University Hospital Würzburg, Dept. Functional Materials in Medicine and Dentistry, Pleicherwall 2, D-97070 Würzburg, Germany.
Biomaterials. 2012 Sep;33(25):5887-900. doi: 10.1016/j.biomaterials.2012.04.053. Epub 2012 May 25.
Calcium phosphate cements (CPC) are well-established materials for the repair of bone defects with excellent biocompatibility and bioactivity. However, brittleness and low flexural/tensile strength so far restrict their application to non-load bearing areas. Reinforcement of CPC with fibers can substantially improve its strength and toughness and has been one major strategy to overcome the present mechanical limitations of CPC. Fiber reinforced calcium phosphate cements (FRCPC) thus bear the potential to facilitate the use of degradable bone substitutes in load bearing applications. This review recapitulates the state of the art of FRCPC research with focus on their mechanical properties and their biological evaluation in vitro and in vivo, including the clinical data that has been generated so far. After an overview on FRCPC constitutes and processing, some general aspects of fracture mechanics of reinforced cementitious composites are introduced, and their importance for the mechanical properties of FRCPC are highlighted. So far, fiber reinforcement leads to a toughness increase of up to two orders of magnitude. FRCPC have extensively been examined in vitro and in vivo with generally good results. While first clinical products focus on the improved performance of FRCPC with regard to secondary processing after injection such as fixation of screws and plates, first animal studies in load bearing applications show improved performance as compared to pure CPCs. Aside of the accomplished results, FRCPC bear a great potential for future development and optimization. Future research will have to focus on the selection and tailoring of FRCPC components, fiber-matrix compatibilization, integral composite design and the adjusted degradation behavior of the composite components to ensure successful long term behavior and make the composites strong enough for application in load bearing defects.
磷酸钙骨水泥（CPC）具有优异的生物相容性和生物活性，是修复骨缺损的成熟材料。然而，脆性和低弯曲/拉伸强度至今限制了其在非承重区域的应用。纤维增强 CPC 可以显著提高其强度和韧性，是克服 CPC 现有机械限制的主要策略之一。纤维增强磷酸钙骨水泥（FRCPC）因此具有在承重应用中促进可降解骨替代物使用的潜力。本综述回顾了 FRCPC 研究的最新进展，重点介绍了其机械性能及其在体外和体内的生物学评价，包括迄今为止获得的临床数据。在概述 FRCPC 的组成和加工之后，介绍了增强水泥基复合材料断裂力学的一些一般方面，并强调了它们对 FRCPC 机械性能的重要性。迄今为止，纤维增强可使韧性提高多达两个数量级。FRCPC 已经在体外和体内进行了广泛的研究，结果通常较好。虽然首批临床产品专注于 FRCPC 在注射后二次加工方面的性能改进，例如螺钉和板的固定，但首批承重应用的动物研究表明，与纯 CPC 相比，FRCPC 的性能有所提高。除了已取得的成果外，FRCPC 具有很大的发展和优化潜力。未来的研究必须集中在 FRCPC 组件的选择和定制、纤维-基体的相容性、整体复合材料设计以及复合材料组件的调整降解行为上，以确保长期成功的性能，并使复合材料足够坚固，可应用于承重缺陷。
