骨功能适应性重建模型及数值模拟

Remodeling Models and Numerical Simulation of Bone Functional Adaptation

骨骼会受到力学因素的影响和调控,发生骨功能适应性重建。建立模拟骨重建的数值模型,定量地研究骨重建过程,有着重要的临床应用价值。目前,骨功能适应性重建模型可分为两大类:力学模型和生理模型。对这两类重建模型的原理、算法和应用等做详细论述。力学模型通过假设力学环境与骨结构之间的函数关系来预测骨重建,但不考虑其真实的生物学过程。基于不同的重建激励主要有两种力学模型:骨力学稳态模型和骨损伤修复模型。生理模型则试图从微观层次阐明骨重建的力学-生物学机制,骨重建是由破骨细胞、成骨细胞等各种骨组织细胞完成,有以基本多细胞单位的形式作用或细胞独立分开作用两种观点。这些重建模型结合有限元法应用在许多有关骨重建问题的数值计算中。通过比较分析多个数值应用的模拟结果,还讨论了重建控制方程中各参数值的设置对重建结果的影响。

Functional adaptation of bone occurs due to the influence and regulation of mechanical factors. Establishment of numerical model and quantitative analysis for bone remodeling process has significant clinical value. Nowadays, models developed in the literature to simulate the functional adaptation of bone fall into two classes： mechanical models and physiological models. This paper reviews bone remodeling models from several aspects, including theories, algorithms and applications. Mechanical models are able to predict bone remodeling through direct relationships between mechanical stimulus and bone structures, but no actual biological processes are considered. According to different remodeling stimuli, mechanical models mainly include mechanostat models and maintenance models. Physiological models try to unravel the role of the mechanical environment in the biological mechanisms involved in bone remodeling. Different types of cells are involved in bone remodeling process： osteoclasts, which resorb bone, and osteoblasts, which deposit bone. Based on different hypotheses, these cells are thought to work separately or as basic muhicellular units. Remodeling models are normally implemented in finite element programs to enable numerical solution of problems related to bone remodeling. Based on several application examples, parametric investigation of remodeling equations is discussed as well.