Evidence-based medicine(EBM)is a new mode for modern medical education in orthopaedic teaching.The theory of evidence-based medicine is an essential part of clinical education for young doctors in practice,which improves their ability of thinking,scientific research and self-education,so as to enhance the students'comprehensive ability and lay sound basis for medical practice in future.

Objective To compare two kinds of strategies of preimplantation genetic diagnosis (PGD) to evaluate embryos for reciprocal and robertsonian translocation carriers. Methods A total of 152 PGD cycles for chromosomal translocation were performed from April 2012 to June 2014 , including 60 aCGH-PGD cycles using blastomere biopsy and fresh embryo transfer, and 92 SNP-PGD cycles using blastocyst biopsy and thawed embryo transfer. The diagnosis results and clinical outcome with these two kinds of strategies were compared. Results No significant difference was found in the cycles of no embryo transfer between SNP-PGD and aCGH-PGD. The normal rate in SNP-PGD was 33.8%, which was significant higher than that of aCGH-PGD. The clinical pregnancy rate per embryo transfer in SNP-PGD was higher than that in aCGH-PGD, but the misscarrage rate and embryo damage rate were lower than those in aCGH-PGD. Conclusions The PGD strategy of applying blastocyst biopsy, SNP array, embryo cryopreservation and thawed ET leads to a better clinical outcome. It may be a promising choice for future PGD treatment for carriers with chromosomal translocation.

Objective To summarize countermeasures on common problems of microendoscopic discectomy(MED). Methods Microendoscopic discectomy was performed in 104 cases of lumbar disc herniation by using the MED system(Sofamor Danek Group,USA).Frequently encountered problems during the operation were reviewed and summarized. Results Conversions to open surgery were required in 4 out of 104 cases due to bleeding or adherence.Among the rest of 100 cases,dural injury occurred in 3 cases,with 1 case accompanying leakage of cerebrospinal fluid.Of the 100 cases(115 intervertebral spaces),the average operation time was 50 min(range,30~90 min) and the average hemorrhage amount was 80 ml(range,20~400 ml) for each intervertebral space.The 100 cases were followed for 3~32 months(average,18 months).According to the Macnab criteria,the curative effects were classified as excellent in 65 cases,good in 29 cases,and fair in 6,the rate of excellent or good effects being 94.0%(94/100). Conclusions The most frequent problems during MED are bleeding and prolonged excision of the ligamenta flava.Strict adherence to technique,acquaintance with the weakness of the ligamenta flava,and familiarity with anatomic structures of the vertebral vein system and its relationship with abdominal pressure,are very important in the prevention and treatments of surgical complications.

Objective To explore whether or not the cartilage damage in the pathogenesis of pathologic synovial plicae is due to the matrix metalloproteinase. Methods The immunohistochemical method was used to detect the expression and distribution of matrix metalloproteinase-1(MMP-1) and tissue inhibitor of metalloproteinase-1(TIMP-1) in arthroscopically clarified pathologic synovial plicae and normal synovial plicae of the knee joint.Results The positive expression rate of MMP-1 and TIMP-1 had significant differences between the pathologic and normal synovial plicae(?~2=16.014,P=0.000;?~2=4.059,P=0.044).The expression of MMP-1 was positive in the synovial lining cells,monocytes,lymphocytes,endothelial cells,and chondrocytes,but negative in the normal synovial plicae.The TIMP-1 expression was only detected in the synovial lining cells and a small quantity of fibroblast cells.The immunohistochemical analysis revealed a greater number of positive cells and intensity of staining of MMP-1 than TIMP-1.Conclusions The development of pathologic synovial plicae may yield MMP-1 and TIMP-1 with unbalanced distributions,which may be the biological basis of the pathogenesis of cartilage destruction.

The application of network and multimedia technology in combination with bilingual teaching in orthopedics is explored which not only promotes the use of multimedia technology in teaching,but also enhances students' understanding ability for professional knowledge.Moreover,it can enhance students' learning interest in medical English and medical knowledge,thus promoting education effectively.

Objective To investigate the expression and significance of MMP-3 in knee joint synovium of different stage in osteoarthritis (OA) patients. Methods MMP-3 protein were detected by immunohistochemical method in knee synovial tissues from 90 OA patients (the OA group) and OA group was divided into 3 subgroups according to Kellgren and LawrenceX-ray diagnosing standards: the gradeⅠ(n = 30), gradeⅡ (n = 30) and grade Ⅲ subgroups (n = 30). 30 patients were enrolled as control group. Immunohistochemistry was used to detect the expression of MMP-3 protein in the tissue. Results The expression level of MMP-3 protein in OA group was significantly higher that in the normal synovium (P < 0.05). There existed significant difference in the expression of MMP-3 protein between the grade Ⅲ subgroup and the gradeⅠ, or Ⅱsubgroups (P < 0.05). The expression of MMP-3 protein related positively to the severity of OA (r = 0.912, P < 0.05). Conclusion The expression of MMP-3 protein related closely to the pathogenic mechanism of OA. It may serve as an important indicator of early diagnosis and the activity of OA.

Objective To evaluate the expression and clinical significance of matrix metalloproteinase 14(MMP-14) in osteoar-thritis(OA) patients in synovium and synovial fluid of knee joint .Methods Semi-quantitative RT-PCR were used to detect the ex-pression of MMP-14 mRNA in 32 case of OA (experimental group)and 26 non-OA patients(control group)synovium ;protein level expression of MMP-14 in synovial fluid were analyzed by ELISA .Results The expression of MMP-14 mRNA in experimental group synovium of knee joint was significantly increased compared with control group (P<0 .05);but the protein level of MMP-14 was low in experimental group synovial fluid compared with control group (P<0 .05) .Conclusion The expression of MMP-14 is increased in OA patients synovium and maybe promote the progress of OA directly ;the protein level of MMP-14 is decreased in OA synovial fluid ,indicated the function of MMP-14 in OA synoviocyte indirectly .

The objective of this study is to compare the normalized prediction distribution errors (NPDE) and the visual predictive check (VPC) on model evaluation under different study designs. In this study, simulation method was utilized to investigate the capability of NPDE and VPC to evaluate the models. Data from the false models were generated by biased parameter typical value or inaccurate parameter inter-individual variability after single or multiple doses with the same sampling time or multiple doses with varied sampling time, respectively. The results showed that there was no clear statistic test for VPC and it was difficult to make sense of VPC under the multiple doses with varied sampling time. However, there were corresponding statistic tests for NPDE and the factor of study design did not affect NPDE significantly. It suggested that the clinical data and model which VPC was not fit for could be evaluated by NPDE.

Objective To discuss interventional treatment technique for benign ureteral strictures. Methods A total of 19 cases with 20 benign ureteral strictures were treated with balloon dilatation and double-pigtail ureteral stent placement. Results Among 19 caces,16 were succeeded in a rate of 84.2%.The three failure cases included one of compression by aberrant vessels,one by compression of fibrous-strings and the last one due to tortuosity of the ureter.Re-examinations,by intravenous urography and B ultrasound were carried out in 16 successors,showed gradually release of hydro-nephrosis and renal function improvement.Iatrogenic foreign body ocurred in 2 cases,caused by the protruding tail of stent which had been taken out under ureteroscopy. Conclusions Interventional technique for benign ureteral strictures possesses adventages with mild injury,simple operation,and a new effective method.

Objective To investigate the factors that affecting the efficacy of arthroscopic debridement in the treatment of knee osteoar-thritis. Methods The clinical data of patients with knee osteoarthritis treated with arthroscopic debridement in our hospital from January 2009 to December 2013 was retrospectively analyzed,and the treatment effect was evaluated by Lysholm score. The factors that may affect the efficacy were selected to make a single factor analysis,and then made a multiple logistic regression analysis with the factors which were of sta-tistical significance through single factor analysis. Results Single factor analysis showed that age,course of disease,body mass index,psycho-logical factor,preoperative VAS score,preoperative Kellgren-Lawrence grade,preoperative Lysholm score and postoperative rehabilitation exer-cise were the factors that affected the efficacy of knee arthroscopy in the treatment of knee osteoarthritis,and the difference between the two groups was statistically significant. Further multivariate analysis showed that high body mass index,high preoperative VAS pain score,low Ly-sholm score,high psychological expectations and high preoperative Kellgren-Lawrence grading were expected to be the independent risk fac-tors of knee arthroscopy in the treatment of knee osteoarthritis. Strict compliance with the postoperative rehabilitation exercise was the protect factor. Conclusion High body mass index,high preoperative VAS pain score,low preoperative Lysholm score,high preoperative Kellgren-Lawrence grading,and high psychological expectations were expected to reduce the effect of surgery,while strict compliance with the postoper-ative rehabilitation exercise can improve the curative effect.