Towards preservation of the natural knee: State-of-the-art approaches to understand the kinematics and tissue mechanics of human menisci in vivo.

半月板损伤是第二常见的膝关节损伤，导致关节变性和活动问题。为了通过人工半月板的开发来保护自然膝关节，本研究的目的是研究人类膝关节半月板在日常生活动态活动中的运动学和组织力学。这项研究的新颖之处在于，在完整的步态周期中，结合受试者特定的建模，在体内研究膝关节半月板，而不是在体外使用尸体半月板或在体内使用功能MRI进行静态负重研究。换句话说，我们将首次在生理学相关的运动学条件下分析膝关节半月板运动学和材料力学，包括步态的加载和卸载阶段。这种新的认识将通过开发结合先进成像和计算建模方法的新方法创新来促进。为了获得先进的图像，PI将与项目合作伙伴合作，使用最近完成的高频跟踪双面透视系统以目前尚不可能实现的分辨率评估关节运动学。为了确保最高水平的准确性，将使用瑞士医学成像中心（SCMI）最先进的医学成像设备，特别是7特斯拉磁共振成像（MRI）系统和光子计数计算机断层扫描（CT），这是欧洲首个此类设备。最高质量的图像将形成膝关节有限元模型的基础，包括具有高级材料表示的半月板。我们的研究将基于膝关节半月板在完整步态周期中的功能运动和应变模式，对膝关节半月板运动学和材料力学产生新的综合理解。本项目对自然半月板生理功能的新研究成果的翻译将直接指导半月板植入物设计的进一步发展，包括新型植入物材料，并促进生物力学研究的新领域，以改善自然膝关节的保护。

Meniscal injuries are the second most common injury to the knee, leading to joint degeneration and mobility issues. Towards the preservation of natural knees through the development of artificial menisci, the aim of this research is to investigate kinematics and tissue mechanics of human knee joint menisci in the living body during dynamic activities of daily living. The novelty of this study is the in vivo investigation of knee joint menisci during complete gait cycles combined with subject-specific modelling rather than investigation using cadaveric menisci in vitro or functional MRI for static weight-bearing in vivo. In other words, we will analyse knee joint menisci kinematics and material mechanics for the first time under physiologically relevant kinematic conditions, including both the loaded and unloaded phases of gait. This new understanding will be facilitated by developing new methodological innovations that combine advanced imaging and computational modelling methods. To acquire the advanced images, the PI will collaborate with the project partner, using the recently completed high-frequency tracking dual-plane fluoroscopy system to assess joint kinematics at a resolution that has not been possible until now. To ensure the highest levels of accuracy available, the state-of-the-art medical imaging facilities at the Swiss Centre for Medical Imaging (SCMI), Balgrist Campus, Zürich, will be used, specifically the 7 Tesla Magnetic Resonance Imaging (MRI) system and photon-counting Computer Tomography (CT), which is the first of its kind in Europe. Images of the highest quality available will then form the basis for the development of finite element models of the knee joints, including menisci with a advanced material representations.Our research will generate a new combined understanding of knee joint meniscal kinematics and material mechanics, based on their functional movement and strain patterns during complete gait cycles. Translation of novel research findings on the physiological functionality of the natural menisci from this project will directly guide the further development of meniscal implant designs, including novel implant materials, and foster a new field of biomechanical investigation into improving the preservation of natural knees.