Carrieroa A, Pereirab A F, Wilson A J, Castagno S, Javaheri B, Pitsillides A A, Marenzana M, Shefelbine S J
Department of Biomedical Engineering, The City College of New York, New York, NY, USA.
Department of Bioengineering, Imperial College London, UK.
Bone Rep. 2018 Jun;8:72-80. doi: 10.1016/j.bonr.2018.02.003. Epub 2018 Feb 16.
Bone is a dynamic tissue and adapts its architecture in response to biological and mechanical factors. Here we investigate how cortical bone formation is spatially controlled by the local mechanical environment in the murine tibia axial loading model (C57BL/6). We obtained 3D locations of new bone formation by performing 'slice and view' 3D fluorochrome mapping of the entire bone and compared these sites with the regions of high fluid velocity or strain energy density estimated using a finite element model, validated with ex-vivo bone surface strain map acquired ex-vivo using digital image correlation. For the comparison, 2D maps of the average bone formation and peak mechanical stimulus on the tibial endosteal and periosteal surface across the entire cortical surface were created. Results showed that bone formed on the periosteal and endosteal surface in regions of high fluid flow. Peak strain energy density predicted only the formation of bone periosteally. Understanding how the mechanical stimuli spatially relates with regions of cortical bone formation in response to loading will eventually guide loading regime therapies to maintain or restore bone mass in specific sites in skeletal pathologies.
骨骼是一种动态组织，会根据生物学和力学因素调整其结构。在此，我们研究在小鼠胫骨轴向加载模型（C57BL/6）中，皮质骨形成如何受到局部力学环境的空间控制。我们通过对整个骨骼进行“切片观察”三维荧光染料映射来获取新骨形成的三维位置，并将这些位点与使用有限元模型估计的高流体速度或应变能密度区域进行比较，该有限元模型已通过使用数字图像相关技术在体外获取的骨表面应变图进行了验证。为了进行比较，我们创建了整个皮质表面胫骨内膜和骨膜表面平均骨形成和峰值力学刺激的二维图。结果表明，在高流体流动区域的骨膜和内膜表面形成了骨。峰值应变能密度仅预测了骨膜处的骨形成。了解机械刺激如何在空间上与加载响应中皮质骨形成区域相关联，最终将指导加载方案疗法，以维持或恢复骨骼疾病特定部位的骨量。
