Experimental Study On The Stress And Remodeling Adaptation Of Vivo Bone Tissue And Its Biological Model

The relationship between stress and growth is alive ghost of biomechanics, functional adaptation is a universal rule of biomechanics. The study of relationship between stress and growth mainly includes two aspects: one is to investigate the adaptation procedure of bone growth and remodeling to its stress environment in order to set up a aptitude, accurate, practical and can be quantified "model", which can precisely express how functional adaptation form the inner tissue of bone; The other is to study the relationship between stress environment and cell growth and energy as well as its mechano-biology transduction mechanism at microcosmic point of view in order to essentially illuminate the mechanism of the connection of stress and growth.Although the biomechanics has been studied for more than one century, but it has not formed a mature embranchment up to the present. It is very difficult to introduce mechanical theory into organism, biological tissue and apparatus, because the main characteristic of organism is that it has "life" there is essential difference between the structure of alive tissue and nonliving engineering material.From biomechanical point of view, this research integrates computer simulation technique, three-dimension image reconstruction, computing mechanics, parameter inversion identification theory and animal experiments. Possessing advantages of multiple subjects crossing, it carries through the investigation of bone anatomical structure and mechanical property adapting to its normal function, and creates stress and remodeling adaptation biological model of living bone tissue. The building of this biological model is carried through under macroscopic scale meaning.The main work of each chapter of the research is summarized in the following:In chapter one, the definitions of biomechanics and bone mechanics aremainly expatiated. The brief history, investigation feature, study meaning ofbiomechanics and bone mechanics are simply introduced. And then, the basic concept and essence theory of bone growth and remodeling are presented. The development course of stress and bone remodeling is reviewed. The development status of biomechanics in our country is briefly introduced. At last, the clinic background and research meaning of the thesis are summarized.In the chapter two, the histology and physiology of bone are firstly summarized, then animal experimental model of rat is built, three experimental studies are put up, the influence of different stress environment on the macroscopic geometrical structure, anatomy, tectology, metrology, bone density and biomechanical property of rat femur is investigated systematically. How the stress environment affects rat femur growth and remodeling is discussed. The experiment result shows that living bone tissue adapts its environment by changing its structure, shape, tissue component and biomechanical property. In chapter three, rat tibia fracture model is created, the influence of stress environment on animal fracture healing at tissue level and molecule level is studied from medical and biomechanical point of view; the mechanism of stress and remodeling is discussed at tissue and mechanocytobiology level respectively. The research shows that stress environment can influence the proliferation and differentiation of mesenchymal cell, at the same time, it also affect the expression of extracellular matrix molecules and the immigration of macrophages, further more change the interaction of cells which participate in fracture healing.At last, a finite element analysis of the effect of open section within a long bone on its mechanical property and stress distribution is carried through, the obtained conclusion provides a valuable reference to clinical orthopaedic operation.The chapter four is the keystone content of the thesis. At first, the development status in quo of living bone tissue stress and remodeling adaptation biomechanical model is particularly introduced, and then, on the basis of animalbiomechanical model is particularly introduced, and then, on the...