小梁金属(多孔钽)在骨科的应用现状

骨科学科的发展与手术器械和植入材料的发展密不可分.小梁金属(多孔钽)是近年来出现的一种较理想的骨科植入材料,由纯商业钽制成,它克服了目前临床上常用的不锈钢及钛、镍、钴、铬等金属的合金制成的植入器械整体孔隙率低、表面摩擦系数小、弹性模量较高等缺点,具有较大的空隙率与表面摩擦力、有与人体骨质接近的弹性模量、有更低的成块硬化性、有较好的生物相容性,被认为是一种较理想的骨科植入材料[1].小梁金属虽然国内还未见使用,但在国外已广泛应用于骨科临床.本文就多孔钽的理化、生物学特性及在骨科中的应用现状作一介绍.     

多孔钽骨科临床应用概况

多孔钽植入物极好的生物相容性及与松质骨类似的微观结构,业已引起生物医学界的广泛关注.骨科临床应用多孔钽于股骨头坏死、全髋关节置换、全膝关节置换、椎间融合的短期疗效令人鼓舞.该文就多孔钽在骨科的临床应用作一简要综述.     

多孔钽骨科临床应用概况

多孔钽植入物极好的生物相容性及与松质骨类似的微观结构,业已引起生物医学界的广泛关注。骨科临床应用多孔钽于股骨头坏死、全髋关节置换、全膝关节置换、椎间融合的短期疗效令人鼓舞。该文就多孔钽在骨科的临床应用作一简要综述。     

多孔钽骨科临床应用概况

多孔钽植入物极好的生物相容性及与松质骨类似的微观结构，业已引起生物医学界的广泛关注。骨科临床应用多孔钽于股骨头坏死、全髋关节置换、全膝关节置换、椎间融合的短期疗效令人鼓舞。该文就多孔钽在骨科的临床应用作一简要综述。     

多孔钽材料制备及其骨科植入物临床应用现状

多孔钽具有高孔隙率、低弹性模量、高摩擦系数、组织内生性及软骨传导性等特性,是理想的骨科材料。近年来,对多孔钽制备技术的研究以及多孔钽植入器械的临床应用取得令人鼓舞的结果。该文就多孔钽的材料制备及生物学特性,多孔钽植入器械在人工关节外科、脊柱外科等方面的临床应用进展作一综述。     

多孔钽金属在临床骨关节修复中的应用

随着生物材料的发展,多孔钽金属因优良性能而被应用于临床骨关节修复中。在人工关节置换术中,多孔钽假体较其他假体磨损少,且固定稳定;在关节翻修术中,采用多孔钽假体进行髋、膝关节翻修术,成功率高;在早期股骨头缺血性坏死修复中,多孔钽假体可有效预防股骨头塌陷;在骨肿瘤切除术及脊柱融合术中,多孔钽假体具有良好的促骨再生性;在踝关节和距下关节置换术中,多孔钽假体早期效果良好。该文就多孔钽金属在临床关节修复中的应用作一综述。     

骨科金属内置物材料的生物学特性及应用进展

[目的]综述国内外骨科金属内置物材料的生物学特性及相关应用进展,明确其在临床骨科中的最佳应用效果。[方法]广泛查阅近年来常用的骨科金属内置物材料相关文献,尤其是新型合金材料的资料,总结归纳其研究现状及未来发展方向。[结果]目前骨科金属内置物材料已从单一金属发展到合金阶段,分别利用其力学特点及生物学特性,从追求单纯牢固及理化性质稳定发展到降低弹性模量甚至控制其降解。[结论]多种金属材料组合可取长补短,骨科金属内置物材料的研究仍将不断突破。     

医用金属表面的钽涂层制备及其临床应用趋势

金属钽具有极佳的耐腐蚀性和优异的生物相容性,目前受到越来越多的医学和材料科学工作者的关注,但其高昂的原料成本限制了其在生物医用领域的广泛应用,因此人们采用多种方法制各钽涂层以降低成本。该文综述钽的生物学优势,医用金属（不锈钢、钛合金、钴铬合金）表面的钽涂层制备及其临床应用趋势。     

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。     

胶原膜/国产多孔钽金属双相支架修复山羊大面积骨软骨缺损的实验研究

背景:骨软骨联合病变是骨科常见疾病,一直缺乏有效的治疗手段。目的:通过使用胶原膜联合自主研发的三维多孔钽金属支架,设计构建了一种新型的仿生骨组织工程复合体,并探讨其修复山羊大面积骨软骨缺损的效果。方法:将多孔碳化硅支架通过化学气相沉积技术制备成多孔钽金属,然后采用纤维蛋白黏合剂将胶原膜及自主研发的多孔钽金属进行界面结合,得到双相支架材料;在体外通过扫描电镜观察胶原膜及多孔钽的微观形貌,并通过能谱分析测定其组成成分;万能力学测试机进行双相支架材料的力学检测。32只雄性山羊采用随机数字表法分为4组,每组各8只,于左后肢建立骨软骨缺损模型(缺损面积直径为10 mm,深度为12 mm)。单纯骨软骨缺损组不做任何治疗,其余3组分别采用单纯胶原膜、单纯国产多孔钽金属、胶原膜/国产多孔钽金属双相支架修复。植入16周后进行大体观察及硬组织切片、染色,并进行定量分析。结果:扫描电镜观察结果表明,双相支架结合面均匀、光滑、牢固。能谱分析表明,胶原膜由碳、氧、钙3种元素组成,国内多孔钽金属主要由碳、硅和钽组成。该支架具有良好的抗压强度、抗拉强度、粘结强度和抗剪强度。植入山羊负重区大面积骨软骨缺损区16周后,国际软骨修复学会评分(ICRS)及改良O'Driscoll组织学评分结果显示,与单纯多孔钽金属组、单纯胶原膜组及单纯骨软骨缺损组相比,胶原膜/国产多孔钽金属双相支架组具有明显的骨软骨修复效果(P<0.05)。结论:本研究对于在负重区的大面积骨软骨缺损的成功修复显示了临床转化的潜能。为大面积骨软骨联合病变的临床治疗提供新的组织工程思路。     

Biocompatible Porous Tantalum Metal Plates in the Treatment of Tibial Fracture

Fractures of the tibia represent a common class of injuries in orthopedics. The blood supply to the tibia is poor due to the small subcutaneous muscle tissues inside. Consequently, the tibia is prone to delayed fracture healing and nonunion of the fracture after surgery. In this case, we used porous tantalum metal plate to treat nonunion of a tibial fracture and achieved satisfactory therapeutic effects. For the first time in the field, we used 3D printing technology to fabricate porous tantalum metal plates for the treatment of tibial fractures. The resulting porous tantalum metal exhibited excellent mechanical and biological properties, and improved the therapeutic effects for the treatment of a tibial fracture nonunion. Porous tantalum metal plates have great application potential as a new implant material for internal fixation.     

Midterm results of a porous tantalum monoblock tibia component clinical and radiographic results of 108 knees

The use of Trabecular Metal (TM), a biomaterial manufactured from elemental tantalum metal, has recently increased in orthopedics. One hundred eight consecutive TM monoblock tibias were implanted in 95 patients and followed for a minimum of 2 years. The average follow-up was 4.5 years. The average age was 65 years. The Knee Society score of 36 improved to 89. One hundred five of the knees were rated good/excellent, and 3 knees were rated poor. Two patellar revisions were performed for loose components and one for patellar misalignment. One patella fracture required open reduction and internal fixation. One femur was revised. There were no tibia revisions. There were no progressive radiographic lucencies. Midterm clinical and radiographic results of 108 consecutive TM tibia components have a high rate of success.     

Vitallium

Vitallium is a base metal alloy that has been used in dentistry and medicine since 1929. This article will focus on the historical perspectives of Vitallium and include the dental and medical applications used today. The physical and chemical properties of Vitallium will be discussed, with particular emphasis on the biocompatibility of the metal. Finally, the future uses of Vitallium will be examined, as will the potential dangers in fabricating prostheses using this base metal alloy.     

Composite resin in medicine and dentistry

Composite resin has been used for nearly 50 years as a restorative material in dentistry. Use of this material has recently increased as a result of consumer demands for esthetic restorations, coupled with the public's concern with mercury-containing dental amalgam. Composite is now used in over 95% of all anterior teeth direct restorations and in 50% of all posterior teeth direct restorations. Carbon fiber reinforced composites have been developed for use as dental implants. In medicine, fiber-reinforced composites have been used in orthopedics as implants, osseous screws, and bearing surfaces. In addition, hydroxyapatite composite resin has become a promising alternative to acrylic cement in stabilizing fractures and cancellous screw fixation in elderly and osteoporotic patients. The use of composite resin in dentistry and medicine will be the focus of this review, with particular attention paid to its physical properties, chemical composition, clinical applications, and biocompatibility.     

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.     

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。     

Off-the-shelf 3D printed titanium cups in primary total hip arthroplasty

Three-dimensional (3D)-printed titanium cups used in primary total hip arthroplasty (THA) were developed to combine the benefits of a low elastic modulus with a highly porous surface. The aim was to improve local vascularization and bony ingrowth, and at the same time to reduce periprosthetic stress shielding. Additive manufacturing, starting with a titanium alloy powder, allows serial production of devices with large interconnected pores (trabecular titanium), overcoming the drawbacks of tantalum and conventional manufacturing techniques. To date, 3D-printed cups have achieved dependable clinical and radiological outcomes with results not inferior to conventional sockets and with good rates of osseointegration. No mechanical failures and no abnormal ion release and biocompatibility warnings have been reported. In this review, we focused on the manufacturing technique, cup features, clinical outcomes, open questions and future developments of off-the-shelf 3D-printed titanium shells in THA.     

Middle term results of tantalum acetabular cups in total hip arthroplasty following pelvic irradiation

ObjectivesThe aim of this study was to evaluate the middle term cup survival, assess the functional implementation and the radiographic evolution of tantalum acetabular cups implanted on patients with a history of pelvic radiotherapy.MethodsFrom 2005 to 2013, we performed 12 THA replacements (4 males 8 females; mean age: 46.6 years (range 25–75)) on irradiated bone with Trabecular metal acetabular cups, 8 primary implants and 4 revision implants. The mean radiation dose delivered was 5500 cGy (range 3000 cGy–13,600 cGy). The mean follow-up was 68 months, ranging from 38 to 136. Postoperative follow-up time was assessed at 1, 3, 6 and 12 months, then annually. Double projection radiographs were requested at each control. Radiographic signs of loosening were investigated by X-rays looking for radiolucent lines. We used the Harris hip score for the clinical and functional evaluation.ResultsTo now none of the 12 patients in the series needed any revision surgery for aseptic loosening. In the revision group one patient have been revised for septic loosening, two patients have been treated by conservative procedure for hip dislocation. Post-operative Harris hip score improved from an average of 46 points to 85.3 points. At last follow-up we found only in one case radiographic signs of progressive lucent line, without clinical sign of failure.ConclusionIn a clinical setting, tantalum cup seems to provide a good stability due to the integration of the trabecular metal to the underline cancellous bone. The reported results, in agreement with literature data, propose the use of tantalum cups in irradiated bone.Level of evidenceLevel IV, therapeutic study.