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Objective To compare the knee function in patients with intraoperative medial collateral ligament(MCL)injury treated with or with?out increased prosthetic constraint. Methods The records of 19 cases who encountered with iatrogenic injury to the MCL during total knee arthro?plasty(TKA)between January 2005 and December 2010 were retrospectively reviewed. Eight patients(LCCK group)were treated with increased prosthetic constraint;the remaining 11 patients(LPS group)received increased prosthetic constraint between January 2005 and December 2010 served as controls. The MCL was repaired after TKA. The complications were observed after operation. Knee society scores(KSS)subjective knee scores were used to assess the knee function. No patient was lost for follow?up. The mean follow?up was 5 years. Results Until last follow?up(60 months),The KSS subjective score was 87.4 for LCCK group compared with 93.3 for the LPS group. No revisions for knee instability were per?formed in the 11 patients treated with non?prosthetic constraint;however,2 patients treated with increased prosthetic constraint were revised due to joint loosening. Conclusion The MCL tear should be repaired during TKA;the type of the prosthesis should not be increased when MCL injury is recognized during TKA.
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BACKGROUND: Present studies have proved that titanium coating nanotubes cannot only promote the biological activity of the material itself, but also be used as a drug carrier loading antibiotics and growth factors. OBJECTIVE: To investigate the antibacterial properties of vancomycin/hydroxyapatite/titanium dioxide nanotubes in vitro and in vivo. METHODS: The releasing property in vitro of vancomycin/hydroxyapatite/titanium dioxide nanotubes and vancomycin/titanium dioxide nanotubes were detected. And 1010/L Staphylococcus aureus dilution was put onto the commercial titanium, titanium dioxide nanotube and vancomycin/hydroxyapatite/titanium dioxide nanotube, respectively. Twenty-four hours later, the bacterial growth and activity was observed by scanning electron microscope and confocus scanning electron microscope, respectively. RESULTS AND CONCLUSION: Scanning electron microscope showed: the number of Staphylococcus aureus was the least on the vancomycin/hydroxyapatite/titanium dioxide nanotube, and the bacterial morphology was destroyed. Confocus scanning electron microscope observed: the number of bacteria and viable bacteria was the least on the vancomycin/hydroxyapatite/titanium dioxide nanotube, and the most on the commercial titanium. Besides, the releasing time of vancomycin from the hydroxyapatite/titaniumdioxide nanotube was up to 18 days, but the releasing time of vancomycin was only 4 hours from the titanium dioxide nanotube. In conclusion, the vancomycin/hydroxyapatite/titanium dioxide nanotube has good antibacterial property and slow-releasing performance.
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BACKGROUND:In order to overcome the shortcomings of single materials, antibiotics-loaded hydroxyapatite/titanium composites have attracted people’s attentions. OBJECTIVE:To evaluate the biocompatibility of vancomycin/hydroxyapatite/titanium nanotubes. METHODS:Mouse osteoblasts, MC-3T3-E1, were co-cultured with titanium (Cp-T), TiO2nanotubes, and vancomycin/hydroxyapatite/titanium nanotubes, respectively. Cel morphology and growth were observed after 1, 3 and 5 days of co-culture under inverted microscope and scanning electron microscope. The cel proliferation was detected by AO-EB method. The total protein, calcium and alkaline phosphatase levels were detected at 7 and 14 days of co-culture. RESULTSAND CONCLUSION:The MC-3T3-E1 cels with good viability and morphology adhered wel on the surface of vancomycin/hydroxyapatite/titanium nanotubes compared with those on the surface of pure titanium and TiO2nanotubes under the scanning electron miscroscope. Moreover, there were a large amount of pseudopodia on the surface of composite nanotubes. Compared with the other two groups, the cel number on the surface and the levels of intracelular calcium and alkaline phosphatase were al higher in the vancomycin/hydroxyapatite/titanium nanotubes group. These findings suggest that the vancomycin/hydroxyapatite/titanium nanotubes have good biocompatibility and no cytotoxicity.
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Objective To investigate the molecular mechanism of the glucocorticoid?induced osteoblasts apoptosis,and to develop the effective intervention measures. Methods The MC3T3?E1 cells were treated with different concentrations of dexamethasone for 24 hours,then the apoptosis rate was detected with TUNEL analysis,the intracellular expression of Bim and Bax were determined by Westen blot. In addition,MC3T3?E1 cells were randomly divided into Bim?siRNA group,negative control siRNA group and control group. Twenty?four hours after transfection,10-4mmol/L dexamethasone was added to each group of cells for another 24 hours administration. The apoptosis rate was analyzed using the TUNEL,the mito?chondrial transmembrane electric potential was detected by flow cytometry after JC?1 staining,the expression of Bax,Bcl?2 in mitochondrial and Cyt?C,AIF in cytosolic were determined by Western blot. Results The rate of osteoblast apoptosis and Bim expression in cells were both significantly in?creased with the dosage of dexamethasone,there was no significant difference between the groups in the expression of Bax;the rate of osteoblast apop?tosis after the expression of silence Bim was significantly lower than the negative control siRNA group and control group,the expression of Bax and Cyt?C,AIF in cytosolic were significantly reduced,and the mitochondrial transmembrane electric potential was increased. Conclusion Bim is the key molecules in hormone?induced apoptosis of osteoblasts ,the expression of silence Bim can inhibit dexamethasone induced osteoblasts apoptosis through the mitochondrial pathway.
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Objective To explore the influence of abnormal mechanical stress on acetabular development, especially on the chondrocyte proliferation in acetabular growth plate, and to research the methods of the repair of acetabular dysplasia. Methods 60 Wistar rats of 3 weeks old were divided into three groups, and each group had twenty rats. The left side was experimental side, and the right side was control. In group A, the hip joint was dislocated by manipulation repeatedly within two weeks; in group B, the model of acetabular dysplasia was created by keeping the knee joint in extension through steel needle fixation. The needle was removed after two weeks of fixation; and in group C, the knee joint was fixed in continuous extension with steel needle. When at 5, 7, 9 and 12 weeks old, the rat acetabulum was observed through the soft X-ray photograph, histological method and electronic micrograph respectively. Results In group A, when the rat was 5 weeks old, the acetabular angle was larger roughly 5? than the control side. Malalignment of chondrocyte column in proliferative zone was observed. No difference was seen between the two sides at 7, 9 and 12 weeks old. In group B, when the rats was 5 weeks old, the acetabular angle increased compared to the control side. When the rat was 7 weeks old, malalignment of the chondrocyte column in proliferative and hypertrophic zone increased. When at 9 and 12 weeks old, histological changes became indistinct gradually. In group C, the acetabular angle kept increasing to the control side. The acetabular dysplasia became obvious and had no improving tendency. When the rat was 12 weeks old, the acetabular edge became adducting and flat. There was no obvious alignment of chondrocyte column. The nucleus of acetabular chondrocyte of the proliferative zone became smaller, endoplasmic reticulum and mitochondria decreased, and bubbles formed. Conclusion Acetabular dysplasia could recover when abnormal mechanical stress was released, and the congruence of the head and acetabulum were corrected in the highly growing period of acetabulum. The crucial reason to acetabular dysplasia is the metabolic changes of chondrocytes in proliferative zone of growth plate, which leads to tardy ossification of the acetabulum.