| Objectives By establishing a rat distraction osteogenesis model with different extension lengths,the differences in the healing index of different extension lengths and the changes of serum interleukin-1 and interleukin-6 concentrations in rats at different times of the distraction period were explored,which is the basis for clinical osteogenesis.The selection of surgical methods for defects and other diseases provides experimental evidence.Methods Fifty-six male SD rats were randomly divided into 7 groups(A-G groups),8rats in each group,and they were individually housed in cages,provided with appropriate humidity and temperature,and maintained a daily light-dark cycle of 12 hours.The left femur was inserted with a threaded needle and an external fixator was installed,followed by a mid-segment osteotomy.After a 7-day incubation period,the extension was carried out at a speed of 0.5mm/d,divided into two times in the morning and evening,each time extended by 0.25 mm,and the groups were extended by 2.0mm(group A),4.0mm(group B),and 6.0mm respectively.(Group C),8.0 mm(Group D),10.0 mm(Group E),12.0 mm(Group F),14.0 mm(Group G).At the end of the stretch period,3 rats in each group were randomly selected to be sacrificed,and the serum samples were kept.The serum samples were analyzed by enzyme-linked immunosorbent assay(Elisa).The change trend of IL-1and interleukin 6(IL-6)concentrations.Except that the rats were randomly sacrificed at the end of the distraction period,the remaining 5 rats entered the mineralization period,and the bone healing in the extension area was continuously observed by X-ray until the tricortical shadow was formed in the extension area and the medullary cavity was recanalized.The healing time was recorded and the healing index(mineralization time of extension zone/length of extension)was calculated.The SPSS 21.0 software was used for statistical analysis and function diagrams of the seven groups of healing indices.The difference of healing index under different extension lengths was evaluated;the concentrations of IL-1 and IL-6 in serum of rats at different times during the stretch period were statistically analyzed.Results There was a statistically significant difference in the healing index between the groups A and F(P<0.05),but there was no statistical difference between the groups A and B(P>0.05),and there was no statistical difference between the four groups(P>0.05)(P>0.05),the healing index of groups A and B was higher than that of groups C,D,E,and F;there was no significant difference in the serum IL-1 concentration of the rats at different times during the stretch period(P>0.05),and the serum IL-6 concentration existed Statistical difference(P<0.05),serum IL-6 concentration was higher in the early stretch(the 8th day of stretch)and late stretch(the 24 th and 28 th day of the stretch).Conclusions 1 In the rat distraction osteogenesis model,the different extension length will affect the healing index.When the extension length is shorter(2-4mm),the higher the healing index,the longer the unit healing time required;2 In distraction At different times of the distraction stage of osteogenesis,the level of IL-1 in serum did not change significantly,and the distraction force could not significantly induce and promote the secretion of IL-1;3 At different moments of the distraction period The levels of IL-6 in the serum showed different levels.The serum IL-6 concentration increased in the early stretch(the 8th day of the stretch period)and the late stretch(the 24 th and 28 th days of the stretch period).It is specifically induced under the action of tensile force.Figure22;Table7;Reference 128... |
PDF Full Text Request