Objective To summarize the occurrence mechanism of backside wear, the method of evaluating backside surface damage, the relationship between backside wear and osteolysis in acetabulum, and the approach to reduce backside wear in total hip arthroplasty with modular acetabulum prosthesis. Methods The recent articles about the backside wear in acetabular liners were extensively reviewed. Results Backside wear in acetabular liners is connected with micromotion between the liner and the shell, rough interface, thickness of the liner, and impingement. The methods to evaluate backside wear damage are only proceeded in revised acetabular liners. Backside wear can generate polyethylene particles that is likely related to the process of osteolysis in acetabulum through the screw holes of metallic shell. To reduce backside wear between the liner and the shell, measures such as improved locking mechanisms, smooth inner metallic shell, maximized shell liner conformity, improving the quality of polyethylene, and reducing impingement can be taken. Conclusion There is no method of evaluating the backside wear in vivo. The relationship between backside wear and osteolysis in acetabulum as well as aseptic loosening of acetabulum prosthesis is controversial.
Objective To systematically assess the therapeutic effect of rivaroxaban and enoxaparin on preventing deep venous thrombosis after major orthopedic operation. Methods Such databases as MEDLINE, EMbase, The Cochrane Library (Issue 3, 2009), Current Controlled Trials, The National Research Register, CBM, and CNKI were searched from their establishment to December 2009 in whatever language. Related journals were handsearched as well. Randomized controlled trials (RCTs) of comparing therapeutic effects of rivaroxaban and enoxaparin on preventing deep venous thrombosis after major orthopedic operation were included. Data were extracted and their quality was evaluated, and meta-analyses were conducted by using RevMan 5.0.25 software. Results Seven RCTs with 15 458 patients were included. The results of meta-analyses showed that compared with enoxaparin, rivaroxaban reduced the end risk of the primary efficacy to 60% (RR=0.40, 95%CI 0.28 to 0.57, Plt;0.000 01) and reduced the end risk of the main secondary efficacy to 71% (RR=0.29, 95%CI 0.15 to 0.56, Plt;0.000 01), and the end risk of other efficacy to 56% (RR=0.44, 95%CI 0.29 to 0.66, Plt;0.000 01). During the treatment, rivaroxaban and enoxaparin displayed similarity in terms of the incidence of serious bleeding events (RR=1.16, 95%CI 0.68 to 1.999, P=0.59) and the secondary safety endpoint. Conclusion Rivaroxaban is effective in preventing deep venous thrombosis after major orthopedic operation and can significantly reduce the risk of postoperative deep vein thrombosis.
Type 1 diabetes mellitus (T1DM) is an autoimmune disease in which pancreatic β cells are destroyed, resulting in an absolute lack of insulin. Intestinal microbiota and its metabolites can promote the progression of T1DM by destroying pancreatic β cells, increasing insulin resistance, increasing intestinal permeability, interfering with immune response. Therefore, fecal microbiota transplantation is expected to become a new method for preventing and treating T1DM in the future. This article mainly explores possible pathways for the application of fecal microbiota transplantation in T1DM, including protection of pancreatic β cells, improving insulin resistance, reducing intestinal permeability, and regulating immune responses.
ObjectiveTo investigate the formation of nanostructure on cuttlefish bone transformed hydroxyapatite (CB-HA) porous ceramics and the effects of different nanostructures on the osteoblasts adhesion, proliferation, and alkaline phosphatase (ALP) expression.MethodsThe cuttlefish bone was shaped as plate with diameter of 10 mm and thickness of 2 mm, filled with water, and divided into 4 groups. The CB-HA in groups 1-4 were mixed with different phosphorous solutions and then placed in an oven at 120℃ for 24 hours. In addition, the samples in group 4 were further sintered at 1 200℃ for 3 hours to remove nanostructure as controls. The chemical composition of CB-HA were analyzed by X-ray diffraction spectroscopy, Fourier transform infrared spectrum, and inductively coupled plasma (ICP). The physical structure was analyzed using scanning electron microscopy, specific surface tester, and porosity tester. The MC3T3-E1 cells of 4th generation were co-cultured with 4 groups of CB-HA. After 1 day, the morphology of the cells was observed under scanning electron microscopy. After 1, 3, and 7 days, the cell proliferation was analyzed by MTT assay. After 7 and 14 days, the ALP expression was measured by pNPP method.ResultsX-ray diffraction spectrum showed that the four nanostructures of CB-HA were made of hydroxyapatite. The infrared absorption spectrum showed that the infrared absorption peak of CB-HA was consistent with hydroxyapatite. ICP showed that the ratio of calcium to phosphorus of all CB-HA was 1.68-1.76, which was consistent with hydroxyapatite. Scanning electron microscopy observation showed that the nanostructure on the surface of CB-HA in groups 1-3 were large, medium, and small cluster-like structures, respectively, and CB-HA in group 4 had no obvious nanostructure. There were significant differences in the specific surface areas between groups (P<0.05). There was no significant difference in the porosity between groups (P>0.05). Compared with group 4, groups 1-3 have more pores with pore size less than 50 nm. After co-cultured with osteoblasts, scanning electron microscopy observation and MTT assay showed that the cells in groups 2 and 3 adhered and proliferated better and had more ALP expression than that in groups 1 and 4 (P<0.05).ConclusionThe size of cluster-like nanostructure on the surface of CB-HA can be controlled by adjusting the concentration of ammonium ions in the phosphorous solution, and the introduction of small-sized cluster-like nanostructure on the surface of CB-HA can significantly improve the cell adhesion, proliferation, and ALP expression of the material which might be resulted from the enlarged surface area.