Spatial variation of fixed charge density in knee joint cartilage from sodium MRI – Implication on knee joint mechanics under static loading

Lasse P. Räsänen, Petri Tanska, Mika E. Mononen, Eveliina Lammentausta, Štefan Zbýň, Mikko S. Venäläinen, Pavol Szomolanyi, Corrinus C. van Donkelaar, Jukka S. Jurvelin, Siegfried Trattnig, Miika T. Nieminen, Rami K. Korhonen

Research output: Contribution to journalArticle

8 Scopus citations

Abstract

The effects of fixed charge density (FCD) and cartilage swelling have not been demonstrated on cartilage mechanics on knee joint level before. In this study, we present how the spatial and local variations of FCD affects the mechanical response of the knee joint cartilage during standing (half of the body weight, 13 minutes) using finite element (FE) modeling. The FCD distribution of tibial cartilage of an asymptomatic subject was determined using sodium (23Na) MRI at 7T and implemented into a 3-D FE-model of the knee joint (Subject-specific model, FCD: 0.18±0.08 mEq/ml). Tissue deformation in the Subject-specific model was validated against experimental, in vivo loading of the joint conducted with a MR-compatible compression device. For comparison, models with homogeneous FCD distribution (homogeneous model) and FCD distribution obtained from literature (literature model) were created. Immediately after application of the load (dynamic response), the variations in FCD had minor effects on cartilage stresses and strains. After 13 minutes of standing, the spatial and local variations in FCD had most influence on axial strains. In the superficial tibial cartilage in the Subject-specific model, axial strains were increased up to +13% due to smaller FCD (mean −11%), as compared to the homogeneous model. Compared to the literature model, those were decreased up to −18% due to greater FCD (mean +7%). The findings demonstrate that the spatial and local FCD variations in cartilage modulates strains in knee joint cartilage. Thereby, the results highlight the mechanical importance of site-specific content of proteoglycans in cartilage.

Original languageEnglish (US)
Pages (from-to)3387-3396
Number of pages10
JournalJournal of Biomechanics
Volume49
Issue number14
DOIs
StatePublished - Oct 3 2016
Externally publishedYes

Keywords

  • Articular cartilage
  • Finite element analysis
  • Fixed charge density
  • Knee joint
  • Sodium MRI

Fingerprint Dive into the research topics of 'Spatial variation of fixed charge density in knee joint cartilage from sodium MRI – Implication on knee joint mechanics under static loading'. Together they form a unique fingerprint.

  • Cite this

    Räsänen, L. P., Tanska, P., Mononen, M. E., Lammentausta, E., Zbýň, Š., Venäläinen, M. S., Szomolanyi, P., van Donkelaar, C. C., Jurvelin, J. S., Trattnig, S., Nieminen, M. T., & Korhonen, R. K. (2016). Spatial variation of fixed charge density in knee joint cartilage from sodium MRI – Implication on knee joint mechanics under static loading. Journal of Biomechanics, 49(14), 3387-3396. https://doi.org/10.1016/j.jbiomech.2016.09.011