Objective To establish a 3-dimensional (3-D) finite element knee model in healthy Chinese males, to verify the validity of the model, and to analyze the biomechanics of this model under axial load, flexion moment, varus/valgus torque, and internal/external axial torque. Methods A set of consecutive transectional computerized tomography images of normal male knee joints in upright weight-bearing position was selected. With image processing and inversion technology, the 3-D finite element model of the normal knee joint was established through the software ABAQOUS/STANDARD Version-6.5.Biomechanical analysis of this model was processed under axial load, flexion moment, varus/valgus torque, and internal/external axial torque.Results A 3-D finite element model of healthy Chinese males was successfully established. The ranges of motion of varus and valgus were both small and the difference between them has no statistical significance (P>0.05). The motion of internal and external rotation of the knee took place only in flexion situation.The range of motion of external rotation was larger than that of internal rotation in the same knee (P<0.05).Conclusion The 3-D geometrical model of the knee resembles the actual knee segments. It can immitate the knee response to different loads. This model could be used for further study on knee biomechanics.

Objective To investigate the mechanisms regarding protection of doxycycline from articular cartilage cataplasis in osteoarthritis,and provide experimental evidence for prevention and cure of degenerative osteoarthropathy and for treatment of osteoarthritis.Methods (Ⅰ) Models:Sixteen New Zealand rabbits underwent right anterior cruciate ligament riesction,and fed in each cage.The animals were injected with penicillin 400 thousands IU once a day for 3 days to prevent from infection.On the fourth day after operation,the animals were compelled to use their operated knee by driving 60 minutes per day for 4 weeks.(2) Animal groups:the animals were divided into two groups.The animals in experimental group were injected into the knees with 1.33％ doxycycline 0.3 ml (total 0.4 mg),once a day for 4 weeks.Rabbits in the control group were treated under the same condition using normal saline 0.3 ml.All rabbits were fed in their own cage and not drove.The total time was 4 weeks.(3)Example collection and data analysis:Rabbits were sacrificed by aeroembolism and their knee joints were examined by gross morphology.The mRNA expressions of MMP-3 and TIMP-1 in the cartilage and synovium were analyzed by a reverse transcription polymerase chain reaction ( RT - PCR).Results For the experimental group,condyles of femur cartilage inspection revealed that 6 cases were in Grade 0 and 2 cases were in Grade 1,and whirbone cartilage inspection showed that 5 cases were in Grade 0 and 3 cases were in Grade 1.For the control group,2 cases were in Grade 0 and 6 cases were in Grade 1.The extent of articular cartilage cataplasis was significantly different mRNA expression of MMP-3 ( 1.20 ± 0.32) (experimental) and ( 1.97 ± 0.54) (compared) ( t =3.47,P＜ 0.05).The expression of MMP-3 mRNA in cartilage and synovium was significantly decreased,respectively; while the expression of TIMP-1 mRNA was significantly increased in the experimental group(3.22 ±0.42) compared to the control group( 1.90 ±0.33) ( t =6.99,P ＜ 0.01 ).Conclusions Intra-articular injections of doxycycline inhibits the articular cartilage and synovial MMP-3 mRNA expression and increases TIMP-1 mRNA expression,thereby reducing the extent of degeneration of articular cartilage.

Objective To observe the inhibition of different concentrations of curcumin on cell growth,and explore the molecular mechanism of curcumin on human osteosarcoma.Methods Curcumin of different concentrations(0,10,20 and 40?mol/L) was administered to U-2OS cells of human osteosarcoma for 12h,24h and 48h,respectively.The proliferation of U-2OS cells was measured by MTT assay.Results Curcumin significantly inhibited the proliferation of PC-3 cells in vitro in concentration-and time-dependent manners.The higher the concentration of curcumin,the stronger the inhibition was(10?mol/L,20?mol/L,40?mol/L of r=-0.9638,-0.9778 and-0.9764,respectively,P

Objective To study the clinical presentations,risk factors of delayed infection a fter AF internal fixation and find out an eff ective treatment for this complication.Methods Eight cases of delayed infection following AF internal fix ation were reviewed.Clinical sympt oms,laboratory tests and culture re ports were studied.All patients were treated with debridement,instrumentation removal and irrigation.The woun d was primary closed followed by posto perative administration of antibio tics.The specimen obtained in the op-eration was sent to bacteria culture.Results These 8patients experienced develo pment of late infection in10-27months(a mean of 18months)after the initial procedure.The cli nical presentations were variable b ut all patients reported back pain and t he development of draining sinus.Si x patients had elevated erythrocyte sedimentation rate.None had elevated white blood cell counts.After re-operation,all patients gained reli ef of back pain and the wounds were healed u p.Low-virulence skin normal organi sms were yielded in 4cases with general culture.Conclusion These late infections after AF internal fixation may have been caused by i n-traoperative contamination.The in fection affect deep soft tissue with out involving the bone.It can be suc-cessfully treated with debridement ,device removal and irrigation,primary skin closure and short-term an-tibiotics.[

Objective:To define the reference values of several salivary variables for the diagnosis of Sjgren syndrome (SS).Methods:Mixed saliva was collected by standard proceduer.Sodium,potassium concentration,sodium-potassium ratio,total value of sodium and potassium secretion per minute and pH of the saliva samples in 40 patients with SS and 40 healthy controls were measured by automatic biochemical instrument ISE900 and pH meter.The subjects were divided according to the European classification criteria for diagnosis of SS and normal controls.Independent-sample t test were used for statistic analysis.Results:The salivary concentrations of sodium,potassium and sodium-potassium ratio were significantly elevated and the tolal value of potassium per minute and pH were significantly reduced in patients with SS(P

BACKGROUND:Cam-type femoroacetabular impingement can impose elevated mechanical loading in the hip, and may eventual y result in hip osteoarthritis, while mechanical mechanism on how this deformity leads to osteoarthritis is stil unclear.
OBJECTIVE:To analyze intra-articular mechanical environment of Cam-type femoroacetabular impingement in hip joint using three-dimensional finite element method, and to further understand the features of pathological mechanics.
METHODThree-dimensional geometry models of normal and Cam-type femoroacetabular impingement joints were constructed using Mimics and Hypermesh software with the CT data of normal hip joint. These hip models were imported into LS-DYNA analysis system, then dynamic loads and motions for standing up and sitting down were applied to al joint models. Intra-articular cartilage contact pressures and stresses were analyzed in normal hip joint and hip joint with Cam-type femoroacetabular impingement.
RESULTS AND CONCLUSION:Based on CT data, models of normal hip joint and hip joint with Cam-type femoroacetabular impingement including articular cartilage for three-dimensional finite element analysis were accurately constructed. Peak contact pressures were 4.43 and 4.59 MPa at the anterosuperior region of the acetabular rim during sitting down and standing up. The peaks of Cam-type femoroacetabular impingement hip joint were 14.96 and 14.86 MPa. Peak pressures and stress concentration were found at the anterosuperior area of acetabular rim. High contact pressure at the acetabular cartilage may be the mechanical mechanism of osteoarthritis induced by Cam-type femoroacetabular impingement.

Objective To improve the efficienct of bone defect reparing,we produced a new shaped bone substitude.And we study the result from repairing rabbit radial segmental defect.Method Twenty mature rabbits were made segmental radial defect on both sides.15 received allogenic bone powder/FS/BMP in the left,and allogenic bone powder/FS in the right.5 samples received no implant in the left as control and allogenic bone powder/FS in the right.4,8,12 weeks after operation,result were assessed by gross,radiographic and histologcal examination.Result the study showed that allgonic bone powder/FS/BMP was much faster and better than allogenic bone powder/FS in repairing the defect(P<0.05),Conclusion It is suggest that allogenic bone power/fs/BMP is a kind of high bone induce ability ,shaped,and absorbable bone substitute.

Objective To investigate the relationship of uPA and uPA R protein expression in bone giant cell tumors(GCT)with their pathological grades and relapse. Methods By using Avidin biotin complex(ABC) immunohistochemistry method, monoclonal antibodies against uPA and uPA R proteins were used to measure their expression in 23 cases of GCT (including 8 cases of pathological grade Ⅰ, 10 cases of pathological grade Ⅱ and 5 cases of pathological grade Ⅲ accord to Jaffe classification). Results According to the level of these immunoreaction, over expression of uPA and uPA R were detected in 10 and 8 patients (positive rate 43.5 % and 34.8 %). In cases with relapse or not, the positive expression rate of uPA and uPA R was 66.7 %, 28.6 %, 66.7 %, 14.3 % respectively, abnormally high expression of both uPA and uPA R proteins was found in 6 cases(66.7 %). A significant correlation existed between the uPA R expression or co over expression of uPA and uPA R proteins in GCT and its relapse (P

OBJECTIVE: To explore the clinical results of rotating hinged knee systems in the treatment of complex knee diseases. METHODS: A total of 18 patients (11 males and 7 females, aged 58.7 years, ranging 34-66 years) with complex knee diseases were selected from Second Xiangya Hospital of Central South University, who underwent 20 primary knee arthroplasties (11 left and 9 right knees) using rotating hinged prosthesis from June 2003 to May 2008. These cases included 8 rheumatoid arthritis and 10 osteoarthritis, and presented 20?-30? varus or valgus deformity or 25?-40? fixed flexion deformity. Two patients underwent bilateral knee arthroplasty. Preoperatively bone loss and deformities in all cases was evaluated by AORI and X-ray. Postoperatively the clinical results were evaluated by the HSS knee rating score system. RESULTS: Knee arthroplasty was performed in all patients successfully and unilateral operative time was 95-147 minutes (average 129 minutes). The patients were followed up form 11 months to 6 years (average 4.2 years). All the knee pain was released and the deformities were corrected. The range of joint movements was up to 100?-136?. The patients could walk without assistance of walking stick. No light or deep infection, prosthesis subsidence, dislocation or fracture resorption was found. The average HSS score was 86 (78-95 scores) post-operation while 42 (25-56 scores) pre-operation. Excellent results were received in 11 cases, good in 6 cases. The rate of excellent or good was 94%. CONCLUSION: The knee arthroplasty using rotating hinged knee systems is an effective method to treat complex knee diseases such as severe extroversion or varus. It can release the knee pain and improve joint function and the quality of life.

Objective To analyse reperfusion arrhythmias in AMI patients treated by direct PCI. To investigate prevention and treatments so as to elevate operation achievement ratio.Methods One hundred and seventy six AMI patients underwent direct PCI; of the 176 patients, 56 presented reperfusion arrhythmias. Observations were made in the context of the different arrhythmias, relation between the time onset of the arrhythmias after reperfusion, relation of infarct size number of the involved vessels and the infarct size to the arrhythmias. Results PCI performed with six hours after AMI showed much higher incidence of arrhythmias than PCI performed six to twenty four hours after AMI (P0.05).Conclusions Reperfusion arrhythmias were commonly seen in AMI patients treated by direct PCI. Early prevention and detection with appropriate treatment is the key to elevate survival rate leading to a better prognosis.