骨水泥强化椎弓根螺钉在骨质疏松性胸腰椎中的生物力学进展

椎弓根螺钉内固定系统为治疗骨质疏松性胸腰椎退行性疾病的主要装置。然而,骨密度的严重丢失造成骨质疏松性椎体对椎弓根螺钉的固定强度下降,内固定失败的发生率显著增加。骨水泥强化椎弓根螺钉技术是一种改善骨质疏松性胸腰椎术后内固定生物力学稳定性的有效方法,大量研究证明其能显著增加椎弓根螺钉的固定强度,但存在骨水泥渗漏等风险。本文从骨水泥强化椎弓根螺钉技术展开分析,对骨水泥强化椎弓根螺钉的适应证、骨水泥强化椎弓根螺钉的生物力学变化、骨水泥增强材料、注入体积及分布进行介绍,并对新型骨水泥材料及螺钉设计做了展望。     

模拟股骨置入人工关节股骨黏弹性实验研究

目的测量正常对照组股骨和以生物学和骨水泥固定置入人工关节组股骨标本压缩载荷一位移数据,为临床提供生物力学参数.方法利用电子万能试验机对正常对照组、股骨置入人工关节骨水泥固定组、股骨置入人工关节生物学固定组标本进行压缩和黏弹性实验研究.结果得出了在压缩状态下各组标本应力松弛、蠕变数据和曲线,并得出了各组标本的归一化应力松弛函数,归一化蠕变函数及曲线.结论骨水泥固定组纵向压缩位移比生物学固定小,说明骨水泥固定有较好的稳定性.人工关节置入股骨后,应力松弛、蠕变量均降低.骨水泥固定组较生物学固定组应力松弛、蠕变量大,其应力松弛、蠕变量丢失小,有利于稳定.     

丙烯酸基骨水泥的临床应用新进展

丙烯酸基骨水泥固定植入假体仍是目前临床最常用的方法之一。骨水泥的生物相容性较差,与骨组织界面不能形成良好的生物结合而导致假体松动等,究其原因可能是单体的聚合热、残余单体的细胞毒性及固化后的结构缺陷等所致。文章简要分析了目前骨水泥的研究应用现状,包括丙烯酸单体的改性、助剂的功能化及其固化方式的优选等。在改善生物相容性方面,目前的研究热点是磷酸钙盐的复合或掺杂等。为了保证改性后的骨水泥的强度,利用碳纤维复合增强的研究效果也非常理想。其次,还结合目前临床使用骨水泥的特点,对骨水泥在临床使用过程中应注意的问题提出了一些建议,包括聚合反应热对组织的损伤,单体残留量引发的副作用,固化过程中体积收缩及其力学性能引发的植入体松动等。     

模拟股骨置入人工关节扭转与应力松弛蠕变的实验研究

研究了在相同扭矩作用下,正常组股骨和以生物学和骨水泥固定置入人工关节组股骨标本扭转角度,还对正常股骨、生物学固定股骨和骨水泥固定股骨进行应力松弛、蠕变实验,为临床提供生物力学参数。以电子万能试验机对正常对照组、股骨置入人工关节骨水泥固定组、股骨置入人工关节生物学固定组标本进行扭转和粘弹性实验研究。得出了各组标本在相同扭矩下的扭转角度及悬臂弯曲状态下,正常组和置入人工关节组标本应力松弛、蠕变数据和曲线。对实验数据进行归一化处理,得出了正常组和置入人工关节组标本的归一化应力松弛函数,归一化蠕变函数及曲线。表明:骨水泥固定组扭转角比生物学固定组小,说明骨水泥固定有较好的稳定性,其应力松弛、蠕变量丢失小。骨水泥固定组较生物学固定组3600s应力松弛、蠕变量大。     

骨质疏松患者骨水泥强化内固定系统的生物力学特征

背景：进行椎间融合手术患者伴有骨质疏松症的比例较高,骨质疏松症会对钉棒系统固定效果造成不良影响,如螺钉松动率上升、椎间融合手术失败等,骨水泥钉道强化手术有力改善了这一问题。目的：通过有限元方法比较低骨密度情况下不同骨水泥钉道强化固定后腰椎的生物力学变化。方法：依据提取CT图像建立L4-5椎体功能单元人体有限元模型,设置所有椎体骨材料为骨质疏松状态,分别建立无骨水泥钉道强化、全部骨水泥钉道强化、L4椎体骨水泥钉道强化、单侧骨水泥钉道强化、交叉骨水泥钉道强化模型,L5节段下表面固定,L4节段上表面施加500 N的垂直向下的载荷及7.5 N·m的力矩,检测钉棒系统、椎体钉道及骨水泥团的von-Mises应力。结果与结论：(1)相较于无骨水泥钉道固定组,骨水泥强化各组对于钉棒系统的von-Mises应力影响十分微小;(2)骨水泥强化各组钉道von-Mises应力在整体上小于无骨水泥钉道固定组,其中较为显著的为全部骨水泥钉道强化组;与全部骨水泥强化组效果相近的是交叉骨水泥强化组,单侧骨水泥固定组钉道von-Mises应力下降幅度次于交叉骨水泥固定组,L4椎体骨水泥钉道强化组对于钉道von-Mis...     

表层多孔性移植体的生物固定

表层多孔性移植体是一种不使用骨水泥固定的骨科移值体。本文综述了表层多孔性移植体生物固定技术,包括表层多孔性移植体的设计;表层多孔性移体全髋置换、全膝置换的临床结果;不用骨水泥固定的表层多孔性移植体的组织学分析。     

硫酸钙骨水泥增强椎弓根螺钉置入骨质疏松椎体的瞬时稳定性

背景：由于内固定在骨质疏松骨上锚着力较差影响了其稳定性,因此需要新的固定方法,使用骨水泥或骨替代物增强内固定技术可以较好地解决这个问题。 目的：评价硫酸钙骨水泥增强的椎弓根螺钉置入骨质疏松椎体后的瞬时稳定性。 方法：选取新鲜小牛脊柱椎体,测量骨密度后,随机分为4组：①正常椎体椎弓根螺钉内固定组。②正常椎体椎弓根螺钉+硫酸钙骨水泥增强内固定组。③骨质疏松椎体椎弓根螺钉内固定组。④骨质疏松椎体椎弓根螺钉+硫酸钙骨水泥增强内固定组。将相同规格的椎弓根螺钉拧入测试椎体的椎弓根,测试其即刻最大轴向拔出力和最大破坏功耗,以评价硫酸钙骨水泥增强椎弓根螺钉的瞬时稳定性。 结果与结论：骨质疏松椎体较正常椎体的螺钉最大拔出力、最大破坏功耗明显减少(P < 0.05),而二者分别以骨水泥增强后的螺钉最大拔出力、最大破坏功耗明显增加(P < 0.05);正常组和骨质疏松组以骨水泥增强后螺钉的最大拔出力、最大破坏功耗相当。提示硫酸钙骨水泥增强后可以增加内固定螺钉的瞬时稳定性,硫酸钙骨水泥可以应用于骨质疏松患者骨折内固定的增强,具有较好的临床应用前景。中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程全文链接：     

骨水泥强化动力髋固定效果的生物力学研究

目的：研究A2型股骨转子间骨折动力髋螺钉（DHS）固定加骨水泥强化对内固定生物力学影响。方法：24对成年男性防腐股骨上段标本，制造A2型股骨转子间骨折，采用4孔DHS固定。每对股骨以左侧为非强化组，右侧为强化组，股骨头髓腔钉道填塞骨水泥。标本进行弯曲强度，扭转强度及破坏试验。测量骨折位移，转角及最大加载力。结果：强化组和非强化组在弯曲强度，扭转强度及最大加载力有显著差异（P〈0．05），有统计学意义。相对于非强化组，骨水泥强化后弯曲强度提高148％，扭转强度提高96％，最大加载力提高67％。结论：骨水泥强化有效地增加DHS固定强度，整体提高骨折稳定性，减少内固定失败的可能性。     

骨水泥填塞动力髋螺钉主钉孔:抗弯曲和抗扭转强度

目的:评价髋关节后侧入路加骨水泥填塞后内侧支撑植骨治疗转子间骨折的临床效果。方法:应用计算机检索Science Direct数据库、Ei数据库1960-01/2009-10期间的相关文章,检索词为"bone cement,Intertrochanteric fracture",并限定文章语言种类为English。同时计算机检索中国期刊全文数据库、中国生物医学文献数据库等1994-01/2009-10期间的相关文章,检索词为"转子间骨折,髋内翻,髋关节后侧入路,主钉孔植入骨水泥",并限定文章语言种类为中文。此外还手工查阅相关专著数部。纳入有关股骨转子间骨折治疗方式研究,骨水泥治疗股骨转子间骨折的基础与临床实验。结果:股骨转子间骨折手术治疗方法都为外侧或前侧入路行动力髋钢板系统、动力髋螺钉、股骨近端髓内钉常规内固定。动力髋螺钉是治疗股骨转子间骨折的标准内固定,具有较强的抗旋转功能,符合生物力学要求。但螺钉松动、拔出和断裂等并发症发生率较高。采用骨水泥强化松质骨钉道后,骨水泥强化不仅增加螺钉把持力,有利于尾钉加压;同时也扩大了骨-钉接触界面,应力被分散传递至更大的钉-骨界面区域,明显提高动力髋螺钉固定的抗弯曲和抗扭转强度,整体提高骨折稳定性。骨水泥的强化机制在于通过充填于骨小梁闯隙与周围松质骨微观交锁,形成松质骨-骨水泥-螺钉的整体结构。结论:使用骨水泥填塞动力髋螺钉,可明显增强动力髋螺钉固定的抗弯曲和抗扭转强度,整体提高骨折稳定性。     

骨水泥结合钢板固定对猪股骨远端不同大小骨缺损的生物力学研究

目的 探讨研究钢板、骨水泥对股骨远端不同骨缺损的生物力学影响,为临床合理选择修复股骨远端骨缺损的手术方法提供生物力学依据.方法 将50根猪股骨随机分为10组,M组为正常股骨,D1、C1、P1组为1/4骨缺损,D2、C2、P2组为2/4骨缺损,D3、C3、P3组为3/4骨缺损.D1、D2、D3组不重建,C1、C2、C3组单纯骨水泥填充重建,P1、P2、P3组骨水泥填充联合钢板固定重建.对各组行生物力学压缩试验.结果 骨水泥填充修复1/4骨缺损组与骨水泥填充联合钢板固定修复1/4骨缺损组差异无统计学意义(P=0.421),骨水泥填充修复2/4骨缺损组与骨水泥填充联合钢板固定修复2/4骨缺损组有显著差异(P=0.008)及骨水泥填充修复3/4骨缺损组与骨水泥填充联合钢板固定修复3/4骨缺损组有显著差异(P=0.023).结论 骨水泥填充修复股骨远端1/4骨缺损无需钢板固定,骨水泥填充修复股骨远端2/4骨缺损及其以上骨缺损需钢板固定.     

Frozen delivery of brushite calcium phosphate cements

Calcium phosphate cements typically harden following the combination of a calcium phosphate powder component with an aqueous solution to form a matrix consisting of hydroxyapatite or brushite. The mixing process can be very important to the mechanical properties exhibited by cement materials and consequently when used clinically, since they are usually hand-mixed their mechanical properties are prone to operator-induced variability. It is possible to reduce this variability by pre-mixing the cement, e.g. by replacing the aqueous liquid component with non-reactive glycerol. Here, for the first time, we report the formation of three different pre-mixed brushite cement formulations formed by freezing the cement pastes following combination of the powder and liquid components. When frozen and stored at -80 degrees C or less, significant degradation in compression strength did not occur for the duration of the study (28 days). Interestingly, in the case of the brushite cement formed from the combination of beta-tricalcium phosphate with 2 M orthophosphoric acid solution, freezing the cement paste had the effect of increasing mean compressive strength fivefold (from 4 to 20 MPa). The increase in compression strength was accompanied by a reduction in the setting rate of the cement. As no differences in porosity or degree of reaction were observed, strength improvement was attributed to a modification of crystal morphology and a reduction in damage caused to the cement matrix during manipulation.     

α-磷酸三钙/HA晶须/羧甲基壳聚糖-明胶复合增强多孔骨水泥的制备研究

为研究羟基磷灰石(HA)晶须和羧甲基壳聚糖-明胶(CMC-Gel)对多孔磷酸钙骨水泥(CPC)力学性能的影响,将α-磷酸三钙(α-TCP)粉、HA晶须和致孔剂L-谷氨酸钠按一定的质量比进行混合,加入调和液制备成α-TCP/HA晶须复合多孔骨水泥,然后将其浸润到一系列不同CMC和Gel质量比的溶液中以制备α-TCP/HA晶须/CMC-Gel复合增强多孔骨水泥,对其进行抗压强度测试和扫描电镜观察。结果显示,当HA晶须含量为4%,未添加CMC和Gel时,α-TCP/HA晶须复合多孔骨水泥的抗压强度达到2.57MPa,与未复合HA晶须的骨水泥相比提高了81%;当CMC和Gel的质量比为50∶50时,α-TCP/HA晶须/CMC-Gel复合多孔骨水泥的抗压强度达到最大值3.34MPa,与单纯的多孔α-TCP骨水泥相比提高了135%,同时韧性也有较大改善。     

Comparison of the mechanical properties of Simplex P, Zimmer Regular, and LVC bone cements

The mechanical properties of the three cement preparations most widely used in the United States were compared by conducting tensile and fatigue tests on Simplex P, LVC, and Zimmer Regular bone cements. Specimens of all three cement preparations were prepared for mechanical testing with and without centrifugation of the cement immediately after mixing. Although the results of the tensile testing revealed a few specific instances of significant differences in the tensile properties of the three cement preparations, there was no consistent evidence that one cement was superior in tension to the others. However, the fatigue properties of Simplex P were consistently and significantly superior to the fatigue properties of both LVC and Zimmer Regular bone cements. Centrifugation of the cement immediately after mixing significantly improved both the tensile and fatigue properties of all three bone cements. However, the fatigue strength of centrifuged Simplex P was substantially and significantly superior to the fatigue strength of the centrifuged LVC and Zimmer Regular bone cements. Since in total joint replacements bone cement is subjected to cyclic loading, these data suggest that centrifuged Simplex P is a preferable bone cement to LVC and to Zimmer Regular cement with or without centrifugation.     

Influence of mixing techniques on the physical properties of acrylic bone cement

Palacos R bone cement was prepared using three commercially available mixing techniques, first generation, second generation and third generation, to determine the mechanical properties and porosity contents of the bone cement. The compressive strengths, bending strengths and flexural moduli were expressed as a function of void content. The volume of pores within the cement structure was found to be a contributing factor to the physical properties of acrylic bone cement. The lower the volume of voids in the cement the better the compressive and flexural properties, hence stronger bone cement. It was found that the best results were obtained from cement that had been mixed using the Mitab Optivac or Summit HiVac Syringe systems at a reduced pressure level of between -72 and -86 kPa below atmospheric pressure, resulting in cement of porosity 1.44-3.17%; compressive strength 74-81 MPa; flexural modulus 2.54-2.60 GPa; and flexural strength 65-73 MPa.     

注射型丙烯酸树脂骨水泥的实验研究及生物学性能评价

目的对注射型丙烯酸树脂骨水泥的制备进行研究，评价其物理性能和生物学性能。方法制备出注射型丙烯酸树脂骨水泥，按照国际标准ISO5833对其凝固时间、最高温度、抗压强度、抗弯强度、抗弯模量等物理性能进行检测，并与进口骨水泥进行对比，按照国家标准对骨水泥的生物学性能进行评价。结果所制备的骨水泥物理性能符合国际标准ISO5833的要求，各项生物学性能实验合格。结论所研究的注射型骨水泥物理性能符合国际标准的要求，具有良好的生物相容性。     

骨水泥不同时相负载抗生素

背景：在人工关节置换中,骨水泥与何种抗生素配伍能起到有效预防和治疗置换后感染目前还存在争议。 目的：观察抗生素骨水泥中不同抗生素及不同混合方法对动物体内抗生素释放特性以及骨水泥力学性能的影响。 方法：36只大白兔随机抽签法分为6组,3个实验组在骨水泥固相与液相混合后分别加入2 g硫酸庆大霉素、1 g万古霉素、1.5 g头孢呋辛钠,制成负载抗生素的骨水泥,置于实验兔体内。3个对照组分别在40 g骨水泥固相与液相混合前加入2 g硫酸庆大霉素粉剂、1 g万古霉素粉剂、1.5 g头孢呋辛钠。 结果与结论：3种抗生素在兔体内持续平均释放时间均在31 d以上,骨水泥固相与液相混合后加入抗生素的3组抗生素洗提总量分别高于混合前加入抗生素的3组(P < 0.05),混合后加入万古霉素组的洗提总量高于其他各组(P < 0.05)。各组抗生素骨水泥的力学性能均优于ISO 5833国际标准,组间差异无显著性意义。提示抗生素能有效从骨水泥中释放,骨水泥中加入1.0~2.0 g抗生素不影响骨水泥的机械强度;万古霉素的洗提效果较好;骨水泥固相与液相混合后加入抗生素的混合方法更有利于抗生素的释出。     

Brushite-collagen composites for bone regeneration

Brushite-based biomaterials are of special interest in bone regeneration due to their biocompatibility and biodegradability; on the other hand, collagen is a well-known osteoconductive biomaterial. In the present study a new brushite-collagen composite biomaterial is reported. This new biomaterial was prepared by combining citric acid/collagen type I solutions with a brushite cement powder. The obtained biomaterial was a cement paste, with improved handling properties. The effect of collagen on the setting reaction of brushite cement was studied, and was found to speed up the cement setting reaction. The cement paste set into a hard ceramic material within 18.5+/-2.1min and had compressive strength similar to that of spongeous bone (48.9+/-5.9MPa in dry conditions and 12.7+/-1.5MPa in humid conditions). The combination of collagen with citric acid revealed an interesting synergistic effect on the compressive strength of the composite material. Moreover, this new biomaterial had excellent cohesion properties (ninefold better than brushite cement), and high cellular adhesion capacity (threefold higher than brushite cement). The composite biomaterial described in this study combines good handling properties, compressive strength, cohesion and cell adhesion capacity, along with the osteoconductive and biodegradable properties inherent in brushite and in collagen-based biomaterials.     

新型氯化锂复合磷酸钙骨水泥的理化性能及成骨特性

BACKGROUND: Lithium chloride is a widely used inorganic ion inhibitor of glycogen synthase kinase-3β, and it can be combined with glycogen synthase kinase-3β to activate the classical Wnt/β-catenin pathway, thereby promoting human bone marrow mesenchymal stem cells and osteoblasts proliferation and accelerating bone repair. OBJECTIVE: To observe the physicochemical properties of novel lithium chloride/calcium phosphate cement, and to explore its osteoinductive biological property. METHODS: Calcium phosphate cement served as control group, and lithium chloride/calcium phosphate cement containing different lithium content as experimental groups. The setting time and compressive strength of bone cement in each group were detected, and the microstructure of the material surface observed under scanning electron microscopy. Bone cement and MC3T3-E1 cells were co-cultured in vitro, and the growth and adhesion morphology of MC3T3-E1 cells on the surface of bone cement were observed under the scanning electron microscope. Effect of bone cement extracts on cell proliferation was determined through MTT assay, and alkaline phosphatase kit used for determining alkaline phosphatase activity. RESULTS AND CONCLUSION: Lithium chloride/calcium phosphate cement had the same physicochemical properties to the calcium phosphate cement. Initial and final setting time, compressive strength and morphology of bone cement had no significant differences among groups. MC3T3-E1 cells grew and adhered well on the material surface. Results of MTT assay showed that compared with the calcium phosphate cement, the lithium chloride/calcium phosphate cement was better to improve osteoblast proliferation in vitro. In addition, the alkaline phosphatase activity in MC3T3-E1 cells was higher in experimental groups than the control group. These findings indicate that lithium chloride/calcium phosphate cement can maintain good physicochemical properties, and release lithium ions to promote bone formation.       

陶瓷-树脂黏结剂黏结的研究进展

全瓷修复体以多种优良的特性赢得了医师和患者的青睐,其临床应用的成败很大程度上取决于陶瓷与树脂黏结剂的黏结强度。论述了黏结的重要性并围绕陶瓷的表面处理技术及材料的性质对黏结强度的影响等问题综述了陶瓷-树脂黏结剂黏结的最新进展。     

碳纤维增强α-磷酸三钙骨水泥的研究

为提高α-磷酸三钙（α—TCP）骨水泥的强度及降低其脆性，将表面改性后的碳纤维（CF）与α—TCP粉复合，制备成α—TCP／CF复合增强骨水泥。通过Ringer’s体液浸泡观察骨水泥快速结晶自固化能力，运用扫描电子显微镜（SEM）及抗压强度测试仪对复合材料浸泡后试样进行断面显微结构分析及抗压强度测试。结果显示，α—TCP骨水泥块浸泡5d后即转化生成片状羟基磷灰石晶体；适量的碳纤维在骨水泥基体中分布均匀，与基体结合性好，可得到抗压强度增强的骨修复材料；当碳纤维的加入重量百分数为0．5％时，复合材料抗压强度达到46．7MPa，比未增强的α—TCP材料提高了22％。