The physis of a long bone may get ＇sandwiched＇ and crushed between the metaphysis and the epiphysis if it is traumatically loaded along its long axis. Such a physeal injury may lead to complications like angular def...The physis of a long bone may get ＇sandwiched＇ and crushed between the metaphysis and the epiphysis if it is traumatically loaded along its long axis. Such a physeal injury may lead to complications like angular deformities and growth restrictions and hence, management of such injuries requires adequate planning and attentive execution. Two patients with distal femoral physeal crush injury were treated using a ring fixator such that one ring had the wires passing through the epiphysis and the other through the femoral shaft. On table image intensifier controlled distraction of the crushed physis was done to bring the height of the physis similar to that of the opposite limb. Patients were followed up for more than two years clinically and radio- logically. There was no clinical or radiological angular deformity of the operated limbs. MRI scans showed intact physes with no physeal bar formation in either of the two patients. The distraction obtained by the ring fixator appears to have provided ample ＇breathing space＇ to the compressed physis and that the growth potential may have been re-gained by the procedure. However, two years is a relatively short duration of follow-up and further follow-up of longer duration and in greater number of patients is needed to gauge the actual effectiveness of the technque used bv us.展开更多
The growth plate is a thin layer of cartilage sandwiched between epiphyseal and metaphyseal bone and is the location of active bone growth during childhood. It is subjected to large compressive and shear forces while ...The growth plate is a thin layer of cartilage sandwiched between epiphyseal and metaphyseal bone and is the location of active bone growth during childhood. It is subjected to large compressive and shear forces while protecting its resident chondrocytes from damage. We believe that computational modeling can help us better understand how the macro-scale loads are transmitted to micro-scale stresses and strains within the growth plate cartilage. As a first step in this process we analyzed the mechanical response of compression experiments performed on bovine bone/growth plate/bone samples. We endeavored to estimate the modulus of elasticity of the growth plate itself by simulating the compression experiments of these specimens using the finite element method. It is shown that when the growth plate in the compression specimens was modeled as a flat layer, the state of stress in the cartilage was triaxial and non-uniform with the hydrostatic stress being much greater than the octahedral shear stress over most of the central region of the growth plate test samples. The computational models accounted for variations in the average cartilage thickness, the non-uniaxial, non-uniform and triaxial state of stress in the thin cartilage layer, and for the estimated extrinsic compliance resulting from compression of the variable heights of bone on either side of the growth plate cartilage. However, due to lack of information on the internal structure of each sample, the models did not account for the variations in the non-flat topography of the growth plates. The models also did not include the calcified cartilage layer. Further model development is recommendedin order to determine the degree to which accounting for the complex growth plate topography influences the predicted cartilage modulus of elasticity.展开更多
Tibb also known as Unani-Tibb,Greco-Arab,Western Holistic,Unani and Persian medicine,is an ancient holistic medical system that originated approximately 10000 years ago,based on the humoral and temperamental theories ...Tibb also known as Unani-Tibb,Greco-Arab,Western Holistic,Unani and Persian medicine,is an ancient holistic medical system that originated approximately 10000 years ago,based on the humoral and temperamental theories that was hypothesised by Hippocrates and Galen.The“completeness”of this medical discipline as“a science of medicine-the art of care”was greatly influenced by renowned scholars including Ibn Sina during the 9th and 13th century,who refined the philosophical principles of;physis,temperament,humours,and the six lifestyle factors,of which physis,the body’s natural ability to heal itself,is a primary principle in the maintenance and restoration of health.Tibb as“a science of medicine”is detailed within the context of Ibn Sina’s principle of cause and effect and the“art of care”is highlighted in the holistic and fully integrative approach of Tibb,based on its philosophical principles.The paper concludes with a brief comparison between Tibb and Western medicine.展开更多
In Physics B 1, Aristotle establishes a detailed definition ofphysis. For that purpose, Aristotle distinguishes physis from rechne and his domain. He did this to offer a satisfactory account of the physical being. In ...In Physics B 1, Aristotle establishes a detailed definition ofphysis. For that purpose, Aristotle distinguishes physis from rechne and his domain. He did this to offer a satisfactory account of the physical being. In this process, phf;sis is defined as an immanent principle of movement and as matter and as form. As matter physis could be understood as ＂the primary underlying matter in each case, of things which have in themselves a source of their movements and changes＂. To consider physis as form Aristotle appeals to four arguments where priority of form over matter appears to be evident and where the identifying of eidos/morphe with to telos/to hou heneka will be crucial, especially for later developments. The reconstruction of Aristotle＇s reasoning on his definition ofphysis in Physics B 1 emphasizing the problems that such effort of definition implies is the purpose of this paper.展开更多
文摘The physis of a long bone may get ＇sandwiched＇ and crushed between the metaphysis and the epiphysis if it is traumatically loaded along its long axis. Such a physeal injury may lead to complications like angular deformities and growth restrictions and hence, management of such injuries requires adequate planning and attentive execution. Two patients with distal femoral physeal crush injury were treated using a ring fixator such that one ring had the wires passing through the epiphysis and the other through the femoral shaft. On table image intensifier controlled distraction of the crushed physis was done to bring the height of the physis similar to that of the opposite limb. Patients were followed up for more than two years clinically and radio- logically. There was no clinical or radiological angular deformity of the operated limbs. MRI scans showed intact physes with no physeal bar formation in either of the two patients. The distraction obtained by the ring fixator appears to have provided ample ＇breathing space＇ to the compressed physis and that the growth potential may have been re-gained by the procedure. However, two years is a relatively short duration of follow-up and further follow-up of longer duration and in greater number of patients is needed to gauge the actual effectiveness of the technque used bv us.
文摘The growth plate is a thin layer of cartilage sandwiched between epiphyseal and metaphyseal bone and is the location of active bone growth during childhood. It is subjected to large compressive and shear forces while protecting its resident chondrocytes from damage. We believe that computational modeling can help us better understand how the macro-scale loads are transmitted to micro-scale stresses and strains within the growth plate cartilage. As a first step in this process we analyzed the mechanical response of compression experiments performed on bovine bone/growth plate/bone samples. We endeavored to estimate the modulus of elasticity of the growth plate itself by simulating the compression experiments of these specimens using the finite element method. It is shown that when the growth plate in the compression specimens was modeled as a flat layer, the state of stress in the cartilage was triaxial and non-uniform with the hydrostatic stress being much greater than the octahedral shear stress over most of the central region of the growth plate test samples. The computational models accounted for variations in the average cartilage thickness, the non-uniaxial, non-uniform and triaxial state of stress in the thin cartilage layer, and for the estimated extrinsic compliance resulting from compression of the variable heights of bone on either side of the growth plate cartilage. However, due to lack of information on the internal structure of each sample, the models did not account for the variations in the non-flat topography of the growth plates. The models also did not include the calcified cartilage layer. Further model development is recommendedin order to determine the degree to which accounting for the complex growth plate topography influences the predicted cartilage modulus of elasticity.
文摘Tibb also known as Unani-Tibb,Greco-Arab,Western Holistic,Unani and Persian medicine,is an ancient holistic medical system that originated approximately 10000 years ago,based on the humoral and temperamental theories that was hypothesised by Hippocrates and Galen.The“completeness”of this medical discipline as“a science of medicine-the art of care”was greatly influenced by renowned scholars including Ibn Sina during the 9th and 13th century,who refined the philosophical principles of;physis,temperament,humours,and the six lifestyle factors,of which physis,the body’s natural ability to heal itself,is a primary principle in the maintenance and restoration of health.Tibb as“a science of medicine”is detailed within the context of Ibn Sina’s principle of cause and effect and the“art of care”is highlighted in the holistic and fully integrative approach of Tibb,based on its philosophical principles.The paper concludes with a brief comparison between Tibb and Western medicine.
文摘In Physics B 1, Aristotle establishes a detailed definition ofphysis. For that purpose, Aristotle distinguishes physis from rechne and his domain. He did this to offer a satisfactory account of the physical being. In this process, phf;sis is defined as an immanent principle of movement and as matter and as form. As matter physis could be understood as ＂the primary underlying matter in each case, of things which have in themselves a source of their movements and changes＂. To consider physis as form Aristotle appeals to four arguments where priority of form over matter appears to be evident and where the identifying of eidos/morphe with to telos/to hou heneka will be crucial, especially for later developments. The reconstruction of Aristotle＇s reasoning on his definition ofphysis in Physics B 1 emphasizing the problems that such effort of definition implies is the purpose of this paper.
