Objective To compare and analyze the accuracy and safety of robot-assisted and conventional freehand open approach in pedicle screw fixation using meta-analysis.Methods PubMed,Embase,Cochrane,China Biology Medicine,Wanfang and CNKI databases were searched by computer retrieval to identify the relevant literatures published before December1,2016.The qualified literatures were selected according to the preestablished the inclusion criteria and exclusion criteria,and processed for data extraction and quality evaluation.The RevMan 5.3 software was used for the meta-analysis.The relative risk (RR) and 95％ confidence interval (CI) were adopted to represent the effect differences in the dichotomous variable data.The effect difference of continuous variable data was represented by mean difference (MD) or standardized mean difference (SMD).When P＜0.05 and 95％ CI does not contain the value of 1,the difference was considered statistically significant.Results A total of 266 patients were enrolled,including 138 cases of robot-assisted group and 128 cases of conventional freehand open group,in which 1 200 screws were implanted,including 608 screws by robot-assisted system and 592 screws by conventional freehand open approach.The Gertzbein-Robbins grading criteria (grade A to C) were used.The results showed that there was no significant difference in the accuracy of pedicle screw fixation between the robotic-assisted and conventional freehand open approach according to the grading criteria,i.e.grades A (RR =1.07,95％CI:0.82,1.39,I2=46％,P=0.62),grades B (RR=l.56,95％CI:0.86,2.82,I2=0％,P=0.14) and grades C (RR=0.91,95％CI:0.32,2.55,I2=0％,P=0.85).For the two groups,the difference was no statistically significance in the complication rate (RR=0.33,95％CI:0.05,2.17,I2=0％,P=0.25),and in the revision rate (RR=0.53,95％CI:0.10,2.90,I2=0％,P=0.47).The difference was statistically significance in the overall surgical time (MD=20.90,95％CI:5.54,36.26,I2=15％,P=0.008),and in the exposure time (MD=-1.19,95％CI:-1.63,-0.75,I2=15％,P＜0.000 01).The difference was no statistically significance in the distance between screws and facet joint surfaces (SMD=-1.15,95％CI:0.79,1.51,I2=16％,P＜0.000 01).Conclusions Compared with the conventional freehand open approach,the current evidence cannot confirm that the robot-assisted system has significant advantages in the surgical accuracy of pedicle screw fixation and complication rate.The spinal surgical robot-assisted system,as a new technology,has considerable potential for further development and application in spinal surgery.

Knee osteoarthritis (KOA) is the main cause of knee pain and disability in the elderly. KOA is a complex disease that is controlled by a variety of pathogenic factors, including general physical factors such as age, gender, obesity, family history, and mechanical factors, and unfavorable mechanical factors to the knee joint, such as trauma, sports injuries, and daily routines. The prevalence of KOA is related to genetic factors. Currently, conservative treatment has limited effects to this disease, and knee joint replacement is usually associated with many complications. Mesenchymal stem cells(MSCs) were first discovered in the bone marrow and subsequently found in peripheral blood, cord blood, skeletal muscle, heart and adipose tissue, which have high plasticity and pluripotency. The discovery of MSCs provides a new method for the treatment of KOA. Due to its powerful cartilage repair and regeneration function, researchers have conducted a large number of experimental studies on the efficacy, safety and mechanism of MSCs in the treatment of KOA in recent years. In this paper, the above studies presented were systematically reviewed.

Objective To evaluate the efficacy of high tibial osteotomy(HTO) and unicompartmental knee arthroplasty(UKA) for knee unicompartmental osteoarthrits(KOA) using Meta analysis. Methods The controlled clinical trial literatures of HTO and UKA treating KOA were retrieved, the database including Chinese Biomedical Literature Database, Wanfang Data, CNKI, VIP Data, PubMed, Cochrane Library, EBSCO and Embase, and the search period was limited to the beginning of the database to July 2018. The literature was screened and evaluated, and Review Manager 5.3 software was used for Meta analysis. Results A total of 19 articles including 1359 knee joints were included. Meta analysis results showed that HTO was superior to UKA in range of motion (ROM) (P<0.05). For the indicators, including excellent rate, Lysholm score, visual analogue scale (VAS) score, complications, repair rate, blood loss, length of stay, ambulation time, Hospital for Special Surgery (HSS) score and femorotibial angle (FTA), UKA was superior to HTO (all P<0.05). There was no significant difference in the repair rate between open wedge HTO (OWHTO) and UKA in the sub-group analysis. There were no significant differences in the operation time and Tegner exercise score between HTO and UKA ( all P>0 . 05 ) . Conclusions Both HTO and UKA have their own advantages and disadvantages. It is necessary to properly choose the operation according to the patient's condition and psychological expectation.