Hamburg University of Applied Sciences, Faculty of Life Sciences, Hamburg, Germany.
Depuy-Synthes, Leeds, United Kingdom.
PLoS One. 2022 May 20;17(5):e0268561. doi: 10.1371/journal.pone.0268561. eCollection 2022.
Press-fitted implants are implanted by impaction to ensure adequate seating, but without overloading the components, the surgeon, or the patient. To understand this interrelationship a uniaxial discretised model of the hammer/introducer/implant/bone/soft-tissues was developed. A parametric analysis of applied energy, component materials and geometry, and interactions between implant and bone and between bone and soft-tissues was performed, with implant seating and component stresses as outcome variables. To reduce the impaction effort (energy) required by the surgeon for implant seating and also reduce stresses in the hardware the following outcomes were observed: Reduce energy per hit with more hits / Increase hammer mass / Decrease introducer mass / Increase implant-bone resistance (eg stem roughness). Hardware stiffness and patient mechanics were found to be less important and soft tissue forces, due to inertial protection by the bone mass, were so low that their damage would be unlikely. This simple model provides a basic understanding of how stress waves travel through the impacted system, and an understanding of their relevance to implantation technique and component design.
压配式植入物通过撞击植入以确保充分的就位，但不会使部件、外科医生或患者过载。为了理解这种相互关系，开发了一种锤子/引入器/植入物/骨骼/软组织的单轴离散模型。对施加的能量、部件材料和几何形状以及植入物与骨骼之间以及骨骼与软组织之间的相互作用进行了参数分析，以植入物的就位和部件的应力作为结果变量。为了减少外科医生植入物就位所需的撞击力（能量）并降低硬件中的应力，观察到以下结果：通过增加撞击次数/增加锤子质量/减少引入器质量/增加植入物-骨骼阻力（例如，增加杆部粗糙度）来减少每次撞击的能量。发现硬件刚度和患者力学不太重要，并且由于骨骼质量的惯性保护，软组织力非常低，因此不太可能造成损伤。这个简单的模型提供了对冲击系统中应力波如何传播的基本理解，以及对其与植入技术和部件设计的相关性的理解。
