ABSTRACT
BACKGROUND: Distraction osteogenesis is an effective method for large bone defects, bone tumors and osteomyelitis. However, there is a lack of a standard model in the basic research concerning distraction osteogenesis. OBJECTIVE: To establish a rabbit femoral model of distraction osteogenesis and to assess its osteogenic effect. METHODS: Twenty male New Zealand rabbits were enrolled to establish the rabbit femoral model of distraction osteogenesis using a novel distractor. Subsequently, the gross observation and X-ray examination of the specimens were performed to assess the osteogenic effect. RESULTS AND CONCLUSION: Gross observation: on day 14 after fixation, there were light-colored and dense newborn bones distributing evenly in the distraction gap, and appeared with a columnar connection with the broken ends; the boundary with normal bones became vague. On day 35, the surface of newborn bones in the distraction gap showed the same color and texture with the normal ones, the boundary between the newborn and normal bones was difficult to distinguish, and the bone mineral density was increased notably. Radiology results: on day 14 after fixation, the stent was fixed stably, the broken ends got good reduction, and cloudy shallows connecting the two ends of the normal bones in the distraction gap and increased bone mineral density were detectable. Completely calcified new-born bones, intact bone cortex and open medullary canal were further visible on day 35. These results suggest that the rabbit femoral model of distraction osteogenesis is established successfully using the self-designed single-arm distractor based on rational surgical procedures and standard operations.
ABSTRACT
[Objective]To detect the effect of constant magnetic field on metal ion Co2+,Cr3+ induced TNF-? secreted by human mononuclear cells,and to search a method for prevention and treatment of aseptic loosening. [Methods]CoCl2 powder and CrCl3 powder were dissolved in the asepsis injecting water. Mononuclear cells from human peripheral blood,were taken and cultured with Co2+,Cr3+ ions in different magnetic field of 10Gs,100 Gs,1000Gs for 12,24 and 48 hs. There were nine groups:control group,Co2+ group,Cr3+ group,Co2+andCr3+ with various intensities of constant magnetic field,respectively.ELISA method was applied to detect tumor necrosis factor (TNF-?) in serum via the absorbance (A).[Results]Co2+ and Cr3+ ions stimulated human mononuclear cell to secrete TNF-? (P