BACKGROUND: Clinical studies demonstrate that the durable stability of the prosthesis depends on a close geometric fit between the prosthesis and femoral medullary cavity.OBJECTIVE: To study the law of the parameters of medullary canal section shape in proximal femur DESIGN: Repeated measurement observation.SETTING: Department of Orthopaedics, Ninth People's Hospital, School of Medicine, Shanghai Jiaotong University MATERIALS: Ten femoral samples without any damage was obtained from corpse in the Staff Room of Anatomy of the Shanghai Second Medical University METHODS: The experiment was carried out in the Department of Or thopaedics, Ninth People's Hospital between January 2000 and March 2000. Section morphology of medullary cavity of proximal femur was dealt with image-processing, and conus curve fitted parameter mathematical method was proposed; and at the same time, section of medullary cavity of proximal femur of 10 patients was measured manually.MAIN OUTCOME MEASURES: Computer-aided method and manual method were applied to measure the coordination at the end of extrude and the coordinate of link joint RESULTS: 10 femoral samples entered the stage of result analysis. Com puter was used to measure the coordination of the end of extrude of the section medullary cavity of proximal femur (X,Y) and the coordination of the connection point (X,Y).There was no significant difference of the measuring results between computer-aided method and manual CONCLUSION: Computer-aided imaging-processing method not only reduces the error but also can be completed by computer automatically in measuring section morphology of medually cavity in proximal femur. It is suitable for a variety of morphology measurement.

BACKGROUND: Properties of cancellous bone is significant for metabolic diseases, fracture and joint retrograde diseases.OBJECTIVE: To study the biomechanical properties of cancellous bone.DESIGN: Experimental observation based on femur specimens as the single sample.SETTING: Laboratory of Orthopaedic Biomechanics Ninth Affiliated Hospital Shanghai Second Medical University.PARTICIPANTS: The study was completed in the Laboratory of Orthopaedic Biomechanics, Shanghai Ninth People's Hospital from May to July in 2001,totally 19 male cadaveric femoral heads were selected.METHODS: Totally 19 cadeveric cancellouce bone specimens(about 30years old) from the bearing area of fresh femur head were tested by compression test.MAIN OUTCOME MEASURES: Yield load limiting stress, limiting strain, energy value and elastic modulus of specimens.RESULTS: The compressive data of cancellous bone were measured, the average value of yield load was (410.64 ± 190.29) N , limiting stress was (8.69 ± 3.75) MPa, limiting strain was (10. 84 ±6.58)%, energy value was (2.54 ± 1.89)J, modulus of elasticity was (40.77 ± 32. 12)MPa, At the early time of loading, the cancellous bone showed elastic deformation, then CONCLUSION: The trial indicates that biomechanical properties lighten the pressure of external compression.

ObjectiveTo observe and analyze the synapses developing process of newly generated connections of autologus activated Schwann cells (AASCs) in combination with fetal spinal cord cell suspension(FSCS) in the surrounding area of the spinal cord injury site.MethodsA total of 42 Wistar rats underwent unilateral ligation of the saphenous nerve.The portion of nerve tissues distal to the ligation site were harvested 1 week after operation.AASCs were isolated,cultured and purified.Spinal cord injury model produced in 42 Wistar rats on T7 by modified Allen impact method.Three days after injury,20 μl FSCS with a density of 1×105/μl prepared from pregnant rats (El4) in combination with AASCs were injected into the epicenter of the traumatized cavity.Animals were sacrificed at 2,4,6,8,10,12 weeks post transplantation.Light and electronmicroscopic studies as well as immunohistochemical assay were carried out to evaluate the graft survival,its differentation and integration with the host.ResultsIn the transplantation area,AASCs showed good growth and differentiation,and glial scarring surrounding the lesions was less.The neuroblast stretched out the terminal endings 4 weeks after implantation,followed by the presenting of the pre- and post-synaptic membrane.Eight weeks post transplantation,the dense or developed projections were observed in the pre- and post-synaptic membrane,the high electron dense substance full filled the synaptic cleft.All the spherical cleat vesicles,granular vesicles,elliptical vesicles and flattened-f type vesicles were discovered under the electron microscope.Ten weeks after injury,the axosomatic,dendrosomatic,dendro-dendritic,axoaxonic,and dendro-axonic synapses coexisted.Light microscopy showed that the graft cell grew gradually.Immunohistochemical assay showed that NF,5-HT,CGRP and GFAP positive fibers were in the graft.Synapses,glia fibers and blood brain barrier integrated each other.Conclusion1) The transplanted FSCS combined with AASCs can develop mature synapses with miscellaneous synaptic vesicles in the acute injured spinal cord.2) Co-existing indicate the possibility of synaptic connection between FSCS and host.

Objective To explore the clinical characteristics and risk factors of re-fracture in patients suffering from osteoporosis-related fractures as well as effective interventions.Methods From January 2006 to January 2008,a total of 273 patients with osteoporosis-related fracture were entered in the study,including out-patients and in-patients who were over 50 years old.The patients were divided into fracture group(n=225)and re-fracture group(n=48).The re-fracture rate was followed up for 2 years,during which 11 patients developed re-fracture.General data including age and sex,fracture types,femoral neck bone mineral density(BMD)T-scores tested by dual-energy X-rays absorptiometry(DEXA),Charlson index,timeinterval between two fractures as well as mobility skill assessment were collected and analyzed.Results The average age at the first fracture was 67.7±8.5 years vs.72.7±9.5 years for the re-fracture cases.Female accounted for 70.2% of the fracture group and 77.1% of the re-fracture group.The most common re-fracture type was vertebral fracture for the first time and femoral neck fracture for the second time during the followup.Risk factors for a second fracture in osteoporotic fractures patients include age(＞75 years,HR=1.23; ＞85years,HR=1.68),female sex(HR=1.36),prior vertebral fractures(HR=1.62),prior hip fractures(HR=1.27),BMD T-score＜-3.5(HR=1.38)and weakened motor skills(HR=1.27).The refracture rate in osteoporosis-related fractures was 4.9% followed up for 2 years.The second fracture happened 3.7 years after the first one on average.Conclusion The risks of second fracture among patients with initial brittle fracture are substantial.Mobility skill assessment is an important risk factor for osteoporosis fractures recurrence.There is adequate time between fracture and re-fracture for effective interventions to prevent or reduce the risks of refracture,especially for the old women with a vertebral or hip fracture.Medication,motor function rehabilitation and fall-down prevention training would be helpful.

Objective To construct the third-generation self-inactivating lentiviral vectors including BMP-2,BMP-4,BMP-6,BMP-7,BMP-9 and Wnt3a,then integrate them into the genome of mouse embryonic osteoblast cell,MC3T3-E1,and to explore the capability of osteogenic differentiation of individual bone morphogenetic control factor and the effective approaches to further improve the capability of osteogenic differentiation.Methods The plasmid vectors of gene expression including BMP-2,BMP-4,BMP-6,BMP-7,BMP-9 and Wnt3a were constructed,which were identified through enzyme cutting and further confirmed through sequencing.After packing pELNS-BMP-2,BMP-4,BMP-6,BMP-7,BMP-9 and Wnt3a,mouse embryonic osteoblast cell,MC3T3-E 1 was transfected,and the transfection efficiency was confirmed by GFP fluorescence imaging.The expression level of Runx2 mRNA and the transfection efficiency of individual bone morphogenetic control factor was detected by Real time PCR.Eight groups of MC3T3-E1 were dual-gene co-transfected,and the transfection efficiency was verified by GFP fluorescence imaging.ELISA was adopted to detect the expression level of BGP and ALP in MC3T3-E1culture supernatants;Real time PCR was adopted to detect the expression level of Runx2 mRNA;Western blot was adopted to detect the expression level of protein of BMP-2,BMP-4,BMP-6,BMP-7,BMP-9 and Wnt3a.Thus,the effectiveness of osteogenic differentiation of dual-gene co-transfection were evaluated.Results The recombination of lentiviruses,pELNS-BMP-2,pELNS-BMP-4,pELNS-BMP-6,pELNS-BMP-7,pELNS-BMP-9 and pELNS-Wnt3a were successfully constructed.MC3T3-E1 was successfully transfected.The expression levels of Runx2 mRNA were:BMP-2 ＞ BMP-4 ＞ BMP-9 ＞ BMP-7 ＞ Wnt3a ＞ BMP-6.Successful transfection of the dual-gene co-transfection of eight groups of MC3T3-E1 were verified by GFP fluorescence imaging.The expression level of Runx2 mRNA,the expression of BGP and ALP showed BMP-2 and BMP-7 co-transfection group was the most efficient in osteogenesis transfection.Western blot revealed thatthe protein expression of BMP-2,BMP-4,BMP-6,BMP-7,BMP-9 and Wnt3a increased after cotransfection of MC3T3-E1 by BMP-2 and BMP-7.Conclusion The third-generation lentiviral vector,pELNS can lead BMP-2,BMP-4,BMP-6,BMP-7,BMP-9 and Wnt3a into MC3T3-E1,mouse embryonic osteoblast cell,and stabilize its expression.Individual bone morphogenetic control factors can promote MC3T3-E1's differentiation to osteoblasts.The dual-gene co-transfection of BMP-2 and BMP-7 can effectively promote osteoblast conversion,which provides significant theoretical basis and technical support for remodeling of tissue engineering bone.

Objective To explore the killing effect of dielectric barrier discharge (DBD) plasma on tumor cells and to analyze the DBD-induced apoptosis mechanism.Methods Thiazolyl blue tetrazolium bromide (MTT) assay method was used to detect the killing effect of low temperature plasma on the cytotoxicity of normal spleen leukocytes and acute promyelocytic leukemia cells (LT-12) at different doses.The changes of reactive oxygen species (ROS) level were measured after plasma treatment.The cell apoptosis rate was detected by Annexin V/PI double staining at different doses.The expression of apoptosis-related genes and proteins was detected by qRT-PCR and Western Blot.Results MTT results showed that the killing effect of plasma treatment was dose-dependent and time-dependent.The cell survival rate after 8 hours of treatment decreased from 98％ to 63％ with the dose increasing from 30 s to 240 s.The survival rate decreased from 78％ (2 h) to 39％ (24 h) after the treatment with a same dose (e.g.240 s).Annexin V/PI double staining results demonstrated that the plasma effect can induce apoptosis,and the apoptosis rate was not only positively correlated with the plasma dose,but also with the post-plasma time.The longer the post-plasma time,the higher was the apoptosis rate.The apoptotic rate of the 60 s dose treatment after 12 h was 48％ that increased to 55.3％ with the dose of 120 s.The production of reactive oxygen species (ROS) detected by flow cytometry also showed a time correlation of the plasma treatment.After the plasma treatment,the ROS level immediately increased to 1.24 times,and sharply increased to 5.39 times after 20 h post-plasma.The experimental results of qRT-PCR and Western blot showed that the expression of the genes and proteins of Caspase family and Bcl-2 family was very active at 8 to 12 h post-plasma treatment.Conclusions Low-temperature plasma can effectively kill tumor cells,and apoptosis is the main mechanism of death.The molecular mechanism of apoptosis of tumor cells induced by low temperature plasma was preliminary confirmed.

This study was conducted to search the law of the parameters of medullary canal section shape in proximal femur. The methods of image-processing and taper-curve-fit mathematics were adopted in the acquisition of data and parameters. Computer-aided method and manual method were employed to measure 10 samples of section shape in proximal femur. The results showed that no significant difference was seen between the computer-aided method and manual method(P>0.05). This approach could reduce man-made errors and process mass samples automatically by computer.

This study sought to establish a set of hip prostheses for the Chinese population and improve the design guidelines for hip prostheses. 480 cadaveric adult femora were obtained for X-ray imaging. 21 geometric parameters of femora were sampled on the anteroposterior(AP) and mediolateral(ML) views of radiograph in conjunction with computer-aided image processing technology. The curves of canal of proximal femur were fitted and made statistics. Pattern recognition was used to classify these geometric parameters. The results of classification corresponded with the 10 groups of data for design. On the basis of the numerous set of data, the results and classification would serve as means and guidelines for optimizing the design of prosthetic components and so far as custom-built hip prosthetics.
Femur ; diagnostic imaging ; Hip Prosthesis ; Humans ; Image Processing, Computer-Assisted ; Pattern Recognition, Automated ; Prosthesis Design ; Radiography

A novel method for the design of hip joint prostheses based on X-ray films is introduced. Only arcs and straight-lines form figures of hip joint prostheses. Because geometrical tolerances of manufacturing hip joint prostheses matching section are usually not strict, hip joint prostheses can be manufactured without CNC machine tool. Three hip joint prostheses for three different femurs were designed through a program which was developed by the present authors. Approximate marrow cavities of these femurs were simulated according to a standard database about femur. These models of femur marrow cavities were used to verify the hip joint prostheses designed. These hip joint prostheses designed were manufactured and implanted into femurs respectively. Experimental results indicate that the novel method for the design of hip joint prostheses is practicable.
Computer-Aided Design ; Hip Joint ; diagnostic imaging ; Hip Prosthesis ; Humans ; Prosthesis Design ; methods ; Tomography, X-Ray Computed

OBJECTIVE: To explore the changes of biomechanic al properties of cortical allograft in different mechanical environments. METHODS: Cortical allograft was transplanted to each side of th e midshaft diaphyseal ulna of each one of 40 rabbits. The left transplanted allo graft underwent normal physiological load, while the right one underwent lower l oad. After animals were killed,specimens were taken for examination of bone mine ral density, bone porosity and maximal three-point-bend breaking load. RESULTS: The union strength of allograft-host bone junction wa s increased constantly; meanwhile, the internal creeping substitution led to an initial greater weakening of the cortical allograft itself and a later recovery of its strength. In comparison, the union strength of the normally loaded graft -host bone construct was significantly higher than that of the lower loaded sid e at the 8th and 16th week after transplantation. At the 16th week, there was gr eater bone strength in normally loaded graft than that in lower loaded graft. CONCLUSIONS: The internal repair can lead to initial greater we akening of cortical allograft and later gradual recovery of its strength. The ef fect of physiological load can accelerate the improvement of the biomechanical p rope rties of allograft.