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BACKGROUND:Prosthesis selection for total hip replacement is determined by geometrical matching with femoral medullary cavity of patients and the optimal biodynamics.It is of great significance for elevating outcomes of total hip replacement.OBJECTIVE:To evaluate the biomechanics of four groups of femoral stem prostheses matched with a femar and to get a stem whose mechanics distribution is similar to the normal femur.DESIGN:Controlled observation.SETTING:Department of Orthopaedics of Oriental Hospital Affiliated to Tongji University,Department of Orthopaedics of Changhai Hospital of Second Military Medical University of Chinese PLA,and Department of Mechanical and Power Engineering of Shanghai Jiao Tong University.MATERIALS:Experiments were performed at the Laboratory of Life Quality and Machinery Engineering of Department of Mechanical and Power Engineering of Shanghai Jiao Tong University from December 2004 to October 2005.A male volunteer aged 40 years with the normal proximal ferout(175 cm height and 78 kg weight),free from hip disease,were selected.X-ray image of the eutopic femar was shot and wrote into memory in the format of DICOM.The volunteer signed an infonned consent.The experiment was approved by Hospital Ethical Committee.No.Ⅰ prosthesis,Zimmer versys Fiber Metal Taperl 1#,No.Ⅱ prosthesis,Plus APL 2#,No.Ⅲ prosthesis,Welink Ribbed system cementless01#,and No.Ⅳprosthesis,Lima F2L 1# were used in this study.METHODS:The ezDICOM software was used to read files with DICOM format of femoral X-ray image,which was converted into files with bmp format.The image files with bmp format of the proximal femar X ray were introduced with Matlab software after regulation,and the two-dimensional contour data of femar were extracted.Prosthesis matched with the template was set in PhotoShop 7.0 software.The two-dimensional contour data of prosthetic femar were extracted in MATLAB software.The ANSYS software was used to establish the model of geometrical and two-dimensional nonlinearity finite element ncluding femur and femur-femoral stem.Stress distribution in the proximal femur was analyzed and compared by loading.MAIN OUTCOME MEASURES:Stress istribution of the proximal femur.RESULTS:Stress value and distribution of No.Ⅰ prosthesis and No.Ⅳ prosthesis in proximal femur were similar to the normal femar.Moreover,No.Ⅰ prosthesis was better than No.Ⅳ prosthesis.CONCLUSION:The biomechanics of femoral stem prostheses has been evaluated by analyzing and comparing the two-dimensional biomechanics of the femoral stem prostheses based on X-ray and template,which can offer support in optimal rosthesis selection.
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BACKGROUND: Fracture healing occurrs by two ways: healing by first intention and healing by second intention, with the latter one similar to natural healing process. It has been proved that only 37% tibial farcture can reach healing by first intention, even it is fixed with strong AO steel plate. Different materials for intramedullary fixation have different influences on callus formation and callus content in the process of fracture healing.OBJECTIVE: To explore the influences of different internal fixations on callus formation and content in the course of fracture healing analysis with X ray computer image.DESIGN: Randomized controlled trialSETTING: At the Department of Orthopeadics of Changhai Hospital Affiliated to the Second Millitary Medical University of Chinese PLA and the Experimental Animal Center of the Second Millitary Medical University of Chinese PLA.MATERIALS: This study was carried out at the Experimental Animal Center and Orthopeadic Laboratory of the Second Millitary Medical University of Chinese PLA between March 2000 and July 2001. Totally 51New Zealand rabbits were randomly selected without gender limitation and divided, accccording to intermeduallry nails, into three groups with 17 rabbits in each group: rectangle-shaped intramedullary nails (RIN), Ender's nails (END) and stainless steel plates (SPL) groupsMETHODS: Fracture models were succccesufly established on rabbits.And then intramedullary nails were fixed 2 mm below the border of left tibial and fibula without exopexy. Positve and lateral X-ray films of each operational tibia were obtained at postoperational 2,3,4,8,12 weeks.Three rabbits in each group were killed for callus observation with naked eyes, and the maximal callus diameter at different time points was measured. The X-ray films at different periods were read carefully and quanatatively analyzed with computor image analysis system (lAS). The difference was compared with the analysis of variance and SNK test.MAIN OUTCOME MEASURES: The maximal callus diameter was determined with X-ray image at different time points so as to calculate the corrssponding integral of callus grey level.RESULTS: Totally 51 rabbits were enrolled in this study, 6 missed the experiment because 4 died for diarrhea and other two has exposed bone due to local infection, and then two rabbits were derived from each group; thereby, data of 45 rabbits were subjecte to the final statistical to the epak at postoperational 8 weeks; it was the longest in RIN group of the same stage,followed by Ender group and SPL group [(11.24±0.38), (10.86±0.65), (8.12±0.36) mm at postoperatively 4 weeks; ( 13.56±0.88 ), (12.84±0.20), (10.52±0.68) mm at postoperatively 8 weeks; ( 12.66±0.65 ), ( 11.84±0.55 ), (9.68±0.27) mm at postoperatively 12 weeks]. The difference between RIN, Ender and SPL was statistically significant, but the difference between the former two was unobvigroup; at the same postoperational time point, the intergral of callus grey level was the highest in RIN group, followed by Ender group and SPL group (89.11 ± 1.05,86.42±3.12,47.28 ± 1.57 at postoperatively 4weeks;159.69 ±3.64,148.72 ±1.68,79.63 ±2.41 at postoperatively 8 weeks;192.46 ±4.96,186.53 ±1.84,107.34 ±2.37 at postoperatively 12 weeks),The difference between RIN, Ender and SPL was obvious and moreover,the difference between RIN and Ender was significant at 8th week.CONCLUSION: The callus content in RIN and Ender group were higher than that in SPL group at each postoperational time point, which benefited for fracture healing. Callus content examination is a traditional means for the judgement of fracture healing. It prossesses that properties of intuition and persicuity, reliability, simplicity and practicibility. Moreover, subjectivity could be avioided if used in combination with X-ray image analysis system, since the digital management can help judging not only callus content but also callus quality, which may provide guidance for clinical treatment.
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Objective To investigate the effects of continuous passive motion (CPM) protocols on outcomes of total knee arthroplasty. Methods Seventy-two patients who underwent total knee arthroplasty were divided into 2 groups and treated with different CPM protocols: group 1 with CPM from 0 degree to 40 degrees and increased by 10 degrees per day, while group 2 with CPM from 90 degrees to 50 degrees (early flexion) and gradually progressed to full extension over a 4-day period. The CPM was administered twice a day for 1 hour over a 7-day period. All the patients participated in the same postoperative physiotherapy program. Results Group 2 (the early flexion group) had significantly more range of motion than group 1. Conclusion The early flexion can help achieve favorable functional gain after total knee arthroplasty.
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Objective To observe effects of meshed relaxing short incisions (MRSI) on the content of endothelin (ET) in rat tension skin flap,and to investigate the mechanism of meshed relaxing short incisions(MRSI) on wound healing process of tension skin flap.Method We designed an experimental model to investigate the change of ET content caused by MRSI and observe the distribution of ET in rat skin flap tissue each period of wound healing.In the meantime,the immunohistochemistry and auto image analysis were employed.Results Our results showed:(1) ET positive immunologic reaction granules involved in small vascular endothelial cell in rat skin flap tissue increased with prolonging of time within 3 days;(2) the content of ET in MRSI group were significant lower than that of hypertension group (P< 0.05) .Conclusion The decrease of ET contents may be one of the causes that MRSI improves microcirculation of skin flap, and reduces edema and facilitates healing of skin flap.
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Objective:To analyze and compare the clinical outcomes of total knee arthroplasty with patella arthroplasty and patella replacement. Methods: From May 1999 to January 2004, 251 knees in 203 patients (45 males and 158 females; age range: 25 to 91 years, average 62.8 years) with osteoarthritis (206 knees) and rheumatoid arthritis (45 knees) were evaluated using a questionnaire during physical examination. Totally 137 knees underwent patella arthroplasty and 114 underwent patella replacement, with a mean follow-up of 28.1 months. The patients were scored using KSS Score, Feller Score and British Orthopedics Association Patient-satisfaction Score. Results: Patella arthroplasty and replacement showed no obvious difference in post-operative improvement of the knee score, knee function score, patella function score and range of flexion and extent of knee. Compared with patella replacement group, patella arthroplasty group had a higher patient satisfaction rate (P
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Objective:To summarize the 10 year clinical experience of treating tibiafibular fractures with rectangle shaped intramedullary nails(RIN). Methods:From January 1987 to December 1996, 4 682 cases (3 278 male and 1 404 female) of tibiafibular fractures from 9 hospitals were treated with RIN . Three kinds of reduction methods including open reduction, semi open reduction and closed reduction were used during operation. Results:Results showed 2 173 cases (62.89%) got excellent result, 947 got good (27.40%), 214 got moderate (6.19%), 121 got poor (3.50%). The total healing rate was 90.29%. Conclusion:RIN has excellent biological characteristics which can provide a flexible interfixation when treating tibiafibular fractures, and the operation is simple, it also can be used for severe open fractures. RIN is one of the good techniques in treating tibiafibular fractures.
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Our experiment aims to compare the effects of "energy-containing lactated Ringer's solution"(EL-RS) with those of "lactated Ringer's solution" (LRS) as an initial resuscitation fluid for the treatment of traumatic shock in rabbits. Deep shock animal models were produced in 74 adult rabbits using the method of pincers pressure and Wiggers' hemorrhagic shock method to produce crush injury of the soft tissue on the thigh and comminuted fracture of the femur. Results showed that blood pressure of the experimental group rose more rapidly than control group and the survival time of the former were longer than the later. The lowering of serum lactate and blood pH etc. showed a similar difference. It is suggested that ELRS is more efficient than LRS for the treatment of traumatic shock in rabbits.
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Vascular endothelial growth factor(VEGF) is a kind of protein facilitating the angiogenesis,which can combine with its special receptor. The 2 major functions of VEGF are:(1) accelerate the proliferation of endothelial cells,leading to the formation of new vessels;(2) up regulation of the vessels permeability.The activity of the VEGF is regulated by various factors at different levels,such as: hypoxia, oncogene,the cytokine, the intercellular matrix, etc .The biological character and role of VEGF were summarized in this article with special emphasis on VEGF function and regulation.
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Vascular endothelial growth factor (VEGF)165 cDNA were inserted into the expression plasmid pcDNA3.1 site in an antisense orientation to produce antise VEGF165 expression vector.Then electrophoresis and sequencing were carried out,the antisense vector were verified and could be used for related study of antisense gene expression.