Massive segmental bone loss due to chronic osteomyelitis represents a considerable challenge to orthopedic surgeons and is a limb threatening condition.The only option available in such a clinical situation is segment...Massive segmental bone loss due to chronic osteomyelitis represents a considerable challenge to orthopedic surgeons and is a limb threatening condition.The only option available in such a clinical situation is segment transport using the Ilizarov technique of distraction osteogenesis;yet the most common problem in cases of bone transport with the Ilizarov technique in massive bone loss,is the long duration of the fixator.In addition to autologous bone grafting,several mechanical,biologic,and external physical treatment modalities may be employed to promote bone formation and maturation during segment transport in osteomyelitis patients.Mechanical approaches include compressive loading of the distraction regenerate,increased frequency of small increments of distraction,and compression-distraction.Intramedullary nailing and hemicorticotomy can reduce the time in external fixation;however,these techniques are associated with technical difficulties and complications.Exogenous application of low-intensity pulsed ultrasound or pulsed electromagnetic fields may shorten the duration of external fixation.Other promising modalities include diphosphonates,physician-directed use(off-label use)of bone morphogenetic proteins,and local injection of bone marrow aspirate and platelet gel at the osteotomy site.Well-designed clinical studies are needed to establish safe and effective guidelines for various modalities to enhance new bone formation during distraction osteogenesis after segment transfer.展开更多
This paper presents experimental investigation for particles breakage for natural sand. The particle breakage was induced by subjecting the sample to one dimensional compression. Grain size analyses were performed bef...This paper presents experimental investigation for particles breakage for natural sand. The particle breakage was induced by subjecting the sample to one dimensional compression. Grain size analyses were performed before and after induced breakage. Thereafter, the sand shear strength parameters were assessed using direct shear box tests and the coefficient of permeability was assessed using constant head permeameter. Examining the obtained results revealed that the amount of breakage due to one dimensional compression was of order higher than the amount occurring during direct shear test. Peak shear strength parameters decreased with the particles breakage increasing. Moreover, dilation angle of shear strength pronouncedly decreases with the amount of particles breakage increasing. Crushing has obvious effect on the evaluated coefficient of permeability.展开更多
文摘Massive segmental bone loss due to chronic osteomyelitis represents a considerable challenge to orthopedic surgeons and is a limb threatening condition.The only option available in such a clinical situation is segment transport using the Ilizarov technique of distraction osteogenesis;yet the most common problem in cases of bone transport with the Ilizarov technique in massive bone loss,is the long duration of the fixator.In addition to autologous bone grafting,several mechanical,biologic,and external physical treatment modalities may be employed to promote bone formation and maturation during segment transport in osteomyelitis patients.Mechanical approaches include compressive loading of the distraction regenerate,increased frequency of small increments of distraction,and compression-distraction.Intramedullary nailing and hemicorticotomy can reduce the time in external fixation;however,these techniques are associated with technical difficulties and complications.Exogenous application of low-intensity pulsed ultrasound or pulsed electromagnetic fields may shorten the duration of external fixation.Other promising modalities include diphosphonates,physician-directed use(off-label use)of bone morphogenetic proteins,and local injection of bone marrow aspirate and platelet gel at the osteotomy site.Well-designed clinical studies are needed to establish safe and effective guidelines for various modalities to enhance new bone formation during distraction osteogenesis after segment transfer.
文摘This paper presents experimental investigation for particles breakage for natural sand. The particle breakage was induced by subjecting the sample to one dimensional compression. Grain size analyses were performed before and after induced breakage. Thereafter, the sand shear strength parameters were assessed using direct shear box tests and the coefficient of permeability was assessed using constant head permeameter. Examining the obtained results revealed that the amount of breakage due to one dimensional compression was of order higher than the amount occurring during direct shear test. Peak shear strength parameters decreased with the particles breakage increasing. Moreover, dilation angle of shear strength pronouncedly decreases with the amount of particles breakage increasing. Crushing has obvious effect on the evaluated coefficient of permeability.
