Investigation on the Differences in the Mechanical Properties of Fresh, Frozen, and Vitrified Porcine Menisci

• Author / Creator

  Sun, Junran

• The medial and lateral menisci are two semilunar-shaped fibrocartilaginous tissues in the knee that serve multiple important biomechnical functions. While removal of the menisci leads to progressive degenerative changes in the knee, meniscal transplantation is explored to restore normal knee biomechanics. Preservation and long-term storage of meniscal allografts would improve the availability of the tissue for transplantation. One of the most common meniscal preservation approaches in clinical practice is freezing, but it has the limitation of destroying viable cells and causing tissue deformation due to the formation of ice crystals. On the other hand, vitrification, the transformation of an aqueous solution into a non-crystalline amorphous solid without nucleating ice during the cooling and warming process, is being explored. Numerous studies in the literature have quantified the mechanical properties of the meniscal tissue under tension and compression. Nevertheless, the majority of the studies have concentrated on the comparison of the tensile mechanical properties along the longitudinal and radial orientations, and there have been no published studies exploring the effect of vitrification on either the tensile or compressive mechanical properties of the meniscal tissue to date. Therefore, the primary objective of this research is to investigate the differences in the tensile mechanical properties along the circumferential-peripheral, circumferential-central, longitudinal, and radial orientations and the compressive mechanical properties in the axial direction of fresh, frozen, and vitrified porcine lateral menisci. The secondary objective of this research is to investigate the variations in the tensile mechanical properties of the meniscus along the four different orientations (i.e. circumferential-peripheral, circumferential-central, longitudinal, and radial). Quasi-static tensile testing and unconfined compressive stress-relaxation testing were conducted to quantify the mechanical properties of fresh, frozen, and vitrified porcine lateral menisci. One-way analysis of variance (ANOVA) with linear contrasts was performed for the evaluation of statistical significance and a p-value <0.05 was accepted as significant. Experimental results indicated that fresh and vitrified menisci exhibit comparable mechanical properties, whereas frozen menisci exhibit inferior mechanical properties in comparison with fresh and vitrified menisci. Furthermore, superior ultimate tensile stress and failure strain were found along the circumferential-peripheral orientation, while inferior ultimate tensile stress and tensile modulus were found along the radial orientation. Besides, the mean tensile modulus along the circumferential (central and peripheral) and longitudinal orientations are approximately twofold to fourfold higher than that along the radial orientation. The findings of this research revealed that vitrification is superior to freezing in preserving mechanical properties of the meniscal tissue, vitrification is hence likely to be a competitive alternative to freezing for meniscal transplantation in the future.

• Subjects / Keywords

  • vitrification of menisci
  • mechanical properties of porcine menisci
  • meniscal preservation methods
  • orientational variations of menisci

• Graduation date

  Fall 2020

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-9760-n274

• License

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