López G D
Instituto de Desarrollo y Diseño (INGAR), Santa Fe, Argentina.
Medicina (B Aires). 1993;53(3):260-74.
The use of surgical implants and prosthetic devices to replace the original function of different components of the human biological system is a well established tradition in the history of medicine. Currently, one of the most prevalent points of view in dealing with this subject, is that of biocompatibility of materials of construction and methods of fabrication of these devices, in order to avoid negative impacts on the patient due to failure of implants through degradation mechanisms such as corrosion. This article presents a current general review of the relationship between biocompatibility and deterioration of metallic implants and prosthetic devices, emphasizing the specific forms that corrosion adopts in biological media. The historical perspective shows the consolidation of a tendency towards a more systematic study of these phenomena in recent years, as opposed to trial and error practices that used to be common before the third decade of this century. The understanding of interactions between implants and biological tissue, thus led to some of the most promising current techniques, such as the use of powder metallurgy components to optimize skeletal fixation of implants by means of interstitial bone growth into porous metallic surfaces. The review of metals and alloys currently used for the fabrication of implants shows the amplitude of available technological alternatives, as well as the multiple criteria required to make a good selection for each specific case. Applications and pros and cons of stainless steel, Cr, Ni, Co and Ti alloys, and tantalum are briefly discussed. The introduction to basic concepts of corrosion, serves as a basis for the description of the typical forms that these phenomena adopt in biological media, including pitting, crevice corrosion, fatigue-corrosion, stress corrosion, fretting corrosion, galvanic corrosion, and intergranular corrosion. This review shows that the study of interactions between biological media and metallic implants has become a well established and specific field of science. As a result of this conclusion, an interdisciplinary treatment of the subject of biodeterioration of metallic implants and prosthetic devices is proposed. In practical terms, this proposal can be understood as the integration of an expert in materials science and engineering to the medical team. Thus, quality and reliability of the implant, as well as maximization of its useful life, would be achieved through the implementation of technical specifications, accepted standards, and pertinent testing as recommended by the above mentioned expert, who will be the person of the team more able to grasp the novelties that the dynamic field of biomaterials constantly offers.
使用外科植入物和假体装置来替代人体生物系统不同部件的原始功能，在医学史上是一个由来已久的传统。目前，在处理这个问题时，最普遍的观点之一是构建材料和这些装置制造方法的生物相容性，以避免由于植入物通过腐蚀等降解机制失效而对患者产生负面影响。本文对金属植入物和假体装置的生物相容性与劣化之间的关系进行了当前的综合综述，强调了腐蚀在生物介质中呈现的具体形式。历史视角表明，近年来对这些现象进行更系统研究的趋势得到了巩固，这与本世纪第三个十年之前常见的试错做法形成了对比。对植入物与生物组织之间相互作用的理解，催生了一些当前最有前景的技术，比如使用粉末冶金部件，通过骨间隙生长到多孔金属表面来优化植入物的骨骼固定。对目前用于制造植入物的金属和合金的综述展示了可用技术选择的范围，以及针对每个具体案例进行良好选择所需的多个标准。简要讨论了不锈钢、铬、镍、钴和钛合金以及钽的应用和优缺点。腐蚀基本概念的介绍，为描述这些现象在生物介质中呈现的典型形式奠定了基础，包括点蚀、缝隙腐蚀、疲劳腐蚀、应力腐蚀、微动腐蚀、电偶腐蚀和晶间腐蚀。这篇综述表明，生物介质与金属植入物之间相互作用的研究已成为一个成熟且特定的科学领域。基于这一结论，提出了对金属植入物和假体装置生物劣化问题进行跨学科处理的建议。实际上，这一建议可理解为将材料科学与工程领域的专家纳入医疗团队。这样，通过执行上述专家推荐的技术规范、公认标准和相关测试，将实现植入物的质量和可靠性以及其使用寿命的最大化，这位专家将是团队中最能够把握生物材料动态领域不断提供的新事物的人。
