Skeletal Biology Group, Comparative Biomedical Sciences, The Royal Veterinary College, Royal College Street, London NW1 0TU, UK.
Max Planck Institute of Colloids and Interfaces, Department of Biomaterials, Research Campus Golm, 14424 Potsdam, Germany.
Sci Adv. 2020 Mar 6;6(10):eaax8301. doi: 10.1126/sciadv.aax8301. eCollection 2020 Mar.
Bones adapt to mechanical forces according to strict principles predicting straight shape. Most bones are, however, paradoxically curved. To solve this paradox, we used computed tomography-based, four-dimensional imaging methods and computational analysis to monitor acute and chronic whole-bone shape adaptation and remodeling in vivo. We first confirmed that some acute load-induced structural changes are reversible, adhere to the linear strain magnitude regulation of remodeling activities, and are restricted to bone regions in which marked antiresorptive actions are evident. We make the novel observation that loading exerts significant lasting modifications in tibial shape and mass across extensive bone regions, underpinned by (re)modeling independent of local strain magnitude, occurring at sites where the initial response to load is principally osteogenic. This is the first report to demonstrate that bone loading stimulates nonlinear remodeling responses to strain that culminate in greater curvature adjusted for load predictability without sacrificing strength.
骨骼根据严格的原则来适应机械力，这些原则预测出笔直的形状。然而，大多数骨骼都是具有反常曲率的。为了解决这个悖论，我们使用基于计算机断层扫描的四维成像方法和计算分析，来监测急性和慢性的整体骨骼形状适应和重塑。我们首先证实，一些急性负载引起的结构变化是可逆的，符合重塑活动的线性应变幅度调节，并局限于明显抗吸收作用的骨骼区域。我们做出了新颖的观察，即在主要是成骨的部位，负载会对胫骨形状和质量产生广泛的、持久的影响，而这种影响不受局部应变幅度的影响，这是由独立于局部应变幅度的重塑来支撑的。这是第一个报告表明，骨加载刺激了非线性的应变重塑反应，最终导致了更大的曲率调整，以适应可预测的负载，而不会牺牲强度。
