BACKGROUND:Spinal surgery requires a relatively high accuracy. At present, the study of pedicle screw fixation is more focused on the safety and stability, but the premise is the safe and effective screw placement. Selection of the insertion point is the key to success.
OBJECTIVE:To analyze stress distribution of different pedicle screw implantation methods for thoracolumbar fractures by using finite element analysis.
METHODS:T9-L3 segments of a thoracolumbar burst fractures patient were scanned in the Department of Orthopedics, Zhaoqing City First People’s Hospital in January 2015. 616 CT Dicom images were obtained and introduced into engineering software. Finite element geometric model was established. Posterior approach orthopedic surgery was simulated. Stress distribution after pedicle screw fixation for thoracolumbar fractures was analyzed.
RESULTS AND CONCLUSION:(1) The three-dimensional motion range of the fixation with six screws and two rods was small in anteflexion, lateral bending, and axial rotation, followed by five screws and two rods by posterior approach (single right vertebral fixation). The motion range of the fixation with four screws and two rods was biggest, but biomechanical stability was poorest. (2) In different fixation models, upper screw stress was larger in anteflexion than other states in the fixation with four screws and two rods by posterior trans-traumatic-vertebra, four screws and two rods by posterior injured vertebra, six screws and two rods by posterior injured vertebra, five screws and two rods by posterior approach (single right injured vertebra) and six screws and two rods by posterior approach (upper injured vertebra), followed by left axial rotation and right axial rotation. Significant differences in screw stress were found in different motion states (P < 0.05). (3) In different fixation modes, the stress ratio of upper and lower screws was significantly larger in the fixation with four screws and two rods by posterior trans-traumatic-vertebra, four screws and two rods by posterior injured vertebra, six screws and two rods by posterior injured vertebra, five screws and two rods by posterior approach (single right injured vertebra) and six screws and two rods by posterior approach (upper injured vertebra) than other motion states (P < 0.05), followed by right axial rotation and right lateral bending. Significant differences in stress ratio of upper and lower screws were detectable in different motion states (P < 0.05). (4) Results suggested that finite element analysis could better simulate complex spine mechanical system, accurately reflect the stress distribution of spinal pedicle screw model, and provide the basis for making pedicle screw program.

Objective To study the expressions of YKL-40 and IL-1β in the cartilage of knee osteoarthritis(KOA),and analysis the possible relationship between YKL-40,IL-1β in KOA.Methods Thirty-eight patients diagnosed with KOA were selected in this hospital as observation group.Then select 30 articular cartilage cases in the same period due to knee injury knee joint examina tion or treatment of knee joint fracture surgery patients,referred to as the control group.According to KOA radiation and arthroscopic grading standards,the observation group was divided into 16 cases of mild group,10 cases of moderate group,11 cases of severe groups.Compare the expression levels of all patients including YKL-40,interleukin-1β (IL-1β),IL 6,tumor necrosis factor-α (TNF-α),while recording Mankin score and cell mortality.Results Expression of YKL 40,IL-1β,IL-6,TNFα,Mankin scores and rate of cell death about observation group were significantly higher than control group,the indicators above in mild,moderate,severe group showed a trend of rising(all P＜0.05).And the expression levels of YKL-40 and IL-1β were significantly positive correlation (r=0.738,P=0.000).In addition, The expression levels of YKL-40 had relation with IL 6 (r=0.819,P=0.000),TNF-α (r=0.871,P=0.000) and Mankin score (r=0.832,P 0.000),cells mortality deposit (r=0.832,P=0.000).Conclusion Expression levels of YKL-40 and IL-1β were significantly increased in cartilage of knee osteoarthritis patients,and there showed a significant positive correlation between YKL-40 and IL-1β.

With the increasing cost of drug development and clinical trials, it is of great value to make full use of all kinds of data to improve the efficiency of drug development and to provide valid information for medication guidelines. Model-based meta-analysis (MBMA) combines mathematical models with meta-analysis to integrate information from multiple sources (preclinical and clinical data, etc.) and multiple dimensions (targets/mechanisms, pharmacokinetics/pharmacodynamics, diseases/indications, populations, regimens, biomarkers/efficacy/safety, etc.), which not only provides decision-making for all key points of drug development, but also provides effective information for rational drug use and cost-effectiveness analysis. The classical meta-analysis requires high homogeneity of the data, while MBMA can combine and analyze the heterogeneous data of different doses, different time courses, and different populations through modeling, so as to quantify the dose-effect relationship, time-effect relationship, and the relevant impact factors, and thus the efficacy or safety features at the level of dose, time and covariable that have not been involved in previous studies. Although the modeling and simulation methods of MBMA are similar to population pharmacokinetics/pharmacodynamics (Pop PK/PD), compared with Pop PK/PD, the advantage of MBMA is that it can make full use of literature data, which not only improves the strength of evidence, but also can answer the questions that have not been proved or can not be answered by a single study. At present, MBMA has become one of the important methods in the strategy of model-informed drug development (MIDD). This paper will focus on the application value, data analysis plan, data acquisition and processing, data analysis and reporting of MBMA, in order to provide reference for the application of MBMA in drug development and clinical practice.

OBJECTIVE To understand the safety of Ilaprazole sodium for injection in clinical practice. METHODS From Jan. 1st 2019 to Feb. 29th 2020， the data of 3 926 valid hospitalized patients receiving Ilaprazole sodium for injection were collected prospectively from 5 third-level hospitals through CHPS， and the post-marketing safety analysis was performed by using retrospective multicenter single cohort study. At the same time， a nested case-control study （the ratio of trial group and control group was 1∶4） was used to confirm the baseline stability of this study cohort and the correlation between adverse reactions and Ilaprazole sodium for injection. RESULTS Among 3 926 patients， 3 patients experienced 5 adverse drug events after using Ilaprazole sodium for injection， with the incidence of 0.076%. There was no serious adverse event， and the occurrence time was 2 days after medication； adverse drug events mainly include elevated liver function indicators （alanine transaminase， aspartate transaminase， total bilirubin）， which were mild and untreated， and all adverse drug events were improved. The results of the nested case-control study showed that the trial group and the control group belonged to the same background baseline， and the occurrence of adverse drug events was more closely related to Ilaprazole sodium for injection. CONCLUSIONS The overall safety of Ilaprazole sodium for injection is relatively high， and the occurrence of adverse events is more related to it.