多孔β—TCP生物陶瓷植入兔股骨后的拉曼光谱

以５１４．５ｎｍ和６３２．８ｎｍ激光激发,采用显微拉曼光谱和近红外傅里叶变换拉曼光谱分别研究了磷酸三钙（β－ＴＣＰ）生物陶瓷植入兔股骨后陶瓷、界面和兔股骨的拉曼光谱。对其拉曼光谱特征频率进行了初步的归属,叙述了可见光和近红外光谱的优缺点。在植入区和界面的拉曼光谱中,磷酸钙、胶原、蛋白质和脂类的拉曼特征频率同时出现,说明除磷酸钙外,还含有胶原、蛋白质和脂类,他们是有机骨基质主要组成。实验结果表明,生     

生物陶瓷材料对大鼠再植磨牙牙髓血运重建及VEGF的影响

摘要 目的：考察iRoot BP Plus在大鼠再植磨牙牙髓血运重建的作用及对血管内皮生长因子（vascular endothelial growth factor,VEGF）的影响。方法：以60只3周龄的雄性Wistar大鼠为研究对象,随机分为3组,每组20只,分别为空白组、对照组及研究组。建立再植牙模型后,进行牙髓血运重建术,对照组采用MTA覆盖整个血凝块面,研究组使用iRoot-BP Plus,空白组不进行盖面。术后4周处死大鼠,进行影像学、免疫组化染色及VEGF基因相对表达量检测。结果：相比于空白组,对照组和研究组在影像学表现中均出现不同程度的牙根再发育,根尖增大、根尖孔变窄,感染及根尖周骨损伤范围减小,根管腔狭窄,壁增厚。其中对照组牙根尖炎症范围有一定缩小,骨组织破坏未彻底消失,根尖有异型性钙化,研究组牙根尖周炎症和骨组织破坏消失,根尖形态无明显增生及异形。相比于空白组,对照组和研究组转录因子E2相关因子2（nuclear factor erythroid-2 related factor 2,Nrf2）和碱性成纤维细胞生长因子（base fibroblast growth factor,bFGF）表达的光密度值（mean optical density,MOD）值均显著增加,相比于对照组,研究组Nrf2和bFGF表达的MOD值显著增加（P<0.05）。与空白组相比,对照组和研究组大鼠TNF-α基因相对表达量均显著降低,VEGF基因相对表达量显著升高（P<0.05）;与对照组相比,研究组大鼠TNF-α基因相对表达量均显著降低,VEGF基因相对表达量显著升高（P<0.05）。结论：iRoot-BP Plus在大鼠再植磨牙血运重建术中有良好的治疗效果,能有效促进患牙愈合。     

生物陶瓷的医学应用

介绍了生物医用材料的发展历史及国内外的研究现状,分析了生物材料之所以在世界各国近年来特别受到重视的原因,结合目前我国生物材料的研究情况,提出了今后有关该领域研究的发展方向和设想。     

生物陶瓷在组织工程中的应用

生物陶瓷材料用于修复人体硬组织历史悠久,近年来已从传统的骨填充替代材料发展到骨组织工程材料,并且逐渐从硬组织修复领域扩展到了软组织再生领域。特别是硅酸盐生物陶瓷,作为一种新型陶瓷材料,因其独特的生物学效应越来越受到研究人员的关注。大量研究表明,通过调控生物陶瓷的化学组成和表面宏微观结构不仅可以促进硬组织再生,还可促进多种软组织再生,为进一步有针对性地设计与开发新型组织工程材料提供了新思路。现结合本课题组近十年的研究,重点介绍磷酸钙及硅酸盐生物陶瓷在多种组织修复及再生中的研究进展,并从材料工程和生物学的角度对生物陶瓷的未来研究方向做了展望。     

可控多孔生物陶瓷浆料制备工艺对成品的影响

在可控多孔生物陶瓷制备技术中,浆料制备工艺对成品有着重要的影响。为了得到这具体影响,特对它研究和探讨。研究结果表明,有机泡沫微球是否预处理,加料顺序,浆料的流动性对成品有着重要的影响。     

新型人工骨移植材料

日前,荷兰特文特大学经10年努力开发,研制成功一种生物陶瓷材料,可用于骨移植手术中,促进骨细胞的再生和受损骨组织的愈合。     

生物陶瓷技术的现状与发展趋势

生物陶瓷主要应用于生物硬组织医用材料,其基础研究从1965年开始,临床研究从1975年开始.传统的生物硬组织医用材料有体骨,动物内,后来发展到采用不锈钢和塑料.但这些材料在生物体中使用效果不理想：不锈钢存在溶析、腐蚀和疲劳问题,塑料存在稳定性差和强度低的问题。1990年代初,国际上兴起了人工骨研究,即将生物陶瓷用作医用复合材料,应用于人体生物体的修复,制做人工关节、人工骨、人工牙根、听觉小骨、中耳引流管等。生物陶瓷能模仿人体骨头的成分、强度,不仅具有不锈钢塑料所具有的特性,     

可控多孔生物陶瓷制备技术中保温时间的影响研究

保温时间是可控多孔生物陶瓷制备技术的重要影响因之一。为了得到这具体影响,特对其进行了研究和探讨。研究结果表明,保温时间对孔结构、气孔率与容重、水渗透率、收缩率以及强度有着重要的影响。     

生物陶瓷护套3D打印关节填充组件的制备

通过构建双相关节填充块以达到感染控制和骨再生的双重目的.利用计算机辅助设计和低温3D打印特定几何形状的生物陶瓷护套,和携带抗生素的轴向骨石膏柱,其将表现出更强的骨修复效果.这种模块化的填充物具有增强成骨、特异性药物的控制释放和生长因子的联合递送的功能.这种方法若应用于临床中将大大减少关节置换手术的医疗费用,预期可以取得...     

Effect of cup inclination on predicted contact stress-induced volumetric wear in total hip replacement

In order to increase the lifetime of the total hip endoprosthesis, it is necessary to understand mechanisms leading to its failure. In this work, we address volumetric wear of the artificial cup, in particular the effect of its inclination with respect to the vertical. Volumetric wear was calculated by using mathematical models for resultant hip force, contact stress and penetration of the prosthesis head into the cup. Relevance of the dependence of volumetric wear on inclination of the cup (its abduction angle ?_A) was assessed by the results of 95 hips with implanted endoprosthesis. Geometrical parameters obtained from standard antero-posterior radiographs were taken as input data. Volumetric wear decreases with increasing cup abduction angle ?_A. The correlation within the population of 95 hips was statistically significant (P = 0.006). Large cup abduction angle minimises predicted volumetric wear but may increase the risk for dislocation of the artificial head from the cup in the one-legged stance. Cup abduction angle and direction of the resultant hip force may compensate each other to achieve optimal position of the cup with respect to wear and dislocation in the one-legged stance for a particular patient.     

金属大头全髋关节置换术对股骨颈骨折患者血清CRP，IL-6，TNF-α水平及髋关节功能的影响

目的:分析金属大头全髋关节置换术用于股骨颈骨折的临床评价及对功能恢复的影响。方法:选择我院2013年2月~2016年2月收治的104例股骨颈骨折患者,分为对照组与观察组,各52例。对照组予以半髋关节置换术治疗,观察组予以金属大头全髋关节置换术治疗,比较两组手术时间、术中出血量,治疗前后血清C反应蛋白(CRP)、白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α),髋关节Harris评分及术后并发症。结果:观察组手术时间、术中出血多于对照组,差异有统计学意义(P0.05),观察组疼痛率低于对照组(P0.05);两组住院时间比较无差异(P0.05);治疗后两组患者血清CRP、IL-6、TNF-α比较,差异无统计学意义(P0.05)。治疗后,观察组髋关节活动度、Harris评分、髋关节功能优于对照组(P0.05)。两组术后并发症无差异(P0.05)。结论:金属大头全髋关节置换术用于股骨颈骨折的临床效果确切,可利于功能恢复。     

The importance of femur/acetabulum cartilage in the biomechanics of the intact hip: experimental and numerical assessment

Experimental studies have been made to study and validate the biomechanics of the pair femur/acetabulum considering both structures without the presence of cartilage. The main goal of this study was to validate a numerical model of the intact hip. Numerical and experimental models of the hip joint were developed with respect to the anatomical restrictions. Both iliac and femur bones were replicated based on composite replicas. Additionally, a thin layer of silicon rubber was used for the cartilage. A three-dimensional finite element model was developed and the boundary conditions of the models were applied according to the natural physiological constrains of the joint. The loads used in both models were used just for comparison purposes. The biomechanical behaviour of the models was assessed considering the maximum and minimum principal bone strains and von Mises stress. We analysed specific biomechanical parameters in the interior of the acetabular cavity and on femur's surface head to determine the role of the cartilage of the hip joint within the load transfer mechanism. The results of the study show that the stress observed in acetabular cavity was 8.3 to 9.2 MPa. When the cartilage is considered in the joint model, the absolute values of the maximum and minimum peak strains on the femur's head surface decrease simultaneously, and the strains are more uniformly distributed on both femur and iliac surfaces. With cartilage, the cortex strains increase in the medial side of the femur. We prove that finite element models of the intact hip joint can faithfully reproduce experimental models with a small difference of 7%.     

Influence of anisotropic bone properties on the biomechanical behavior of the acetabular cup implant: a multiscale finite element study

Although the biomechanical behavior of the acetabular cup (AC) implant is determinant for the surgical success, it remains difficult to be assessed due to the multiscale and anisotropic nature of bone tissue. The aim of the present study was to investigate the influence of the anisotropic properties of peri-implant trabecular bone tissue on the biomechanical behavior of the AC implant at the macroscopic scale. Thirteen bovine trabecular bone samples were imaged using micro-computed tomography (μCT) with a resolution of 18 μm. The anisotropic biomechanical properties of each sample were determined at the scale of the centimeter based on a dedicated method using asymptotic homogenization. The material properties obtained with this multiscale approach were used as input data in a 3D finite element model to simulate the macroscopic mechanical behavior of the AC implant under different loading conditions. The largest stress and strain magnitudes were found around the equatorial rim and in the polar area of the AC implant. All macroscopic stiffness quantities were significantly correlated (R² > 0.85, p < 6.5 e-6) with BV/TV (bone volume/total volume). Moreover, the maximum value of the von Mises stress field was significantly correlated with BV/TV (R² > 0.61, p < 1.6 e-3) and was always found at the bone-implant interface. However, the mean value of the microscopic stress (at the scale of the trabeculae) decrease as a function of BV/TV for vertical and torsional loading and do not depend on BV/TV for horizontal loading. These results highlight the importance of the anisotropic properties of bone tissue.     

Sensitivity analysis of a cemented hip stem to implant position and cement mantle thickness

Patient-specific finite element models of the implanted proximal femur can be built from pre-operative computed tomography scans and post-operative X-rays. However, estimating three-dimensional positioning from two-dimensional radiographs introduces uncertainty in the implant position. Further, accurately measuring the thin cement mantle and the degree of cement–bone interdigitation from imaging data is challenging. To quantify the effect of these uncertainties in stem position and cement thickness, a sensitivity study was performed. A design-of-experiment study was implemented, simulating both gait and stair ascent. Cement mantle stresses and bone–implant interface strains were monitored. The results show that small variations in alignment affect the implant biomechanics, especially around the most proximal and most distal ends of the stem. The results suggest that implant position is more influential than cement thickness. Rotation around the medial–lateral axis is the dominant factor in the proximal zones and stem translations are the dominant factors around the distal tip.     

骨水泥型与生物型髋关节置换术治疗股骨颈骨折对术后关节疼痛的影响

目的:探讨骨水泥型与生物型髋关节置换术治疗股骨颈骨折对术后患者关节疼痛的影响。方法:回顾性分析2012年2月-2013年8月我院收治的股骨颈骨折患者的临床病历资料,按照假体类型将其分为骨水泥型髋关节置换术(A组)和生物型髋关节置换术(B组),通过Harris与分项百分制髋关节疼痛评分比较两组患者术后髋关节的疼痛情况。结果:两组患者的手术时间、术中出血量以及术后引流量比较,差异无统计学意义(P0.05),A组的住院时间短于B组,差异有统计学意义(P0.05)。A组术后3、6个月的髋关节疼痛率均低于B组,术后12、24个月则高于B组,差异有统计学意义(P0.05);经x2趋势分析,A组患者术后髋关节疼痛率随时间增加呈逐渐上升趋势,差异有统计学意义(x2=10.837,P=0.001),B组患者术后髋关节疼痛率随时间增加呈逐渐下降趋势,差异有统计学意义(x2=9.842,P=0.002)。A组患者术后3、6个月的髋关节疼痛评分高于B组,术后12、24个月则低于B组,差异有统计学意义(P0.05);A组术后3、6个月的髋关节疼痛评分高于术后12、24个月,B组3、6个月的髋关节疼痛评分低于术后12、24个月,差异有统计学意义(P0.05)。结论:骨水泥型假体缓解髋关节疼痛近期效果优于生物型假体,而生物型假体远期效果优于骨水泥型假体。