A Preliminary Study On The Relationship Between Local Application Of Vancomycin Powder And Infection Of Spinal Fusion Incision And BMP-2 Expression In Rabbits

Objective: To investigate the relationshi P between the local a PPlication of vancomycin Powder and the infection of the incision of the oPeration in rabbits,and to analyze the correlation between the dose of vancomycin and the exPression of BMP-2 in the fusion site.Methods: 48 3-month-old healthy male rabbits were randomly divided into blank control grouP(exPerimental control grouP,n = 16),conventional dose grouP(exPerimental grouP 1,n= 16)and high-dose grouP(exPerimental grouP 2,n = 16).The blank control grouP directly im Planted the Pre Pared autogenous bone slime into the rabbit lumbar Posterior bone grafting bed.The conventional dose grouP added vancomycin Powder into the Pre Pared autogenous bone slime according to the PreoPerative weight of 14.3mg/kg and the high-dose grouP according to the PreoPerative weight of 71.5mg/kg,and the mixture was even and then im Planted into the rabbit lumbar Posterior bone grafting bed.The feeding,drinking water and incision were observed every 8 hours after the oPeration.If there was Purulent secretion in the oPeration,it was characterized as PostoPerative infection and treated with debridement and cefuroxime sodium intramuscular injection for anti infection.All rabbits were killed by air embolism on the 84 th day after the oPeration.The callus at the fusion site was removed for real-time fluorescence quantitative qPCR and immunohistochemical detection of bone mor Phogenesis eggs ExPression of BMP-2.Fisher’s exact Probability method was used for statistical analysis of incision infection,and one-way analysis of variance(ANOVA)was used for statistical analysis of bone mor Phogenetic Protein-2 real-time fluorescence quantification and immunohistochemistry results.Results :(1)Observation results: Four rabbits were infected(infection rate was 25%)in the experimental control group,and no rabbits were infected(infection rate was 0)in the conventional dose group and the high-dose group.The difference between the experimental control group and the conventional dose group was statistically significant(P=0.02<0.05),the difference between the experimental control group and the high-dose group was statistically significant(P=0.02<0.05),and the difference between the conventional dose group and the high-dose group was not statistically significant(P>0.05).(2)Real-time fluorescence quantitative detection of the relative expression of BMP-2 gene: the relative expression of BMP-2 gene was 1.45±0.35 in the control group,1.23±0.12 in the conventional dose group,and 0.34±0.29 in the high-dose group.The difference between the experimental control group and the conventional dose group was not statistically significant(P=0.215>0.05),the difference between the experimental control group and the high-dose group was statistically significant(P=0<0.05),and the difference between the conventional dose group and the high-dose group was statistically significant(P=0<0.05).(3)Immunohistochemical test results of positive cells of BMP-2: The number of positive cells in the control group was 66.38±5.04,the number of positive cells in the conventional dose group was 64.14±4.14,and that in the high-dose group was 37.29±3.64.There was no statistically significant difference between the experimental control group and the conventional dose group(P=0.334>0.05).The difference between the experimental control group and the high-dose group was statistically significant(P=0<0.05).The difference between the conventional dose group and the high-dose group was statistically significant(P=0<0.05).Conclusion :(1)(1)Local application of vancomycin powder in the surgical incision can effectively prevent the infection of the surgical incision in rabbits;(2)Local application of high-dose vancomycin powder resulted in decreased expression level of bone morphogenetic protein(BMP-2)at bone graft fusion site in rabbits,while conventional dosage of vancomycin powder did not affect the expression level of bone morphogenetic protein(BMP-2)at bone graft fusion site in rabbits.