Objective To investigate the effect of medial collateral ligament reconstruction using semitendinosus autograft.Methods A total of 12 patients with medial collateral ligament injury received knee examinations.Among them,2 had lateral meniscus injury,and received partial resection of the lateral meniscus;2 had cruciate ligament(CL) injury(anterior CL in one and posterior CL in the other),and underwent bone-ligament-bone reconstruction.Medial collateral ligament reconstruction was performed using the semitendinosus tendon autograft ingrowth in the tibial tunnel.Results Primary healing was achieved in all the cases.In 10 of them,the stability of the knee was regained in 6-month follow-up;stress X-ray examination showed that the medial joint space was smaller than the contralateral one by less than 5 mm,and the position of the interference screw was optimal.Of the 12 patients,11 achieved an active knee flexion between 0? and 120?,the other,who had fracture of the lateral condyle of the femur,had a flexion of 90?.Conclusions Semitendinosus autograft provides sufficient tension for medial collateral ligament reconstruction.The fixation of the knee and the closure of the joint capsule can be achieved by using the method.

[Objective]To investgate the expression of vascular endothelial growth factor in osteonecrosis of the femoral head during the repairing with biodegradable strontium-doped calcium polyphosphate in glucocorticoid-induced rabbits.[Method]Twenty mg/kg methylprednisolone was injected into right gluteus medius muscle at intervals of 24 hours for three times in 21 adult male Japanese white rabbits.Three rabbits were killed randomly at 2 weeks after methylpednisolone injection,both the femora and humeri were histologically examined for the presence of osteonecrosis. The remaining 18 animals with a total of 36 cylindrical 2.5?5 mm femoral head defects were created following the trapdoor procedure. Eighteen animals with femoral head bone defects were randomly divided into three groups. Group A:the defects filled with strontium-doped calcium polyphosphat,Group B:the defects filled with calcium polyphosphate and Group C:the defects filled with autologous cancellous bone alone. Roentgenographic and histological examinations were performed postoperatively. Finally,immunohistochemical analysis using monoclonal antibodies anti-VEGF was performed.[Result]No hip joint dislocation occurred. In Group A,the results of VEGF expression had a significantly difference from those in the other groups 12 weeks after operation. Most of the biodegradable strontium-doped calcium polyphosphate was resorbed and was largely replaced by newly formed trabecular bone at 12 weeks. While in Group B,a major part of defect were repaired. New formed trabecular bone in the defect was very thin. In Group C,morsellized cancellous bone was completely surrounded by fibrous and newly formed trabecular bone. [Conclusion]VEGF expression in the defect of osteonecrosis of the femoral head during the repairing with biodegradable strontium-doped calcium polyphosphate may play a role in stimulating vascular invasion and granulation tissue formation.This may be an important step toward facilitating the resorption in the osteonecrosis,thus impooring the repairing proceduce of femoral head defect.

Objective To investigate the regulatory effect of fluid shear stress(FSS) on the proliferation and differentiation of osteoblasts,as well as the expression of apoptosis-inducing factor,SIVA-1.Methods The third-passage osteoblasts were divided into five experiment groups and one control group.In the experiment groups,1.2 Pa FSS were given to the osteoblasts for 0.25,0.5,1,2,and 4 hours respectively,while the control group received no FSS.Afterwards,the cells were harvested to measure MTT value and ALP activity;mRNA level of SIVA-1 were determined by RT-PCR.Results MTT revealed that the cells proliferation markedly increased in the 0.25 h and 0.5 h experiment groups with advanced cell growth curve;whereas significantly inhibited in 1,2,and 4 h groups.The FSS also increased the ALP activity at 0.25 and 0.5 hour,especially in the 0.5 h group(2.4320?0.205 S unit/100ml,158% of the control;P

Objective To observe the therapeutic effect of arthroscopic synovectomy for tuberculous synovitis of the knee. Methods Ten patients with tuberculous synovitis received arthroscopic biopsy and synovectomy. Postoperatively, isoniazid was injected into the articular cavity, and systemic antituberculosis drugs were administrated. Results These patients received continuous passive motion (CPM) from the second postoperative day. In 9 patients, the flexion ranges of the knee were improved from 90??5? before the surgery to 120??14? after the surgery, and the extension limit of the knee, from 20??3? before the surgery to 5??1? after the surgery, with statistical significant differences ( t =6.9 and 6.3, respectively; P

[Objective]To investigate the feasibility of the dermal pluripotent stem cells in the repairing of cartilage defects.It was aimed to provide experimental basis in view of cartilage defects of expanding the repair of cartilage defects seed cells selection. [Method]Neonatal cyanotic blue rabbits were used.Dermal tissue directly isolated through mechanical method and cells through enzymatic digestion were obtained.The growth characteristics of adherent adhesion of stem cells were used to obtain high cloned cells,which were subcultured.The cell concentration of 1?106/ml was cultured with polylactic acid scaffold for one weeks,and the obtained result was implanted into full-thickness articular cartilage defects of rabbits.Thirty cyanotic blue rabbit(60 joints)for about 3~5 months were randomly divided into three groups:dermal pluripotent stem cell / scaffold polylactic acid in group A,polylactic acid scaffold in group B,controls in group C.Twenty joints for each group.The rabbits were killed by air embolization at 12 weeks,restoration organization was extracted and stained by HE and toluidine blue.According to the repairing result of cartilage defect,gross and histologic scoring was made,and analyzed by statistics.The comparison of score difference between each groups was performed statistically.[Result]Gross and histological observation demonstrated that in group A organizations had smooth surface,appeared transparent,good integration with surrounding cartilage and subchondral bone.In group B there was a tiny transparent cartilage,and the fiber cartilage repair accounted for much proportion.The surface of group C showed some defects,mainly characterized by fibrous cartilage repair.After gross and histological observations statistics score analysis was performed.Results showed that group A is the most optimal(P

Disruption of blood supply to the femoral head and subsequent hypoxia are implicated in the pathogenesis of osteonecrosis of the femoral head(ONFH),which frequently leads to the progressive collapse of the femoral head,thus causing degenerative arthritis of the hip joint.But the pathophysiology of osteonecrosis of the femoral head has not been completely elucidated.It is accepted that steroids and alcohol intake are two most common causes of ONFH.Now many theories have been proposed to decipher the etiology and pathogenesis of ONFH,including abnormal lipid metabolism,elevated intraosseous pressure,intravascular coagulation,second collision theory,etc.The purpose of this review is to summarize the etiology and pathogenesis of osteonecrosis of the femoral head.

[Objective] To investigate into the cellular mechanism of growth promotion due to shear stress by studying G1-phase events responsible for the suppression of cell transition from the G1 to S phase of the cell cycle,and to establish the most suitable physiological stress to stimulate bone formation.[Methods]The osteoblasts derived from Kunming murine's calvaria were exposed to Fliud shear stress(FSS:12 dyn/cm2)for 0,0.25,0.5,1,2,4 h,respectively.In the flow chamber,its impact on cell proliferation,differentiation and the effection of cell cycle's G1/S checkpoint were recorded.The cell proliferation was studied by MTT assay.The cell differentiation was assessed through alkaline phosphatase(ALP)activity assay.Flow-cytometry,immunofluorescence and RT-PCR techniques were used to evaluate the proportion of S phase in cell cycle,the activity of CDK2,CDK4 and the expression of E2F-1,p27mRNA,which demonstrate how FSS underlying multiple mechanisms to enhance the cell cycle progression from G1 to S phase.[Results]FSS increased proliferation and advanced the time in cell growth curve,but after 1,2,4 h,the proliferation was inhibited.The FSS also increased the ALP activity,which were significantly stimulated at 0.25 and 0.5 h after shear stress(128% and 158 % of control);but the FSS decreased ALP activity at 1,2,and 4 hs.The proportion of S phase in cell cycle raised within the early period.The S phase rate significantly increased at 0.5 h(P

[Objective]To investigate the rlpairing effect on articular cartilage defects by composite of cocultures of autogenic bone marrow-derived mesenchymal stem cells(BMSCs) and chondrocytes with allogenic fully deproteinized bone(FDB),in order to provide basis for optimizing seeding cells resources.[Method]Seeding cells were collected from two-passaged BMSCsand chondroeytes and then cocultured at the rate of 2 to 1.Full thickness articular cartilage defects in the knee joints of rabbits repaired by cocultured cells seeded into allogenic FDB were served as experimental group A,by simple FDB as control group B and by nothing as blank control group C.Repaired tissues were evaluated with macroscopic views,histological scores and immunohistochemistrical stains at 8 and 16 weeks postoperatively.[Result]Chondrocytes cocultured riched in extracellular matrix and proliferated promptly.In A regenerated tissues represented hyaline-like,smoothness and flat.In group B and C,repaired tissues were fiberous and no repaire in group C.Histological scores of experimental group A excelled group B and C with statistically significant differences(P0.05).Immunohistochemistrical stains showed that cells in the zones of repaired tissues were larger in size,arranged columnnedly,riched in type-Ⅱ collagen matrix and integrated satisfactorily with native adjacent cartilages and subchondral bones in the experimental group A at 16 weeks postoperatively.[Conclusion]Cocultures of autogenic BMSCS with chondrocytes can promote proliferation of chondrocytes and production of chondral matrix.Cocultures as seeding cells can save a number of chondrocytes,shorten culturing periods and reduce subcultured times.Cocultures embedded into FDB can repair articular cartilage defects effectively.

Objective To study the preparation method of compound tissue-engineering scaffolds of the PLA/silk fibroin and evaluate its biological features.Methods The PLA scaffolds matrix were dipped into the silk fibroin solution,then dried,and PLA/silk fibroin scaffolds were prepared.There were two groups in the experiment,one group was PLA group,and the other one was compound scaffolds group.According to ISO-10993 standard,hematolysis test,dynamic coagulation time test,cell toxicity test,stimulation test and pyrogen test were performed in two groups,and the results were compared betwen two groups.Results In the stimulation test,the two kinds of materials had equally not aroused the obvious animal skin stimulation,it showed that the experiment was in accordance with the standard.In the pyrogen test,the two scaffolds material aroused the animal temperature rising without exception under 0.2℃ and the total number of degree was under 1.0℃,therefore there was no obvious difference between two groups.In the hematolysis test,the hemolysis rates of the two scaffolds samples were smaller than 5% equally(P=0.000),which indicated that the hemolysis of the compound scaffolds was better than that of the PLA scaffolds.In the dynamic coagulation time test,the coagulation time of the compound scaffolds(37 min) was longer than that of the PLA scaffolds(26 min).The anti-coagulation ability of the compound scaffolds was better than that of the PLA scaffdds.In the cell toxicity test,the cell growth situation of the compound scaffolds group was obviously better than that of the PLA group,and at the meantime the cell toxicity of the compound scaffolds was obviously smaller than that of the PLA scaffolds.Conclusion The material of PLA/silk fibroin compound scaffolds has the advanced biological consistent compared with the simplex scaffolds.Accordingly,the PLA/silk fibroin can be used as a scaffolds matrix to be transplanted into the body.

BACKGROUND: Bone marrow mesenchymal stem cells are prospective used in cartilage tissue engineering due to easy acquire and plentiful amplification in vitro in a short term.OBJECTIVE: To summarize the application of bone marrow mesenchymal stem cells in repairing cartilage defect.RETRIEVAL STRATEGY: A computer-based online search was conducted in Pubmed for English language publications containing the key words of "marrow; mesenchymal stem cells; cartilage defect" from October 1982 to December 2006, Relevant data were also searched in China Scientific and Technological Achievement Database for Chinese language publications containing the key words of "marrow; mesenchymai stem cells; cartilage defect" from October 1982 to December 2006. There were 126Exclusion criteria: duplicated articles.LITERATURE EVALUATION: Literatures including reviews and experimental studies were mainly derived from Pubmed database and China Scientific and Technological Achievement Database.DATA SYNTHESIS: It has been proved that bone marrow mesenchymal stem cells could differentiate into cartilage in vivo.However, differentiation of cartilage phenotype in vitro was restricted by multiple factors, and the controlling mechanism is still unclear up to now. Animal experiments demonstrated that bone marrow mesenchymal stem cells could repair bone and cartilage defect. Although studies on bone marrow mesenchymal stem cells and cartilage tissue engineering have developed to a certain degree, clinical applications and evaluations, including cell marks of bone marrow mesenchymal stem cells in different differentiated stages, controls of proliferation and differentiation of bone marrow mesenchymal stem cells, and gene transfection technique, still need a further study.CONCLUSION: Animal experiments indicate that bone marrow mesenchymal stem cells can significantly repair bone and cartilage defect. Although studies on bone marrow mesenchymal stem cells and cartilage tissue engineering have developed to a certain degree, problems of bone marrow mesenchymal stem cells in basic and clinical researches still need to be solved further.