结构性多孔钽生物材料用于成人重建术的临床论证

在过去的三十年中，大多数钽珠烧结以及钽纤维丝弥散结合制造的多孔涂层，已用于骨科植入物的生物连接。近十年来，诞生了一种由商业纯钽制成的，具有独特物理和力学特性的新型多孔生物材料。与传统多孔涂层相比，该材料拥有更高的空隙容积、更自由连通的孔、与骨更高的摩擦系数，以及较低的成块硬化性（图1）。此外，该材料为结构性的，有足够的强度可以直接制造植入体，而无需实心的金属基质作支撑。     

钽金属在医学领域的应用

<正>钽是一种稀有高熔点金属,能经受高温和矿物酸的腐蚀,抗蚀能力与玻璃相同,在常温的空气中稳定。正因为钽金属所具有的高熔点、大强度、耐磨损、抗腐蚀等理化特性,因而其被大范围用于飞机、火箭等需要耐热材料以及需要高强度零部件的工业领域。不仅如此,钽金属还具有优良的生物相容性和稳定性,因此钽金属也被制造成各种接骨板以及螺钉用于医学领域。     

多孔钽金属治疗大鼠颅骨缺损的早期疗效

目的探讨多孔钽金属治疗大鼠颅骨缺损的早期治疗效果。方法采用钻孔法制备大鼠颅骨缺损动物模型, 采用随机数字表法将大鼠分为对照组, 钽金属植入组, 每组6只。通过小动物成像X光实验检测多孔钽金属注入情况;通过翻红O固绿染色及苏木精-伊红(HE)染色观察骨缺损处骨再生;通过多孔钽金属与骨髓间充质干细胞(BMSC)共培养探究其生物相容性, 通过扫描电镜观察BMSC共培养情况;通过噻唑蓝(MTT)法检测多孔钽金属生物毒性。结果多孔钽金属植入2周后与周围骨组织结合紧密, 未见明显炎性反应。小动物成像X光结果显示钽金属孔隙间可见新生骨长入, 促进骨缺损再生修复。组织学切片HE染色钽金属四周未见明显炎性反应, 金属孔隙间血细胞聚集, 促进骨痂形成;翻红O固绿染色可见新生骨长入金属间, 多孔钽金属与骨连接紧密, 未见免疫排斥反应。MTT检测实验结果显示正常培养组1、3、5 d后的吸光度值与钽金属共培养组比较, 差异无统计学意义(0.177±0.010比0.185±0.010、0.434±0.001比0.449±0.002、0.776±0比0.785±0, t=0.303、1.924、1.266, P&g...     

多孔钽在口腔临床中的应用与发展

半个世纪以来,钛金属作为主流骨植入材料广泛应用于临床,其力学强度优异,可满足生物安全性,但仍存在弹性模量与人体骨不匹配及易生理腐蚀的不足。国内外学者一直在寻找更为理想的生物材料,多孔钽应运而生。生物医用多孔钽突出的抗腐蚀性能,较高的延展性,极佳的生物相容性与功能性较钛金属显示出更强大的优势,引起了众多学者的关注与研究。本文就多孔钽的物理、化学、生物特性及现阶段在口腔临床中的应用与发展进行综述。     

AZ31B镁合金基体羟基磷灰石涂层材料的生物相容性研究

我们采用表面羟基磷灰石(hydroxyapatite,HAP)涂层制备HAP/AZ31B镁合金复合生物材料,检测镁合金生物材料的细胞毒性和生物适应性,为可降解镁金属植入材料在新型医用生物材料领域中的应用提供依据.     

多孔钽金属与成骨细胞生物相容性的实验研究

[目的]研究多孔钽金属体外与成骨细胞的生物相容性。[方法]按照ISO10993-12医疗器械生物学评价标准制备多孔钽金属材料浸提液,作用于人成骨细胞系hFOB1.19,标记为实验组,并设置空白对照组;MTT法检测材料浸提液对成骨细胞生长的影响;ELISA酶联免疫吸附法检测实验组及对照组碱性磷酸酶ALP及骨钙素OCN活性;将成骨细胞与多孔钽金属共培养,扫描电镜观察成骨细胞在材料上黏附和生长情况。[结果]实验组和对照组细胞增殖曲线、ALP和OCN活性相似,差异无统计学意义(P>0.05);成骨细胞与多孔钽金属材料共培养,显现出良好的黏附和生长行为。[结论]多孔钽金属对成骨细胞生长无不良影响,且适于成骨细胞黏附、生长及分化,具有良好的生物相容性。     

等离子喷涂钽涂层人工假体生物相容性研究

[目的]为钽(Ta)涂层人工假体临床应用的可行性提供实验依据.[方法]采用形态学脱察和四甲基偶氮唑盐(MTT)比色法,通过细胞毒性检测、细胞粘附性及增殖性研究对钽(Ta)涂层材料生物相容性进行评价.[结果]细胞形态学观察显示:Ta涂层组细胞形态良好,与对照组无差异;细胞毒性实验结果表明:Ta涂层细胞相对增殖率(RGR)为(113.2±0.01)%,与羟基磷灰石(HA)涂层(110.5±0.03)%及钛(Ti)涂层(109.8±0.05)%,无统计学差异(P>0.05),毒性分级均为0级,说明三种涂层材料对L929细胞的生长无抑制作用.细胞粘附性实验和增殖性实验结果显示:Ta涂层表面细胞粘附数量明显高于Ti涂层(P<0.05),与HA涂层无统计学差异(P>0.05),说明Ta涂层与Ti涂层表面相比,更适合细胞的粘附和生长.[结论]Ta涂层具有较好的细胞生物相容性,具有作为人工假体及其他生物材料表面改性的生物学基础.     

钽金属在骨科的临床应用

金属材料及其合金已在临床医学的各个领域得到广泛应用,并取得了显著的临床疗效.随着科技的不断发展,制备工艺的不断提高,越来越多的金属及合金材料应用到临床中.近年来,钽金属以其稳定的生物学特性、良好的生物相容性和特有的结构性质引起医学界,特别是骨科领域的广泛关注.本文就目前钽金属在骨科临床的应用现状作一综述.     

多孔金属钽假体在骨缺损修复中的应用

目的对多孔金属钽假体治疗骨缺损的研究现状作一综述。方法广泛查阅多孔金属钽假体特性及其治疗各种骨缺损的相关文献,并进行综述。结果多孔金属钽假体凭其特性,在某些类型的骨缺损治疗中效果显著。结论多孔金属钽假体存在着自身优缺点,在符合其适应证的前提下使用可取得较好近期疗效,为临床骨缺损修复提供了种新参考,但远期疗效需进一步观察。     

超细晶生物镁合金的制备及其耐腐蚀性能

与目前临床上普遍采用的不可降解金属骨植入材料相比,可降解生物镁合金具有比刚度、比强度高,密度、杨氏模量与人骨相近等特点,能有效降低应力遮挡效应,具有良好的可降解特性、生物相容性、生物活性及生物安全性,目前受到业界广泛关注[1],被认为是医学介入领域极具发展潜力的新型可降解医用金属材料,在治疗骨折和骨缺损方面具有潜在的优势。但作为骨植入材料,生物镁合金也逐渐显现出一系列问题（如力学性能不足、体内降解速率过快、腐蚀降解不均匀等）,无法满足植入后的骨支撑、骨诱导等服役性能要求。为此,研究者添加微量的合金元素,实现合金化以提高铸态镁合金的强度,但此类镁合金晶粒粗大、第二相偏析,存在较多组织缺陷,使得合金强度较低、塑性较差,无法满足其在医用材料领域的加工性能和使用性能,因此必须通过特种加工新技术来达到细化晶粒,改善第二相形态和分布,控制镁合金组织、力学性能和腐蚀均匀性的目的[2-3]。目前生物镁合金研究主要集中在生物镁合金及加工方法的开发、镁及镁合金的降解行为、镁合金器件的研发及表面改性等3个方面,其应用主要包括骨科修复植入体、心血管支架和组织工程支架。     

钽涂层对骨髓间充质干细胞的黏附增殖及成骨分化的影响

目的探讨钽涂层金属在体外促进大鼠骨髓间充质干细胞(BMSCs)黏附、增殖及成骨分化方面的作用。方法在体外取6只6周龄SD大鼠BMSCs进行原代培养至第3代,使用化学气相沉积系统自行制备钽涂层金属。然后进行流式细胞术鉴定、BMSCs三向诱导、荧光染色、细胞增殖检测及实时荧光定量聚合酶链反应技术(Q-PCR)试验。观察比较BMSCs在钛合金圆片(Ti6Al4V组)和钽金属圆片(Ta组)表面黏附的BMSCs数量、增殖速率、成骨细胞特异性转录因子(OSX)、Runt相关转录因子2(RUNX2)、骨粘连蛋白(OSN)和骨桥蛋白(OPN)的表达情况。结果流式细胞术结果显示CD44(94.55%)、CD90(95.01%)、CD34(0.06%)。诱导成骨分化14 d后碱性磷酸酶(ALP)染色阳性;诱导成骨分化21 d后出现茜素红钙化结节;成脂诱导21 d后油红O染色呈阳性;成软骨诱导21 d后阿利新蓝染色评估有软骨形成能力。激光共聚焦显微镜结果显示BMSCs在Ti6Al4V组和Ta组金属圆片表面贴附生长,细胞间互相接触、聚集成片,Ta组金属圆片上黏附的BMSCs数量明显多于Ti6Al4V组,并且具有更好的延展性能。细胞增殖检测结果发现,分别共培养1、3、5、7 d后Ta组BMSCs的增殖速率明显快于Ti6Al4V组,差异均有统计学意义(P<0.05)。Q-PCR结果发现,与Ti6Al4V组相比,体外培养7 d后Ta组金属圆片更能促进OSN和OPN的表达,差异有统计学意义(P<0.05);体外共培养21 d后,Ta组金属圆片更能促进OSX、RUNX2、OSN和OPN的表达,差异均有统计学意义(P<0.05)。结论相比于传统的骨科植入物钛合金而言,钽涂层金属能够更好地促进BMSCs的黏附,增殖和成骨分化。     

Experimental study of metallic bone and joint prostheses with plasma-sprayed ceramic coating]

In order to solve the loosening problem of endoprosthesis, a titanium-based alloy bone and joint prosthesis with plasma-sprayed ceramic coating was developed by the authors. By the fabrication powdered alumina or zirconium oxide were melted in an electric arc by a temperature of 10,000 K and sprayed onto the metallic prosthesis. The coating was 0.3 to 0.6 mm in thickness and had innumerable micropores. The pores were 50 to 200 microns in diameter. The metallic bone and joint prosthesis with plasma-sprayed ceramic coating exhibits characteristics of metal and ceramic, such as high mechanical strength, high resistance to corrosion and elution and good biocompatibility. According to our experimental study, the plasma-sprayed ceramic coating allows tissue ingrowth into its micropores and prevents the loosening of the prosthesis. Successful cases have been experienced through 10 years clinical application.     

Fatigue failure of noncemented porous-coated implants. A retrieval study

The causes of mechanical failure of five noncemented porous-coated components were studied. There were two cobalt-chromium alloy and three titanium alloy implants which fractured after 12 to 48 months. The implants included one acetabular component, and one femoral condylar, one patellar and two tibial components. Examination of the fractured surfaces revealed fatigue to be the mechanism of failure in all cases. The porous coating and the processes required for its fabrication had resulted in weakening and reduction of substrate thickness. Additional factors were stress concentration due to limited, localised bone ingrowth, and some features of the design of the implants.     

壳聚糖表面改性钛合金材料的研究进展

钛合金材料生物性能良好,是骨科常用的内植入材料,但其骨整合性及抗菌性能较差,需进行表面改性以弥补其不足之处。壳聚糖具有良好的生物相容性及成膜性,且可作为载体将目标药物引入钛合金表面,可有效改善钛合金材料的生物学性能,增加其使用范围。本文对近几年壳聚糖表面改性钛合金材料的相关研究进行归纳总结,从壳聚糖涂层改性的方式、钛合金材料成骨性及抗菌性的改善3个方面展开论述,以期为钛合金材料涂层改性在临床中的应用提供指导依据。     

Corrosion Behavior of Tantalum-Coated Cobalt–Chromium Modular Necks Compared to Titanium Modular Necks in a Simulator Test

This study compared the corrosion behavior of tantalum-coated cobalt–chromium modular necks with that of titanium alloy modular necks at their junction to titanium-alloy femoral stem. Tests were performed in a dry assembly and two wet assemblies, one contaminated with calf serum and the other contaminated with calf serum and bone particles. Whereas the titanium modular neck tested in the dry assembly showed no signs of corrosion, the titanium modular necks tested in both wet assemblies showed marked depositions and corrosive attacks. By contrast, the tantalum-coated cobalt–chromium modular necks showed no traces of corrosion or chemical attack in any of the three assemblies. This study confirms the protective effect of tantalum coating the taper region of cobalt–chromium modular neck components, suggesting that the use of tantalum may reduce the risk of implant failure due to corrosion.     

Porous tantalum in reconstructive surgery of the knee: a review

Porous tantalum represents an alternative metal for primary and revision total knee arthroplasty (TKA) with several unique properties. Tantalum is a transition metal, which in its bulk form has shown excellent biocompatibility and is safe to use in vivo as evidenced by its current application in pacemaker electrodes, cranioplasty plates, and as radiopaque markers. Current designs for orthopedic implants maintain a high volumetric porosity (70%-80%), low modulus of elasticity (3 MPa), and high frictional characteristics, making this metal conducive to biologic fixation. The low modulus of elasticity of such components allows for more physiologic load transfer and relative preservation of bone stock. Its more bioactive nature and ingrowth properties have led to its use in primary as well as revision knee components with good early clinical results reported. In revision arthroplasty, it has been used as a structural bone graft substitute. Formation of a bone-like apatite coating in vivo affords strong fibrous ingrowth properties and allows for substantial soft-tissue attachment with the potential for use in cases such as mega-prostheses and patella salvage. Although porous tantalum is in its early stages of evolution, the initial clinical data and basic science studies support its use as an alternative to traditional orthopedic implant materials.     

Bacterial adherence to tantalum versus commonly used orthopedic metallic implant materials

OBJECTIVES: Evaluation of bacterial adhesion to pure tantalum and tantalum-coated stainless steel versus commercially pure titanium, titanium alloy (Ti-6Al-4V), and grit-blasted and polished stainless steel. DESIGN: Experimental in vitro cell culture study using Staphylococcus aureus and Staphylococcus epidermidis to evaluate qualitatively and quantitatively bacterial adherence to metallic implants. METHODS: A bacterial adhesion assay was performed by culturing S. aureus (ATCC 6538) and S. epidermidis (clinical isolate) for one hour with tantalum, tantalum-coated stainless steel, titanium, titanium alloy, grit-blasted and polished stainless steel metallic implant discs. Adhered living and dead bacteria were stained using a 2-color fluorescence assay. Adherence was then quantitatively evaluated by fluorescence microscopy and digital image processing. Qualitative adherence of the bacteria was analyzed with a scanning electron microscope. The quantitative data were related to the implant surface roughness (Pa-value) as measured by confocal laser scanning microscopy. RESULTS: Bacterial adherence of S. aureus varied significantly (p = 0.0035) with the type of metallic implant. Pure tantalum presented with significantly (p < 0.05) lower S. aureus adhesion compared to titanium alloy, polished stainless steel, and tantalum-coated stainless steel. Furthermore, pure tantalum had a lower, though not significantly, adhesion than commercially pure titanium and grit-blasted stainless steel. Additionally, there was a significantly higher S. aureus adherence to titanium alloy than to commercially pure titanium (p = 0.014). S. epidermidis adherence was not significantly different among the tested materials. There was no statistically significant correlation between bacterial adherence and surface roughness of the tested implants. CONCLUSIONS: Pure tantalum presents with a lower or similar S. aureus and S. epidermidis adhesion when compared with commonly used materials in orthopedic implants. CLINICAL IMPLICATION: Because bacterial adhesion is an important predisposing factor in the development of clinical implant infection, tantalum may offer benefits as an adjunct or alternative material compared with current materials commonly used for orthopedic implants.     

Applications of porous tantalum in total hip arthroplasty

Porous tantalum is an alternative metal for total joint arthroplasty components that offers several unique properties. Its high volumetric porosity (70% to 80%), low modulus of elasticity (3 MPa), and high frictional characteristics make it conducive to biologic fixation. Tantalum has excellent biocompatibility and is safe to use in vivo. The low modulus of elasticity allows for more physiologic load transfer and relative preservation of bone stock. Because of its bioactive nature and ingrowth properties, tantalum is used in primary as well as revision total hip arthroplasty components, with good to excellent early clinical results. In revision arthroplasty, standard and custom augments may serve as a structural bone graft substitute. Formation of a bone-like apatite coating in vivo affords strong fibrous ingrowth properties and allows for substantial soft-tissue attachment, indicating potential for use in cases requiring reattachment of muscles and tendons to a prosthesis. Development of modular components and femoral stems also is being evaluated. The initial clinical data and basic science studies support further investigation of porous tantalum as an alternative to traditional implant materials.     

Highly Porous Tantalum Acetabular Components Without Ancillary Screws Have Similar Migration to Porous Titanium Acetabular Components With Screws at 2 Years: A Randomized Controlled Trial

BackgroundIt is proposed that highly porous coatings on acetabular components, such as a porous tantalum coating, provide adequate fixation without ancillary screw fixation in primary total hip arthroplasty (THA). However, tantalum acetabular components have been associated with higher rates of revision than other uncemented components in national registries. The aim of this randomized controlled trial is to determine whether the early migration of a solid-backed tantalum acetabular component was no greater than that of a titanium acetabular component with ancillary screw fixation that has proven good clinical results.MethodsSixty-six patients aged 40 to 64 years, with osteoarthritis and Charnley grade A or B activity grade and who underwent primary THA, were recruited into the trial. Patients were randomized intraoperatively to receive either the tantalum or titanium acetabular component. All patients received the same cemented polished tapered femoral stem, 28-mm cobalt-chromium femoral head, and highly cross-linked polyethylene liner. Acetabular component migration was measured using radiostereometric analysis at 4-6 days postoperatively and at 6 weeks, 3 months, 1 and 2 years following THA.ResultsThe mean proximal migration at 2 years for the tantalum cohort was 0.17 mm (95% confidence interval, 0.09-0.24) which was no greater than that of the titanium cohort which was 0.19 mm (0.07-0.32). Harris hip scores and functional activity scores were similar between groups.ConclusionThese results demonstrate that early stability can be achieved without ancillary screw fixation through the use of a highly porous high friction coating on a solid-backed modular acetabular component.Level of EvidenceLevel I.