Evans Nathan T, Torstrick F Brennan, Safranski David L, Guldberg Robert E, Gall Ken
School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, J. Erskine Love Building, Atlanta, GA 30332, United States.
School of Mechanical Engineering, Georgia Institute of Technology, 801 Ferst Drive, Atlanta, GA 30332, United States.
J Mech Behav Biomed Mater. 2017 Jan;65:522-532. doi: 10.1016/j.jmbbm.2016.09.006. Epub 2016 Sep 14.
Surface porous polyether-ether-ketone has the ability to maintain the tensile monotonic and cyclic strength necessary for many load bearing orthopedic applications while providing a surface that facilitates bone ingrowth; however, the relevant deformation behavior of the pore architecture in response to various loading conditions is not yet fully characterized or understood. The focus of this study was to examine the compressive and wear behavior of the surface porous architecture using micro Computed Tomography (micro CT). Pore architectures of various depths (~0.5-2.5mm) and pore sizes (212-508µm) were manufactured using a melt extrusion and porogen leaching process. Compression testing revealed that the pore architecture deforms in the typical three staged linear elastic, plastic, and densification stages characteristic of porous materials. The experimental moduli and yield strengths decreased as the porosity increased but there was no difference in properties between pore sizes. The porous architecture maintained a high degree of porosity available for bone-ingrowth at all strains. Surface porous samples showed no increase in wear rate compared to injection molded samples, with slight pore densification accompanying wear.
表面多孔聚醚醚酮能够保持许多承重骨科应用所需的拉伸单调和循环强度，同时提供有利于骨长入的表面；然而，孔隙结构在各种加载条件下的相关变形行为尚未得到充分表征或理解。本研究的重点是使用微型计算机断层扫描（micro CT）检查表面多孔结构的压缩和磨损行为。采用熔体挤出和致孔剂浸出工艺制造了各种深度（约0.5 - 2.5mm）和孔径（212 - 508µm）的孔隙结构。压缩测试表明，孔隙结构在多孔材料典型的三个阶段（线性弹性、塑性和致密化阶段）发生变形。随着孔隙率增加，实验模量和屈服强度降低，但不同孔径之间的性能没有差异。在所有应变下，多孔结构都保持了高度的孔隙率以供骨长入。与注塑样品相比，表面多孔样品的磨损率没有增加，磨损伴随着轻微的孔隙致密化。
