Faculty of Engineering, University of Applied Science, Technology, Business and Design, Philipp-Müller-Str. 14, 23966 Wismar, Germany; Biomechanics and Implant Technology Research Laboratory, Department of Orthopedics, Rostock University Medicine, Doberaner Strasse 142, Rostock 18057, Germany.
Institute for Polymer Technologies e.V., Alter Holzhafen 19, 23966 Wismar, Germany.
J Mech Behav Biomed Mater. 2018 Apr;80:1-10. doi: 10.1016/j.jmbbm.2018.01.015.
Today hip cups are used in a large variety of design variants and in increasing numbers of units. Their development is steadily progressing. In addition to conventional manufacturing methods for hip cups, additive methods, in particular, play an increasingly important role as development progresses. The present paper describes a modified cup model developed based on a commercially available press-fit cup (Allofit 54/JJ). The press-fit cup was designed in two variants and manufactured using selective laser melting (SLM). Variant 1 (Ti) was modeled on the Allofit cup using an adapted process technology. Variant 2 (Ti-S) was provided with a porous load bearing structure on its surface. In addition to the typical (complete) geometry, both variants were also manufactured and tested in a reduced shape where only the press-fit area was formed. To assess the primary stability of the press-fit cups in the artificial bone cavity, pull-out and lever-out tests were carried out. Exact fit conditions and two-millimeter press-fit were investigated. The closed-cell PU foam used as an artificial bone cavity was mechanically characterized to exclude any influence on the results of the investigation. The pull-out forces of the Ti-variant (complete-526 N, reduced-468 N) and the Ti-S variant (complete-548 N, reduced-526 N) as well as the lever-out moments of the Ti-variant (complete-10 Nm, reduced-9.8 Nm) and the Ti-S variant (complete-9 Nm, reduced-7.9 N) show no significant differences in the results between complete and reduced cups. The results show that the use of reduced cups in a press-fit design is possible within the scope of development work.
如今，髋杯有多种设计变体，且应用数量不断增加。其发展稳步推进。除了传统的髋杯制造方法外，随着技术的发展，增材方法尤其越来越重要。本文介绍了一种基于市售压配合髋杯（Allofit 54/JJ）开发的改良杯模型。该压配合杯设计有两种变体，并使用选择性激光熔化（SLM）制造。变体 1（Ti）采用经改良的工艺技术，基于 Allofit 杯建模。变体 2（Ti-S）在其表面设置了多孔承重结构。除了典型（完整）几何形状外，两种变体还以仅形成压配合区域的简化形状制造和测试。为评估压配合髋杯在人工骨腔中的初始稳定性，进行了拔出和杠杆拔出测试。研究了完全配合条件和 2 毫米压配合。作为人工骨腔使用的闭孔型聚氨酯泡沫进行了力学特性表征，以排除其对研究结果的任何影响。Ti 变体（完整-526 N，简化-468 N）和 Ti-S 变体（完整-548 N，简化-526 N）的拔出力以及 Ti 变体（完整-10 Nm，简化-9.8 Nm）和 Ti-S 变体（完整-9 Nm，简化-7.9 Nm）的杠杆拔出力矩的结果表明，在开发工作范围内，压配合设计中使用简化杯是可行的。
