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In recent decades, bone tissue engineering has made great progress in the treatment of large bone defects, among which bioprinting is one of the most important technologies. 3D bioprinting achieves precise control of the spatial structure of bone tissue engineering scaffold manufacturing by adding different materials in layers, and cells are placed into the scaffolds based on hydrogel materials to solve the uniform distribution of cells in the scaffolds. However, most biomedical materials used for 3D bioprinting are static and cannot be changed with the dynamics of the body's internal environment. 4D bioprinting combines the concept of time with 3D bioprinting and uses stimulus-responsive materials to change their shape under various stimuli to create dynamic 3D biological structures. It offers unprecedented potential for bone tissue engineering. The shape memory properties of printed structures meet the needs of personalized bone defect repair, and functional maturation procedures promote osteogenic differentiation of stem cells. In this paper, we review the commonly used 3D bioprinting methods and the mechanism of functional and morphological transformation in 3D bioprinting developed into 4D bioprinting technology by summarizing the research on bioprinting and tissue engineering at home and abroad in recent years. What's more, we introduce the application of bioprinting in the treatment of bone defects in bone tissue engineering as well as the current challenges and future prospects.
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Objective:To explore the clinical predictive effect of the preoperative ratio of C reactive protein to albumin (CAR) on perioperative delirium (POD) in geriatric patients with femoral intertrochanteric fracture.Methods:The clinical data were analyzed retrospectively of the 398 patients who had undergone surgery for femoral intertrochanteric fractures at Department of Orthopedics, Xuanwu Hospital from January 2013 to March 2016. According to the presence or absence of POD, all the patients were divided into 2 groups: a delirium group and a normal group. The 2 groups were compared in terms of general clinical data like gender, age, body mass index, blood routine, CAR, biochemical indicators, blood coagulation indicators and concomitant internal diseases. After a single factor logistic regression analysis of the general clinical data of the patients, factors with P<0.10 were introduced into the multivariate logistic binary regression model to screen out the risk factors for POD in geriatric patients with femoral intertrochanteric fracture. The receiver operating characteristic (ROC) curve was drawn to analyze the predictive value and optimal cut-off point of CAR for POD in geriatric patients with femoral intertrochanteric fracture. Results:The incidence of POD in this cohort was 14.32%(57/398). The age, C-reactive protein, CAR, platelet and probability of pulmonary infection in the delirium group were significantly higher than those in the normal group, but the hemoglobin, albumin and prealbumin in the former were significantly lower than those in the latter ( P< 0.05). The multivariate logistic binary regression analysis showed that hemoglobin ( OR=0.975, 95% CI: 0.957 to 0.993, P=0.006) and CAR( OR=53.713, 95% CI: 17.713 to 162.876, P<0.001) were risk factors for POD in geriatric patients with femoral intertrochanteric fracture. The area under ROC of CAR in predicting POD in geriatric patients with femoral intertrochanteric fracture was 0.906 (95% CI: 0.873 to 0.933, P<0.001), and the cut-off point was 2.06. When CAR>2.06, its predicted incidence of POD was 50.50%, with a sensitivity of 89.47% and a specificity of 85.34%. Conclusion:As CAR is a risk factor for POD in geriatric patients with femoral intertrochanteric fracture, it can be used as an effective indicator to predict POD.
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Total hip arthroplasty is currently an important surgical method for the treatment of hip diseases. The modular design of the head and neck taper facilitates the adjustment of limb length and femoral offset during surgery, however, complications such as wear, corrosion and looseness of the modular interface are also inevitable old problems. In recent years, with the changes in the design of prostheses, the trend that patients becomes younger and active, and the development of minimally invasive surgery, taper corrosion has again become a problem that needs to be solved and cannot be ignored, which is causing the attention of joint surgeons. There have been many studies on the complications associated with metal-on-metal prosthesis modular interfaces, such as increased metal ion level, taper corrosion and adverse local tissue reactions, while there are few studies on the complications of metal-on-polyethylene total hip arthroplasty, and metal-on-polyethylene prosthesis has similar problems such as increased local metal ion level and adverse tissue reactions caused by taper corrosion, which may also lead to complications such as prosthesis loosening, dislocation and fracture. Currently there are few reports about head and neck taper corrosion of metal-on-polyethylene prosthesis in China and there are still controversies about its manifestation and mechanism. In this paper, we summarized the above problems through literature reviewto expound the concept, research history, assessment methods, and incidence of metal-on-polyethylene prosthesistaper corrosion and the effect of material composition, diameter of the metal head, neck length, femoral offset, geometry of the taper, surgical factors, in vivo time, and patient factors on taper corrosion are analyzed. In summary, there are still many problems in the researches about the specific forming mechanism that have not been solved, thus it is very important for the prevention of taper corrosion: choosing the same material or ceramic material, avoiding overlarge diameter of the femoral head and femoral offset, avoiding too small taper degree, paying attention to the strength of tapping and cleaning of the taper are the current viable options.
ABSTRACT
Total hip arthroplasty is currently an important surgical method for the treatment of hip diseases.The modular design of the head and neck taper facilitates the adjustment of limb length and femoral offset during surgery,however,complications such as wear,corrosion and looseness of the modular interface are also inevitable old problems.In recent years,with the changes in the design of prostheses,the trend that patients becomes younger and active,and the development of minimally invasive surgery,taper corrosion has again become a problem that needs to be solved and cannot be ignored,which is causing the attention of joint surgeons.There have been many studies on the complications associated with metal-on-metal prosthesis modular interfaces,such as increased metal ion level,taper corrosion and adverse local tissue reactions,while there are few studies on the complications of metal-on-polyethylene total hip arthroplasty,and metal-on-polyethylene prosthesis has similar problems such as increased local metal ion level and adverse tissue reactions caused by taper corrosion,which may also lead to complications such as prosthesis loosening,dislocation and fracture.Currently there are few reports about head and neck taper corrosion of metal-onpolyethylene prosthesis in China and there are still controversies about its manifestation and mechanism.In this paper,we summarized the above problems through literature reviewto expound the concept,research history,assessment methods,and incidence of metal-on-polyethylene prosthesistaper corrosion and the effect of material composition,diameter of the metal head,neck length,femoral offset,geometry of the taper,surgical factors,in vivo time,and patient factors on taper corrosion are analyzed.In summary,there are still many problems in the researches about the specific forming mechanism that have not been solved,thus it is very important for the prevention of taper corrosion:choosing the same material or ceramic material,avoiding overlarge diameter of the femoral head and femoral offset,avoiding too small taper degree,paying attention to the strength of tapping and cleaning of the taper are the current viable options.
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Acute nonvariceal upper gastrointestinal bleeding (ANVUGIB)is a commonly seen gastrointestinal emergency.Rockall and Blatchford scoring system are commonly used for risk stratification in ANVUGIB.Aims:To investigate the predictive values of Rockall and Blatchford scoring system for assessing the risk of blood transfusion,surgical intervention and mortality in patients with ANVUGIB.Methods:Five hundred and ninety hospitalized patients with ANVUGIB were scored by Rockall and Blatchford scoring system,respectively.Predictive values of these two scoring systems for assessing the risk of blood transfusion,surgical intervention and mortality were assessed by area under the receiver operating characteristic (ROC)curve (AUC).Results:Rockall and Blatchford scores in patients with blood transfusion,surgical intervention and died were significantly higher than those in patients without blood transfusion,surgical intervention and survived (P <0.01 ).The AUC of Rockall scoring system for predicting blood transfusion,surgical intervention and mortality were 0.785 (95% CI:0.743-0.828,P=0.000),0.765 (95% CI:0.693-0.837,P=0.000),0.835 (95% CI:0.703-0.966,P=0.005),respectively.The AUC of Blatchford scoring system for predicting blood transfusion,surgical intervention and mortality were 0.812 (95%CI:0.775-0.848,P=0.000),0.870 (95%CI:0.811-0.930,P=0.000),0.784 (95% CI:0.614-0.954,P=0.017),respectively.Conclusions:Rockall and Blatchford scoring system have high predictive value for blood transfusion,surgical intervention and mortality in patients with ANVUGIB.Rockall scoring system is better for predicting mortality,while Blatchford scoring system is better for predicting blood transfusion and surgical intervention.
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Objective To estimate the value of fecal tumor M2-PK in the detection of colorectal adenoma and to evaluate its potential as a screening tool for colorectal adenoma.Methods Enzyme-linked immunosorbent assay (ELISA) was used to detect the fecal tumor M2-PK in stool samples of 65 patients with colorectal adenoma and 25 controls.At the same time,the peripheral blood tumor markers such as carcinoembryonic antigen (CEA),carbohydrate antigen (CA) 19-9,CA24-2 and fecal occult blood test (FOBT) were detected in the colorectal adenoma group.Results The detection value of fecal tumor M2-PK in the colorectal adenoma group showed a significant increase,compared with the control group((6.033±4.123) U/ml vs.(2.782±1.464) U/ml,t=-3.839,P=0.000).The highest detection value was found in the group where the diameter of adenoma was greater than or equal to 2 cm ((8.775±6.548) U/ml,t=9.635,P=0.034).The larger the diameter of adenoma,the higher the positive rate of fecal tumor M2-PK (85.7% vs.41.7% vs.29.6%,χ2=11.977,P=0.003).In the colorectal adenoma group,The positive detection rate of fecal tumor M2-PK was significantly higher than that of CEA,CA19-9,CA24-2 and FOBT (46.2% vs.6.2% vs.1.5% vs.1.5% vs.27.7%,?2=76.607,P=0.000).Conclusion Fecal tumor M2 pyruvate kinase has a good clinical value in the diagnosis of colorectal adenoma.
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Objective To investigate predictors of one year mortality in the elderly patients with hip fracture following poststroke hemiplegia.MethodsA retrospective study was conducted to analyze clinical data of the elderly patients who had received surgery in our hospital from January 2000 to May 2007 forhip fractures.Patients in the poststroke hemiplegia group (group A) and the hemiplegia-free group (group B)were compared in terms of general characteristics.Predictors of one year mortality in group A were analyzed statistically.Variables to be analyzed included age,gender,American Society of Anesthesiologists(ASA) rating,preoperative comorbidity,fracture type,prefracture ambulatory status and cognitive ability,hospital stay,interval from injury to surgery,anaesthetic mode and operational mode. Results Altogether 1379 patients with a mean age of 76.4 ± 7.0 years (from 65 to 99 years) were eligible for the present investigation.Of them,101 were assigned into group A.There were significant differences between the 2 groups in ASA rating,number of preoperative comorbidity,prefracture ambulatory status and cognitive ability,hospital stay and one year survival ( P ＜ 0.05).One year follow-up found 25 deaths in group A (mortality rate 24.8％ ).Multiple logistic regression analysis showed that gender ( P =0.017),ASA rating ( P=0.009),prefracture ambulatory status ( P =0.000),chroic respiraory disease ( P =0.022) and number of preoperative comorbidity ( P =0.048) were risk factors associated with the one year mortality in group A.ConclusionsEldarly hip fracture patients with hemiplegia tend to have a longer hospital stay and a higher mortality rate than those without hemiplegia.Male gender,ASA rating ≥ Grade Ⅲ,number of preoperative comorbidity ≥ 3,chronic respiratory disease and weak prefracture ambulatory status are predictors of one year mortality in the elderly patients with hip fracture following poststroke hemiplegia.
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Objective To study the curative effect of prosthetic replacement for femoral neck frac-tures at the hemiplegic extremity in the elderly with previous stroke. Methods From May 1990 to May 2000, 189 elderly patients with femoral neck fractures were treated with prosthetic replacement. 29 cases were of previous stroke with femoral neck fractures (Garden type Ⅲ and type Ⅳ) at hemiplegic extremity. 30 non-hemiplegia cases were adopted randomly as control. Two group patients were subjected to a follow-up study for 2 years and 3 months to 8 years and 2 months(average 4 years and 11 months) to compare the differences of ages, hospitalization days, operation time, blood loss, blood transfusion, complications during perioperative period and short-term complications with each other as well as the results of femoral head re-placement versus total hip replacement in treatment of hemiplegia group. Results Two group patients sur-vived during perioperative period. The ages, hospitalization days, operation time, blood loss and blood trans-fusion were of no significant difference in two groups, while complications during perioperative period were of significant difference. 5 patients died in hemiplegia group and 2 patients died in non-hemiplegia group at 11 months to 5 years follow-up. Mortalities were 17.2% and 6.7% respectively. Short-term complication rate was of no significant difference in 2 groups. In hemiplegia group, short-term complication rate of femoral head replacement were significantly higher than that of total hip replacement. Conclusion Prosthetic re-placement is reliable to treat Garden type Ⅲ and type Ⅳ of femoral neck fractures of the hemiplegic ex-tremity in the elderly with previous stroke. Complications during perioperative period are more in hemiplegia group, but short-term complications are of no significant difference in 2 groups. Mortality of hemiplegia group is higher than in non-hemiplegia group in 5 years after operation. Total hip replacement should be in-dicated in treatment of Garden type Ⅲ and type Ⅳ of femoral neck fractures of the hemiplegic extremity in the elderly with previous stroke on condition that hip muscular strength is beyond Ⅳ degree.