Rotsch Christian, Kemter-Esser Karoline, Dohndorf Johanna, Funke Kerstin, Heyde Christoph-Eckhard, Drossel Welf-Guntram
Fraunhofer Institute for Machine Tools and Forming Technology IWU, 01187 Dresden, Germany.
Department of Orthopaedic, Trauma and Plastic Surgery, University of Leipzig Medical Center, 04103 Leipzig, Germany.
Bioengineering (Basel). 2024 Aug 27;11(9):868. doi: 10.3390/bioengineering11090868.
The revision of ceramic inlays of acetabular cups is a challenging surgical procedure. The mechanical impact during the inlay extraction process can damage the ceramic or metal cup rim. To avoid these risks, a concept for a new revision procedure was developed. It is based on an actuator system, which allows a non-destructive release of the ceramic inlay. To integrate the actuator system, different design concepts of acetabular cup components were investigated, and an actuator based on shape-memory alloy (SMA) wires was developed. The process chain for the actuator, starting from nickel-titanium wires manufactured into the actuator geometry by laser welding and thermo-mechanical treatment for the shape setting process up to the functionality evaluation of the actuator system, was implemented on a laboratory scale. The new revision procedure is based on a phase transformation of the SMA wire actuator, which was obtained through two methods-applying an electrical current by an instrument and rinsing the wire with heated water. The phase transformation of the actuator resulted in a contraction between 3.2% and 4.3% compared to its length after pre-stretching and was able to release the ceramic inlay from the cup. Therefore, the developed actuator design and process chain is a proof of concept towards a new revision procedure for modular acetabular cups.
髋臼杯陶瓷内衬的翻修是一项具有挑战性的外科手术。内衬取出过程中的机械冲击可能会损坏陶瓷或金属杯缘。为避免这些风险,开发了一种新的翻修手术概念。它基于一个执行器系统,该系统可实现陶瓷内衬的无损释放。为集成该执行器系统,研究了髋臼杯组件的不同设计概念,并开发了一种基于形状记忆合金(SMA)丝的执行器。在实验室规模上实现了执行器的工艺链,从通过激光焊接和热机械处理将镍钛丝制成执行器几何形状以进行形状设定过程,到执行器系统的功能评估。新的翻修手术基于SMA丝执行器的相变,该相变通过两种方法实现——用仪器施加电流和用热水冲洗丝。与预拉伸后的长度相比,执行器的相变导致收缩率在3.2%至4.3%之间,并且能够从杯中释放陶瓷内衬。因此,所开发的执行器设计和工艺链是模块化髋臼杯新翻修手术概念验证。