked to an increase in size of cortical pores. In this ex vivo study, we characterized the cortical microarchitecture of 19 tibiae from human donors (aged 69 to 94 years) to address, whether this can reflect impairments of the mechanical competence of the proximal femur, i.e., a major fracture site in osteoporosis. Scanning acoustic microscopy (12 mu m pixel size) provided reference microstructural measurements at the left tibia, while the bone vBMD at this site was obtained using microcomputed tomography (microCT). The areal bone mineral density of both left and right femoral necks (aBMD(neck)) was measured by dual-energy X-ray absorptiometry (DXA), while homogenized nonlinear finite element models based on high-resolution peripheral quantitative computed tomography provided hip stiffness and strength for one-legged standing and sideways falling loads. Hip strength was associated with aBMD(neck) (r = 0.74 to 0.78), with tibial cortical thickness (r = 0.81) and with measurements of the tibial cross-sectional geometry (r = 0.48 to 0.73) of the same leg. Tibial vBMD was associated with hip strength only for standing loads (r = 0.59 to 0.65). Cortical porosity (Ct.Po) of the tibia was not associated with any of the femoral parameters. However, the proportion of Ct.Po attributable to large pores (diameter > 100 mu m) was associated with hip strength in both standing (r = -0.61) and falling (r = 0.48) conditions. When added to aBMD(neck), the prevalence of large pores could explain up to 17% of the femur ultimate force. In conclusion, microstructural characteristics of the tibia reflect hip strength as well as femoral DXA, but it remains to be tested whether such properties can be measured in vivo.