A serial multiparametric quantitative magnetic resonance imaging study to assess proteoglycan depletion of human articular cartilage and its effects on functionality

Scientific Reports, vol. 10, pp. 15106

Abstract

Water, collagen, and proteoglycans determine articular cartilage functionality. If altered, susceptibility to premature degeneration is increased. This study investigated the effects of enzymatic proteoglycan depletion on cartilage functionality as assessed by advanced Magnetic Resonance Imaging (MRI) techniques under standardized loading. Lateral femoral condylar cartilage-bone samples from patients undergoing knee replacement (n = 29) were serially imaged by Proton Density-weighted and T1, T1ρ, T2, and T2* mapping sequences on a clinical 3.0 T MRI scanner (Achieva, Philips). Using pressure-controlled indentation loading, samples were imaged unloaded and quasi-statically loaded to 15.1 N and 28.6 N, and both before and after exposure to low-concentrated (LT, 0.1 mg/mL, n = 10) or high-concentrated trypsin (HT, 1.0 mg/mL, n = 10). Controls were not treated (n = 9). Responses to loading were assessed for the entire sample and regionally, i.e. sub- and peri-pistonally, and zonally, i.e. upper and lower sample halves. Trypsin effects were quantified as relative changes (Δ), analysed using appropriate statistical tests, and referenced histologically. Histological proteoglycan depletion was reflected by significant sub-pistonal decreases in T1 (p = 0.003) and T2 (p = 0.008) after HT exposure. Loading-induced changes in T1ρ and T2* were not related. In conclusion, proteoglycan depletion alters cartilage functionality and may be assessed using serial T1 and T2 mapping under loading.

Authors 10

1. Tobias Hafner Aachen Department of Diagnostic and Interventional Radiology

   Universitätsklinikum Aachen

   Affiliation as printed

   Department of Diagnostic and Interventional Radiology, Aachen University Hospital, Aachen, Germany

2. Justus Schock Aachen Institute of Computer Vision and Imaging

   RWTH Aachen University · Düsseldorf University Hospital

   Affiliation as printed

   Institute of Computer Vision and Imaging, RWTH University Aachen, Aachen, Germany

   Medical Faculty, Department of Diagnostic and Interventional Radiology, University Hospital Düsseldorf, Moorenstraße 5, 40225, Dusseldorf, Germany

3. Manuel Post Aachen Department of Diagnostic and Interventional Radiology

   Universitätsklinikum Aachen

   Affiliation as printed

   Department of Diagnostic and Interventional Radiology, Aachen University Hospital, Aachen, Germany

4. Daniel Benjamin Abrar

   Düsseldorf University Hospital

   Affiliation as printed

   Medical Faculty, Department of Diagnostic and Interventional Radiology, University Hospital Düsseldorf, Moorenstraße 5, 40225, Dusseldorf, Germany

5. Philipp Sewerin

   Düsseldorf University Hospital · Heinrich Heine University Düsseldorf

   Affiliation as printed

   Medical Faculty, Department and Hiller-Research-Unit for Rheumatology, University Hospital Düsseldorf, Düsseldorf, Germany

6. Kevin Linka

   Hamburg University of Technology

   Affiliation as printed

   Department of Continuum and Materials Mechanics, Hamburg University of Technology, Hamburg, Germany

7. Matthias Knobe

   Luzerner Kantonsspital

   Affiliation as printed

   Clinic for Orthopaedic and Trauma Surgery, Cantonal Hospital Luzern, Luzern, Switzerland

8. Christiane Katharina Kuhl Aachen Department of Diagnostic and Interventional Radiology

   Universitätsklinikum Aachen

   Affiliation as printed

   Department of Diagnostic and Interventional Radiology, Aachen University Hospital, Aachen, Germany

9. Daniel Truhn Aachen Department of Diagnostic and Interventional Radiology

   Universitätsklinikum Aachen

   Affiliation as printed

   Department of Diagnostic and Interventional Radiology, Aachen University Hospital, Aachen, Germany

10. Sven Nebelung

    Düsseldorf University Hospital

    Affiliation as printed

    Medical Faculty, Department of Diagnostic and Interventional Radiology, University Hospital Düsseldorf, Moorenstraße 5, 40225, Dusseldorf, Germany. sven.nebelung@med.uni-duesseldorf.de

    Medical Faculty, Department of Diagnostic and Interventional Radiology, University Hospital Düsseldorf, Moorenstraße 5, 40225, Dusseldorf, Germany