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 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 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 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 review an arthroscopic technique using suture fixation for repair of the tibial eminence fractures.Methods A review of 33 patiernts with 11 Meyers and McKeever type Ⅱ,19Ⅲand 3 Ⅳ fractures of the tibial eminence treated with arthroscopic suture fixation were conducted.Results Mean follow-up time was 7 months(range,6 to 12 months).At follow-up evaluation,the range of motion retum to their previous normal levels(rang,0°to 130°).All patients underwent X-ray examination that confirmed the fracture have been healed in 2 months except 2 cases, and pulled out fixation in 12 months.Conclusion The technique of arthroscopic internal fixation of avulsed tibial eminence fractures in 33 cases is very useful in dealing with the fractures in simple fixation,minimal trauma,quick recovery.

Objective To investigate the effects of extracellular ATP on the recovery of motor function after spinal cord injury in rats.Methods Twenty healthy adult rats were randomly divided into two groups after contusion injury was performed by the weight drop method at T10 with Allen impactor.Group A(ATP group) and group B(control group) each had ten rats.At days 1,3,7,14 and 28 after injury,the recovery of motor function after spinal cord injury in rats was assessed with modified Tarlov scores and slanting board test.Results Modified Tarlov scores and slanting board test were better in group A than in group B after spinal cord injury in rats.Significant difference was found in modified Tarlov scores and slanting board test between the two groups at days 14 and 28 after injury(P