摘要废用性骨质疏松症是由于运动能力受限、功能障碍或失重引起骨骼处于无负荷或机械力减少的状态,继而出现全身性或局部性矿物质减少和骨丢失所致的骨质疏松.作为骨组织中力学感受器的骨细胞陷窝-骨小管系统在外力作用下,骨小管内液流动,对骨细胞突起的微丝产生剪切力和电压.在成骨细胞之间力学信号以电流形式传递.同时,微丝受到的外力传递至骨细胞膜表面的整合素,并通过肌动蛋白传递至整个细胞骨架,使与其物理连接的各种因子与酶产生变形,进而发生化学反应,从而调节骨重建过程.当外力减少或缺乏时骨组织产生小于骨重建阈值的应变从而影响上述过程,使骨形成不能满足骨吸收,最终形成废用性骨质疏松症.在此疾病的力学研究中常用的测试方法包括拉伸试验、压缩试验、弯曲试验、扭转试验等.许多力学研究表明锻炼主要通过两条途径来预防和治疗废用性骨质疏松症.一条途径为外力作用于骨组织,通过上述力学影响骨重建的机制来促进骨组织形成.另一条途径为锻炼可通过提高神经生长因子分泌、调节钙平衡以及体液调节来提高体内骨矿含量,最终提高骨密度.本文主要从组织、细胞、分子水平介绍力学因素导致废用性骨质疏松症的机制,以及力学在废用性骨质疏松症的预防和治疗中的作用,以便于相关领域研究者们从力学角度进一步了解废用性骨质疏松症的发病机制和防治.

abstractsDisuse osteoporosis is a kind of osteoporosis correlated with movement limitation,disorder or weightlessness which let bone be in the condition of unloading or mechanical stress reduction.And general or local mineral substance reduction and bone loss happen subsequently.When the bone lacunar-canalicular system which is the sensory receptor of osseous tissue affected by force,fluid in bone canaliculi flows subsequently.Both of shear force and voltage produced by the flowing fluid act on microfilaments on protuberance of osteocyte.Mechanical signals transfer in the form of electric current among osteoblasts.Meanwhile,the microfilaments are affected by force which would be transferred to the whole cytoskeleton through an actin linked to an integrin on the surface of osteocyte membrane.Factors and enzymes physically connected to the cytoskeleton would be deformed.Bone reconstruction will be regulated by chemical reactions produced by the deformation afterwards.However,reduction or lack of force may generate strains less than threshold of bone reconstruction which would affect bone reconstruction process mentioned above.The change of process results in a phenomenon that bone generation can not keep up with bone resorption and disuse osteoporosis may happen.Common mechanical test methods used in the studies on disuse osteoporosis contain tensile test,compression test,bending test,torsion test,and so on.Many studies present exercise may lead to prevention and treatment of disuse osteoporosis through two approaches.One of the approaches is that bone reconstruction mechanism mentioned above affected by force lead to promoting generation of bone tissue.The other one is that bone mineral density is increased in the result of improvement of nerve growth factors secretion,regulation of calcium balance and humoral regulation via exercise.The article is an introduction to mechanism,prevention and treatment of disuse osteoporosis led by mechanical factors in the level of tissue,cell,and molecule.It may provide convenience for researchers in relative fields to understand mechanism,prevention and treatment of disuse osteoporosis in the perspective of mechanics.