Magnetic resonance imaging of human knee joint functionality under variable compressive in-situ loading and axis alignment

Philipp Schad; Maximilian Wollenweber; Johannes Thüring; Justus Schock; Jörg Eschweiler; Giulia Palm; Klaus Radermacher; Felix Eckstein; Andreas Prescher; Christiane Kuhl; Daniel Truhn; Sven Nebelung

doi:10.1016/j.jmbbm.2020.103890

Magnetic resonance imaging of human knee joint functionality under variable compressive in-situ loading and axis alignment

J Mech Behav Biomed Mater. 2020 Oct:110:103890. doi: 10.1016/j.jmbbm.2020.103890. Epub 2020 May 30.

Authors

Affiliations

¹ Department of Diagnostic and Interventional Radiology, Aachen University Hospital, Aachen, Germany.
² Institute of Diagnostic and Interventional Radiology, University Hospital Düsseldorf, Düsseldorf, Germany; Institute of Computer Vision and Imaging, RWTH Aachen University, Aachen, Germany.
³ Department of Orthopaedic Surgery, Aachen University Hospital, Aachen, Germany.
⁴ Helmholtz-Institute for Biomedical Engineering, Chair of Medical Engineering, RWTH Aachen University, Aachen, Germany.
⁵ Department of Imaging & Functional Musculoskeletal Research, Institute of Anatomy & Cell Biology, Paracelsus Medical University Salzburg & Nuremberg, Salzburg, Austria; Chondrometrics GmbH, Ainring, Germany; Ludwig Boltzmann Institute for Arthritis and Rehabilitation, Paracelsus Medical University, Salzburg, Austria.
⁶ Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Aachen, Germany.
⁷ Department of Diagnostic and Interventional Radiology, Aachen University Hospital, Aachen, Germany; Institute of Computer Vision and Imaging, RWTH Aachen University, Aachen, Germany.
⁸ Institute of Diagnostic and Interventional Radiology, University Hospital Düsseldorf, Düsseldorf, Germany. Electronic address: sven.nebelung@med.uni-duesseldorf.de.

PMID: 32957197
DOI: 10.1016/j.jmbbm.2020.103890

Abstract

Magnetic resonance imaging (MRI) under mechanical loading, commonly referred to as stress MRI, allows the evaluation of functional properties of intra- and periarticular tissues non-invasively beyond static assessment. Quantitative MRI can identify physiological and pathological responses to loading as indication of, potentially treatable, early degeneration and load transmission failure. Therefore, we have developed and validated an MRI-compatible pressure-controlled axial loading device to compress human knee specimens under variable loading intensity and axis deviation. Ten structurally intact human knee specimens (mean age 83.2 years) were studied on a 3.0T scanner (Achieva, Philips). Proton density-weighted fat-saturated turbo spin-echo and high-resolution 3D water selective 3D gradient-echo MRI scans were acquired sequentially at 10° joint flexion in seven configurations: unloaded and then at approximately half and full body weight loading in neutral, 10° varus and 10° valgus alignment, respectively. Following manual segmentation in both femorotibial compartments, cartilage thickness (ThC) was determined as well as meniscus extrusion (ExM). These measures were compared to computed tomography scans, histological grading (Mankin and Pauli scores), and biomechanical properties (Instantaneous Young's Modulus). Compartmental, regional and subregional changes in ThC and ExM were reflective of loading intensity and joint alignment, with the greatest changes observed in the medial compartment during varus and in the lateral compartment during valgus loading. These were not significantly associated with the histological tissue status or biomechanical properties. In conclusion, this study explores the physiological in-situ response of knee cartilage and meniscus, based on stress MRI, and as a function of loading intensity, joint alignment, histological tissue status, and biomechanical properties, as another step towards clinical implementation.

Keywords: Cartilage; Functionality; Loading device; Mechanical axis; Meniscus; Stress MRI.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Aged, 80 and over
Biomechanical Phenomena
Cartilage, Articular*
Humans
Knee Joint* / diagnostic imaging
Magnetic Resonance Imaging
Pressure
Weight-Bearing