Tensile mechanical properties of vitrified porcine menisci are superior to frozen and similar to fresh porcine menisci.

Vitrification inhibits crystallization of ice and may allow the mechanical properties of menisci to be preserved for transplantation without the damaging consequences of ice crystals formed during freezing. The primary objective of this study was to investigate the differences between fresh, frozen, and vitrified porcine lateral menisci examining tensile mechanical properties along the circumferential-peripheral, circumferential-central, longitudinal, and radial orientations. The secondary objective was to investigate the variations in the tensile mechanical properties of menisci comparing the circumferential-peripheral orientation to the three other orientations: circumferential-central, longitudinal, and radial. Quasi-static tensile testing was conducted to quantify the tensile mechanical properties of fresh, frozen and vitrified menisci. Ultimate tensile strength of frozen menisci were significantly decreased compared with fresh and vitrified menisci along three orientations: circumferential-peripheral, longitudinal, and radial. Along the circumferential-central orientation, tensile modulus of frozen menisci was significantly decreased compared with fresh menisci. The mechanical properties of vitrified menisci were comparable to fresh menisci along all four orientations. For all menisci (fresh, frozen and vitrified), ultimate tensile strength and failure strain along the circumferential-peripheral orientation were significantly increased compared with the three other orientations. Freezing was detrimental to the mechanical properties of menisci but vitrification likely avoided the negative effects of freezing thereby preserving mechanical properties that were comparable to fresh menisci. The findings of this study revealed that vitrification was superior to freezing for preserving mechanical properties of meniscal tissue; hence, vitrification is likely to be a competitive alternative to freezing for meniscal transplantation in the future.