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Objective: To investigate a practical, effective, with fewer side effects with external fixation screws itself prevent infection, and comparative analysis of pathogen contamination of animal models of infection prevention experiment to demonstrate the feasibility of this method and superiority, and antibacterial mechanism, provide an objective basis for late-stage clinical applications and theoretical support. Method: 1. Material: stainless steel external fixation screws, HA powder, FumatT200-4 antibacterial powder, Staphylococcus aureus suspensions (ATCC 25923 standard strain) in experimental animals healthy New Zealand white rabbits, 3-6 months of age. Antibacterial test animals to prevent infection experimental specimen groups: experimental group: silver loaded hydroxyapatite-coated external fixation screw group, the control group: stainless steel external fixation screws group 3. Experimental model preparation: 95wt% hydroxyapatite powder with 5wt% FumatT200-4 anti-bacterial powder mixing, application of vacuum plasma spraying equipment for stainless steel external fixation screws line plasma spraying. Experimental group and the control group outside the fixed needle be disinfected spare, big ears healthy New Zealand white rabbits, a total of 24 production pollution model, the average weight of 2.32 ± 0.06Kg, 13 females, 11 males, were randomly divided into 2 random row list law groups, each group of 12 rabbits were to ketamine 50mg/kg line muscle anesthesia. Were placed in a stainless steel outer fixing screws and hydroxyapatite coating containing silver external fixation screws, after injection of Staphylococcus aureus suspension. The common dietary Environment dietary. Two external fixation screws the fixed needle tract Staphylococcus aureus rabbit outside pollution preventive role model. Specimen collection and data collection methods: postoperative days 1, 3, 7, 14 and 28 days rabbit body temperature, weight measurement, specimens from blood specimens and blood count, C-reactive protein detection. 1,3,7,14,28 after day of the needle tract surrounding tissue for pathological examination. Organizations a common culture of bacteria. 1.24 femur placed outside the fixed needle and preparation of Staphylococcus aureus pollution model rabbit. Experimental procedure occurred rabbit died complement 24. Last a total of 26 completed the experiment, n = 12, 15 female, 11 male. The experimental group 2 infection, infection control group control group of 11, the infection rate of the experimental group and the control group with significant difference (P lt; 0.05). The weight of the experimental group and the control group White Rabbit 1, 3, 7, 14 and 28 days after surgery (P gt; 0.05), the difference was not statistically significant. Experimental group and a control group of white rabbits rectal temperature after 1, 3, 7, 14 and 28 days (P gt; 0.05), the difference was not statistically significant. The experimental group White Rabbit venous blood leukocyte count and CRP levels in 3, 7, and 14 days after surgery were significantly lower than those in the control group (P lt; 0.05), the difference was statistically significant. However, after 1 day and 28 days, the control (P lt; 0.05) showed no significant difference between the two groups. Infection White Rabbit part abscess formation, the around skin irritation, some accompanied by pus spills. The external fixation needle around the yellow-white pus attachment around necrotic tissue. The infected white rabbits were taken secretions pus bacterial culture were cultured S. aureus. Outside fixed needle around histopathological examination (HE staining) visible: white rabbits around the outer fixed needle infected tissue necrosis, a large number of neutrophils, lymphocytes, monocytes aggregation. The late see the coexistence of fibrous tissue and necrotic lesions. The conclusions are contained silver hydroxyapatite coating of external fixation needle the rabbit external fixation pin tract Staphylococcus aureus contamination model can be effective in preventing infection. Provide adequate practical basis for the next transition to clinical application.
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