骨的疲劳损伤和修复

Fatigue Damage and Repair in Bone

骨是人体承担力学功能的器官。习惯性生理运动范围内中等应力 /应变水平就能引起骨的疲劳损伤 ,激烈运动甚至引起骨折。骨疲劳损伤的实质是骨基质上产生比典型裂纹更小的裂纹 ,此种裂纹也可能出现在胶原和羟基磷灰石晶体水平。但骨能对基质损伤进行修复 ,即对损伤区的骨质吸收 ,然后替换新骨质。骨细胞通过损伤的细胞突和调整性细胞死亡发出骨损伤基质吸收的信号 ,骨细胞在骨基质损伤修复过程中起重要的作用。骨的疲劳和修复是骨的一种生理现象 ,研究者们把此过程用数学、力学模型定量化描述 。

Bone is a load-bearing organ in human body. Fatigue damage occurs readily at the modest loads to which bone is subjected during its habitual physiological usage. Even bone fracture may occur during vigorous activity. The nature of fatigue damage is that in bone there are very fine microcracks which are smaller than typical microcracks, and may occur at the level of hydroxyapatite crystals. But bone can repair microdamage by bone remodeling. Osteocytes play an important role of signaling during bone remodeling. Some researchers attempted to describe the process of bone fatigue damage and repair by mathematic, mechanical models in order to understand it well and to apply it well in clinical practice.