Finite element analysis of primary stability in cementless tibial components with varying interference fits

IF 1.4 3区医学 Q4 ENGINEERING, BIOMEDICAL

Clinical Biomechanics Pub Date : 2025-05-01 DOI:10.1016/j.clinbiomech.2025.106539

Esther Sánchez , Miriam R. Boot , Christoph Schilling , Thomas M. Grupp , Alexander Giurea , Nico Verdonschot , Dennis Janssen

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引用次数: 0

Abstract

Background

Cementless knee implants achieve initial fixation through an interference fit, where the tibial implant is press-fitted into an undersized bone cavity. The dimensions between the implant and bone cuts must be carefully balanced to achieve an optimal interference fit, ensuring good primary stability, which is crucial for long-term fixation and successful osseointegration. However, the ideal interference fit remains uncertain. Excessive interference fit may lead to bone plastic deformation, while insufficient fit can result in large micromotions, small movements at the bone-implant interface, that compromise stability. This study evaluates how interference fit affects bone plasticity and micromotions, and how different loading conditions influence primary stability using finite element analysis.

Methods

Finite element models, based on experimentally implanted components, simulated interference fits of 350 μm and 700 μm. Micromotions, gap dynamics, and bone deformation were assessed during gait and squat activities under both simplified and complex loading conditions.

Findings

Higher interference fits increased bone plastic deformation, limiting elastic energy accumulation, whereas lower interference fits exhibited a reduced effect. Micromotions and gaps were consistently larger in lower interference fit implants. Furthermore, simplified loading underestimated micromotions and gaps compared to the complex loading.

Interpretation

These findings help explain why higher interference fits provided limited improvements in primary stability during experimental tests, despite differing predictions from simulations. This study enhances our understanding of bone-implant interactions and suggests that increasing interference fit does not necessarily improve implant stability. It also highlights the importance of incorporating complex loading conditions for more accurate primary stability assessment.

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不同过盈配合下无水泥胫骨构件初级稳定性的有限元分析

背景：无骨水泥膝关节植入物通过干涉配合实现初始固定，其中胫骨植入物被压入一个较小的骨腔。必须仔细平衡种植体和骨切口之间的尺寸，以实现最佳过盈配合，确保良好的初级稳定性，这对于长期固定和成功的骨整合至关重要。然而，理想的过盈配合仍然不确定。过度的过盈配合可能导致骨塑性变形，而不充分的配合可能导致骨-种植体界面的大微运动，小运动，影响稳定性。本研究通过有限元分析评估过盈配合对骨塑性和微运动的影响，以及不同载荷条件对初级稳定性的影响。方法采用有限元模型，模拟了350 μm和700 μm的过盈配合。在简化和复杂载荷条件下，评估步态和深蹲活动时的微运动、间隙动力学和骨变形。高过盈配合会增加骨塑性变形，限制弹性能的积累，而低过盈配合则会降低这种影响。在低过盈配合种植体中，微动和间隙始终较大。此外，与复杂加载相比，简化加载低估了微运动和间隙。这些发现有助于解释为什么在实验测试中，尽管与模拟的预测不同，但较高的干涉拟合对初级稳定性的改善有限。这项研究增强了我们对骨-种植体相互作用的理解，并表明增加过盈配合不一定能提高种植体的稳定性。它还强调了将复杂载荷条件纳入更准确的初级稳定性评估的重要性。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Clinical Biomechanics 医学-工程：生物医学

CiteScore

3.30

自引率

5.60%

发文量

189

审稿时长

12.3 weeks

期刊介绍： Clinical Biomechanics is an international multidisciplinary journal of biomechanics with a focus on medical and clinical applications of new knowledge in the field. The science of biomechanics helps explain the causes of cell, tissue, organ and body system disorders, and supports clinicians in the diagnosis, prognosis and evaluation of treatment methods and technologies. Clinical Biomechanics aims to strengthen the links between laboratory and clinic by publishing cutting-edge biomechanics research which helps to explain the causes of injury and disease, and which provides evidence contributing to improved clinical management. A rigorous peer review system is employed and every attempt is made to process and publish top-quality papers promptly. Clinical Biomechanics explores all facets of body system, organ, tissue and cell biomechanics, with an emphasis on medical and clinical applications of the basic science aspects. The role of basic science is therefore recognized in a medical or clinical context. The readership of the journal closely reflects its multi-disciplinary contents, being a balance of scientists, engineers and clinicians. The contents are in the form of research papers, brief reports, review papers and correspondence, whilst special interest issues and supplements are published from time to time. Disciplines covered include biomechanics and mechanobiology at all scales, bioengineering and use of tissue engineering and biomaterials for clinical applications, biophysics, as well as biomechanical aspects of medical robotics, ergonomics, physical and occupational therapeutics and rehabilitation.