Objective To compare the influence of autologous and allogenic bone marrow stromal cells for repairing meniscal injury in avascular zone. Methods Forty New Zealand white rabbits were evenly divided into group A and B. The bone marrow stromal cells from group A rabbits were cultured and mixed with fibrin glue, forming graft. In group A, the graft was implanted into the meniscal injury zone in one side of the knees(autograft group), and only fibrin glue in another side(fibrin glue group). In group B, the graft was implanted into one side of knees (allograft group), and nothing was implanted into contralateral knees(control group). The rabbits were sacrificed 1, 2 and 3 months after surgery, and morphological study was done. Results In the autograft group, fibrous tissue containing a great deal of fibroblast appeared in the injured zone after 1 month, a large number of chondrocytes with formation of collagens were seen after 2 months, and the injuries healed up with fibrous cartilage after 3 months. In the control group, no healing was seen until 3 months. In the fibrin glue group, fibrous tissue was seen with a few fibroblasts, forming scar healing, but no chondrocyte. In the allograft group, the morphological appearance was similar with the autograft group. However, a large number of lymphocytes were seen in reparative tissue. Conclusion Transplantation of bone marrow stromal cells can promote the healing of meniscal injury in avascular zone. Though the allograft of bone marrow stromal cells may induce rejection, its occurrence rate is lower. The allograft for repairing the meniscal injury is worthy of further study.

[Objective]To study the effects of AO double plates in internal fixation of humeral intercondylar fractures and to analyze the causes of the disfunction in elbow.[Method]From March 2001 to March 2006,21 cases (male 14, female 7) of humeral intercondylar fractures were reviewed, with an average age of 35.3 years (ranged,15～64 years).Left elbow:9 cases;right elbow:12 cases.According to AO/ASIF classification,type C1∶6,type C2∶10, and type C3∶5,2 cases of all were open fractures. Posterior operating approach of elbow: trans-olecranon osteotomy or trans-triceps-side approach and internal fixation by standard method of AO double plates were performed in all cases.The patients began the active training of elbow joint as soon as possible postoperatively.[Result]Twenty-one cases were followed up for 8～38 months and the average time was 14.8 months.Bone union was obtained in all cases.One case complicated wound infection,it recovered after 3 weeks of dressing.And 1 case complicated with radial nerve injury,which recovered with neural nutrients.According to the Cassebaum scoring system,the effects were evaluated as excellent 7,good 10,and fair 4,and the excellent-good rate was 80.9%.[Conclusion]The application of AO double plates was proved to be a good method to treat humeral intercondylar fractures at present. But the severity of the bone comminution and soft-tissue lesion, the effective fixation,earlier active exercise were the main causes that influence the functional recovery of elbow joint.

[Objective] To study the clinical significance of the changes of 100 cases C-reactive protein(CRP)values and erythrocyte sedimentation rates(ESR)in patients with primary osteoarthritis before and after total hip and total knee replacement.[Method] A prospective study was designed to observe the changes of CRP leves and ESR in patients with primary osteoarthritis before and at 1~7 days,2 weeks,1,2,3,6,12 months after total hip and total knee arthroplasty.Ninty-two cases received follow-up.There are 35 males and 57 females with average of 64.7 years,ranging from 37 to 92 years.Sixteen had cementless total hip replacement(THR),32 had hybrid THR,7 had cemented THR and 37 underwent cemented to tal knee replacement(TKR).[Result]In both groups serum CRP level increased rapidly after surgery,peaking at day 2(THR 216.7 mg/L,TKR 257.3 mg/L),and dropping gradually to pre-operative values at the end of the first month in THR patients and at the end of the second month in TKR patients.ESR peaked at day 5 and 6 respectively after operation in THR and TKR patients(THR 93.2 mm/h,TKR 95.7 mm/h),dropping to pre-operative values at the end of the third month in THR patients and at the end of the ninth month in TKR patients.[Conclusion]Serum CRP levels changed more rapidly than ESR and returned to normal more rapidly.CRP and ESR values tended to be higher in TKR than in THR patients.CRP can reflect the status of inflammation.Dynamic observation can help diagnoze early infection.

BACKGROUND:Preliminary studies have showed that vacuum sealing drainage based on wound surface dressing biomaterials is a good method to cover the wound as succedaneous peau when the soft tissuedefects along with open fracture cannot be completely repaired during the first operation. OBJECTIVE:To explore the efficacy of vacuum sealing drainage based on wound surface dressing biomaterials in repair of soft tissue defects of foot and ankle. METHODS:Fourteen patients with soft tissue defects of foot and ankle were treated using free skin graft combined with vacuum sealing drainage technique. Meanwhile, the traditional skin graft after wound dressing changes was applied in another 11 patients. The clinical outcomes were compared between two groups. RESULTS AND CONCLUSION:The transplanted skin in 10 cases of the vacuum sealing drainage group survived. The total survival rate was 71%, and surgical dressing change was applied in the left four patients to finaly cover the wound. By comparison, the transplanted skin in four cases of the traditional group survived. The total survival rate was 54%. To finish the wound, three of the left patients were turned to surgical dressing change and two of them stil needed skin graft operation once more. The total survival rate between the two groups has no statistical significance(P > 0.05). The therapeutic procedure noted that the time waiting for the secondary surgical visit, times for dressing change before the second intervention and the time for final union between the two groups were statisticaly different (P < 0.05). So the vacuum sealing drainage based on wound surface dressing biomaterials may accelerate the repair of soft tissue defects of foot and ankle when using the free skin graft operation.

BACKGROUND:Chitosanase is an enzyme for efficient and special hydrolysis of chitoan, and hence its effective and stable expression with enzymatic activity wil contribute to improving gene therapeutic effect.
OBJECTIVE: To construct a chitosanase gene for the efficient and specifical hydrolysis of chitosan, and to investigate its expression inEscherichia coli and the main influencing factors of enzymatic activity.
METHODS:According to the sequences of endo-chitosanase ofAspergilus sp. CJ22-326 provided in Genbank (EU302818), primers were designed and synthesized. The Asperguilus endo-chitosanase gene was amplified by successive extension PCR. And then the recombinant pET28a-His6-CSN was constructed and expressed in
Escherichia coli BL21. Finaly the recombinant His6-CSN fusion protein was analyzed by sodium dodecyl sulfate polyacrylamide gelelectrophoresis (SDS-PAGE), the western blot and dinitrosalicylic acid assay for detecting the enzyme activity of eluted His6-CSN fusion protein. The influence of different pH value and temperature on the enzyme activity of the recombinant chitosanase was investigated.
RESULTS AND CONCLUSION: SDS-PAGE showed that 29 kDa proteins were expressed and the western blot assay showed that His6-CSN expressed successfuly in the host. Dinitrosalicylic acid assay determined the
enzymatic activity of His6-CSN was significantly higher than that of lysozyme, but lower than that of chitosanase from Streptomyces griseus (P < 0.05). The recombinant chitosanase displayed the maximal activity at temperature of 50℃ and pH value of 6.0. There were a higher enzymatic activity remaining at pH value of 4.0-7.0 and
temperature of 30-50℃.

BACKGROUND:Chitosan is wel known as good biocompatibility and biodegradability;however, its extensive use in biomedical applications is restricted due to its poor transfection efficiency. OBJECTIVE:To prepare the polyethyleneimine-chitosan/DNA nanoparticles loading enhanced green fluorescent protein gene, and to detect their physicochemical properties and gene transfection efficiency towards chondrocytes in vitro.
METHODS:Low molecular weight polyethyleneimine was covalently linked to chitosan backbone to construct chitosan-graft-polyethyleneimine;then the chitosan-graft-polyethyleneimine was mixed with DNA nanoparticles, which loaded enhanced green fluorescent protein gene, by a complex coacervation method. The nanoparticle morphology was observed under a scanning electron microscopy. The sizes and zeta-potentials of the
nanoparticles were measured by a Marven-nano laser diffractometer. The binding capacity of plasmid DNA was evaluated by agarose gel electrophoresis analysis. The gene transfection experiments in vitro were performed towards rabbit’s chondrocytes. The gene transfection efficiency was measured with flow cytometry and under fluorescence microscope. How marked DNA entered into the nucleus of chondrocytes mediated by the nanoparticles was detected by laser scanning confocal microscopy.
RESULTS AND CONCLUSION:The prepared nanoparticles were mainly spherical, with an average size of (154.6±18.6) nm, and zeta-potential of (24.68±6.82) mV. The agarose gel electrophoresis analysis confirmed that the nanoparticles could effectively protect plasmid DNA from DNase Ⅰ-induced degradation. Gene transfection in vitro proved that the nanoparticles were efficient in transfecting rabbit’s chondrocytes and the expression of green fluorescent proteins was observed under fluorescent microscope, with a transfection efficiency of (23.80±1.74)%that was significantly higher than that of the naked plasmid DNA and chitosan/DNA nanoparticles (P<0.05). But no significant differences were observed between polyethyleneimine-chitosan/DNA nanoparticles and LipofectamineTM 2000. These findings indicate that the polyethyleneimine-chitosan/DNA nanoparticles can effectively protect plasmid DNA from nuclease degradation, and exhibit the favorable transfection ability towards articular chondrocytes.

Objective To introduce experience of using the new AO anterolateral distal tibia locking com-pression plate (LCP) for treatment of Pilon fractures. Methods Between February and August of 2009,8 closed Pi-lon fractures were treated by open reduction and internal fixation. The distal fibula was fixed with a one-third tubular plate or an recontruction plate via a straight incision posterior to the fibular crest. The distal tibia was approched by a straight incision over the ankle joint, and the fracture was stabilized using an anterolateral distal tibia LCP. Regular follow up was made to observe and evaluate the preliminary clinical outcomes. Results Seven of the 8 patients were availabe for follow up for 3 ～ 6 months (average 4.5 months). All incisions obtained primary healing, though one ex-perienced mild superficial inflammation,and none developed deep infections. Based on the Burwell and Charnley radi-ographic criteria,anatomical reduction was obtained in 5 cases,good in 1 ,and fair in 1. Among the 5 cases exceeding 5 months postsurgery,4 were evaluated as excellent and 1 us good according to Tometta' s clinically based criteria for Pilon fractures. Conclusion With good surgical timing,internal fixation with anterolateral LCP for Pilon fractures is reliable and warrants less complications.

Objective To investigate and compare the clinical effects of intraarticular injection of sodium hyaluronate and diprospan on knee osteoarthritis. Methods 94 patients with knee osteoarthritis were divided into two groups, the HA group and Cortieosteroid group. Each patient in the HA group was treated with intra-articular injection of sodium hyaluronate at 2.5 ml every week for 5 weeks, and each patient in the Corticosteroid group was treated with intra-articular injection of diprospan at 1ml on the first and fourth week. The clinical assessments included pain,joint effusion,and Lequesne Index. Assessments were done at baseline, at week 4, and week 12. Results 88 cases were followed up for 3 months. A significant decrease in VAS scores for pain and in Lequesne Index was found in both groups at week 4 when compared to baseline and there were no significant differences between the two groups. However,at 12 week improvement in pain score and Lequesne Index was found in favour of hyaluronic acid. In addition,diprospan seemed to have preferable short-term effect on patient with joint effusion. Conclusion Both intra-articular injection of sodium hyaluronate and diprospan provided clinically significant improvement in short-term and demonstrated that hyaluronic acid had a more long-term beneficial effect in patients with knee osteoarthritis.

Objective To evaluate the clinical effects of AO clavicular hook plates in treatment of dislocation of acromioclavicular joint and/or fracture of distal clavicle in comparison with traditional means. Methods A retrospective analysis was done to compare the outcomes and complications between the treatment of dislocation of acromioclavicular joint and/or the fracture of distal clavicle by AO clavicular hook plates and the treatment by conventional devices (e.g. Kirschner’s wire, wire-cerclage, bolt, et al). Results 40 cases were followed up for 12 to 20 months and the average time was 14 months. According to Lazzcano’s criterion, the rate of excellent and fine of the clinical outcomes of the 2 groups was 100%and 78.6%respectively. After statistical Chi-square test, P=0.025. Therapeutic outcomes and complications of the former were obviously better than the latter. Conclusion Since AO clavicular hook plates display advantages of rigid fixation, non-invasion into articular surface, and possibility of early functional exercise in the treatment of acromioclavicular dislocation and fractures of distal clavicle, they are worthy of recommending.

BACKGROUND: A new composite scaffold for cartilage tissue engineer ing has been employed to culture chondrocytes and overcome many limits related to traditional scaffolds, such as poor biocompatibility, inferior mechanical property, inappropriate biodegradability, and simplex structure which can not match layered structure of articular cartilage, etc. The new composite scaffolds provided a new approach for the research of cartilage tissue engineering.OBJECTIVE: To evaluate the feasibility and value of layered cylindrical collagen/hydroxyapatite (HA) composite for cartilage tissue engineering by observing how it absorbs chondrocytes and affects its cellular characteristics.DESIGN: Completely randomized design and controlled experimental study.SETTING: Department of Orthopaedics, Third Hospital Affiliated to Sun Yat-sen University, and College of Material Science, South China University of Technology.MATERIALS: The experiment was conducted at the central experimental laboratory of the Third Hospital Affiliated to Sun Yat-sen University from June to November 2004. One two-week-old male healthy New Zealand rabbit,which was bred in 20 ℃ and 40% humidity, was used in this experiment.METHODS: ①Right amount of deionized water was added into HA, collagen I solution was added to disperse HA, then carbodiimide was added in the mixture at a proportion for getting the collagen/HA composite at different ratios. Pour to the certain mould in successive layers. The upper layer was pure collagen and the bottom was pure HA. The prepared layered cylindrical collagen/HA composite was put into the ultra low temperature freezer, lyophilized, and sterilized by ethylene oxide for the following procedures. ② Chondrocytes of juvenal rabbit were isolated and multiplied in vitro, then chondrocytes were seeded onto porous collagen/HA composite scaffold and cultured. The effects of composite scaffold on chondrocytes'morphological changes, proliferation, and function were evaluated through a series of examinations such as inverted phase-contrast microscopy, histological, scanning electron microscopy and immunohistochemistry.MAIN OUTCOME MEASURES: ①Morphology of collagen/HA porousscaffold. ②The characteristics of chondrocytes cultured in vitro. ③ The chondrocytes' compatibility with the collagen/HA porous scaffold.RESULTS: ①Morphology of collagen/HA porous scaffold: Collagen/ HA was a cylindrical three-dimensional porous scaffold in layer structure with certain mechanical strength. The top layer was pure collagen, the bottom was pure HA, and the intermediate layer was collagen and HA composite.Under scanning electron microscope, the scaffold had irregular blowhole structure, the apertures were even and pores were communicated each other. The average pore diameter was about 147 μm. ②The characteristics of chondrocytes cultured in vitro: The chodrocytes that had just been isolated were spherical; rate of living cells was 95%. 24 hours later, the cells were going to attach to the wall, extend to be triangle or polygon. The cytoplasms were abundant with secretary granules inside. The cells kept on growing in monolayer and the multiply rate accelerated after passage, and chondrocytes overspreaded the culture flask in 4 days. After passaged for several times, the multiply rate decreased. In passage Ⅵ, the ability of cell division was decreased obviously, the cytomorphosis was clear. Cellular sizes were larger. Most of cells were shuttle-shape, less refracted with blur edges, which trended to age and dedifferentiate to fibroblast. ③The chondrocytes' compatibility with the collagen/HA porous scaffold: Cylindrical collagen/ HA composite scaffold in layer structure had good hydrophilicity. The chondrocytes adhered to the surface of the scaffold, proliferated and migrated toward the scaffold through the pore. Chondrocytes attached to wall of microholes of the scaffold had largely maintained a rounded morphology and could secrete the extracellular matrix on the porous scaffold.CONCLUSION: Cylindrical collagen/ HA composite scaffold in layer structure has good cellular compatibility.It is stronger in mechanical property than pure collagen, is anideal scaffold for cartilage tissue engineering.