BACKGROUND:During the treatment of posterolateral tibial plateau fractures through the fibular head approach,the gap between the fibular head and the lateral plateau cannot accommodate the posterior placement of a plate for all patients.OBJECTIVE:To analyze,via finite element analysis,the differences in fixation strength resulting from varying the angles and quantities of horizontal arm variable angle screws in the plate during the treatment of posterolateral tibial plateau fractures through the fibular head approach.METHODS:A finite element model was established based on CT images of the knee to ankle joints of a 30-year-old healthy adult male volunteer.The models were divided into two categories:posteriorly placed group and non-posteriorly placed group based on whether the lateral locking compression plate was posteriorly placed.The posteriorly placed group was further subdivided into groups A-D based on the offset angle of the two variable angle screws(0°,5°,10°,and 15°).The non-posteriorly placed group was subdivided into groups E and F based on offset angles(0° and 15°).Finite element analysis was used to evaluate the von Mises stress distribution,maximum von Mises stress,and compressive displacement under loads of 250,500,and 750 N,exploring the mechanical differences between the groups.RESULTS AND CONCLUSION:(1)Finite element analysis results showed that under a 750 N load,the maximum compressive displacement trend of the internal fixation device was D＜B=C=F＜A＜E.The trend for maximum von Mises stress was B＜C＜A＜D＜F＜E.The trend for maximum compressive displacement on the bone was C=D＜B＜A＜F＜E,and for maximum von Mises stress,it was B＜C＜A＜F＜D＜E.The displacement and stress trends for the six models were similar under loads ranging from 250 N to 750 N.(2)These results suggest that for posterolateral tibial plateau fractures fixed through the fibular head approach,posterior placement of the plate should aim to accommodate two screws.If only one screw can be fixed during surgery,variable angle screws should be offset in the range of 0-15° to increase the probability of securing two screws.

Immune thrombotic thrombocytopenic purpura (iTTP) is a fatal thrombotic microvascular disease closely associated with a severe deficiency of a disintegrin and metalloproteinase with thrombospondin motifs 13 (ADAMTS13). This review summarized the role of ADAMTS13 in the pathogenesis and clinical diagnosis and treatment of iTTP, as well as the detection of plasma ADAMTS13.

BACKGROUND:During the treatment of posterolateral tibial plateau fractures through the fibular head approach,the gap between the fibular head and the lateral plateau cannot accommodate the posterior placement of a plate for all patients.OBJECTIVE:To analyze,via finite element analysis,the differences in fixation strength resulting from varying the angles and quantities of horizontal arm variable angle screws in the plate during the treatment of posterolateral tibial plateau fractures through the fibular head approach.METHODS:A finite element model was established based on CT images of the knee to ankle joints of a 30-year-old healthy adult male volunteer.The models were divided into two categories:posteriorly placed group and non-posteriorly placed group based on whether the lateral locking compression plate was posteriorly placed.The posteriorly placed group was further subdivided into groups A-D based on the offset angle of the two variable angle screws(0°,5°,10°,and 15°).The non-posteriorly placed group was subdivided into groups E and F based on offset angles(0° and 15°).Finite element analysis was used to evaluate the von Mises stress distribution,maximum von Mises stress,and compressive displacement under loads of 250,500,and 750 N,exploring the mechanical differences between the groups.RESULTS AND CONCLUSION:(1)Finite element analysis results showed that under a 750 N load,the maximum compressive displacement trend of the internal fixation device was D＜B=C=F＜A＜E.The trend for maximum von Mises stress was B＜C＜A＜D＜F＜E.The trend for maximum compressive displacement on the bone was C=D＜B＜A＜F＜E,and for maximum von Mises stress,it was B＜C＜A＜F＜D＜E.The displacement and stress trends for the six models were similar under loads ranging from 250 N to 750 N.(2)These results suggest that for posterolateral tibial plateau fractures fixed through the fibular head approach,posterior placement of the plate should aim to accommodate two screws.If only one screw can be fixed during surgery,variable angle screws should be offset in the range of 0-15° to increase the probability of securing two screws.

Immune thrombotic thrombocytopenic purpura (iTTP) is a fatal thrombotic microvascular disease closely associated with a severe deficiency of a disintegrin and metalloproteinase with thrombospondin motifs 13 (ADAMTS13). This review summarized the role of ADAMTS13 in the pathogenesis and clinical diagnosis and treatment of iTTP, as well as the detection of plasma ADAMTS13.

Objective To investigate the characteristics of bone marrow megakaryocytes in patients with idiopathic thrombocytopenic purpura (ITP) complicated with positive for antinuclear antibody (ANA) but cannot be diagnosed as rheumatic immune diseases. Methods Newly diagnosed ITP patients in the First Hospital Affiliated to Sun Yat-sen University were retrospectively selected and divided into ITP1 group (ITP patients with positive ANA) and ITP2 group (ITP patients with negative rheumatic indicators). Degree of thrombocytopenia, the total number of bone marrow megakaryocytes, and the ratios of various types of megakaryocytes at the initial diagnosis were compared between the two groups. Results A total of 42 newly diagnosed ITP patients were included, with 20 cases in the ITP1 group and 22 cases in the ITP2 group. There were no significant differences in general information such as gender and age between the two groups (P>0.05). The platelet (PLT) count was (7.55±0.96)×10⁹/L in the ITP1 group, which was lower than (10.23±1.21)×10⁹/L in the ITP2 group, but there was no significant between-group difference (t=1.697, P=0.097). Compared with the ITP2 group, the total number of megakaryocytes in the ITP1 group was significantly decreased (t=3.071, P < 0.01), and the ratio of granular megakaryocytes was significantly increased while the ratio of naked nuclear megakaryocytes was significantly decreased (P < 0.05); there were no significant differences in the ratios of immature and platelet-producing megakaryocytes between the two groups (P>0.05). Conclusion Patients with ITP and positive ANA have a tendency of decreased PLT, and a more significant maturation disorder of bone marrow megakaryocytes, with a lower degree of megakaryocyte proliferation compared to patients without positive ANA. ANA may exacerbate the severity of ITP by aggravating the developmental disorder of bone marrow megakaryocytes.

Objective To investigate the inhibitory effect on human ACHN cell line and its mice xenograft by using interferon α-1b combined with cyclooxygenase-2 inhibitor and the relevant mechanism in vitro and vivo experiment .Methods ACHN cell and the xenograft mice were devided into 4 groups(IFN-α1b,NS398,IFNα-1b+NS398 and control group).The inhibitory effects were tested by CCK8(Cell Counting Kit 8)assay after AHCN were treated for 24 h and 48 h.The expression of bcl-xl and COX-2 were detected by Western blot .The vol-ume of the xenografts of ACHN cell line and testing the expression of VEGF in xenografts were measured by immunohistochemistry assay .Re-sults Both IFNα-1b and NS398 exerted inhibitory effects on ACHN and this effects showed a rising trend with a increasing concentration of drugs.The combined group was more significant than monotherapy group (P<0.05).Western blot assay showed that IFNα-1b and NS398 downregulated the expression of bcl-xl and COX-2 in ACHN.The combined group was more significant than monotherapy group (P<0.05). The combined group has the greatest inhibitory effects on the xenografts of ACHN cell line compared with monotherapy group and control group(P<0.05).The expression of VEGF in tumor was obiviously inhibited in combined group compared with monotherapy group and con -trol group (P<0.05).Conclusion IFNα-1b combined with NS398 can inhibit the proliferation of ACHN and suppress the tumor growth .