Compressive Properties and Hydraulic Permeability of Human Meniscus: Relationships With Tissue Structure and Composition

Abstract

The meniscus is crucial in maintaining knee function and protecting the joint from secondary pathologies, including osteoarthritis. The meniscus has been shown to absorb up to 75% of the total load on the knee joint. Mechanical behavior of meniscal tissue in compression can be predicted by quantifying the mechanical parameters including; aggregate modulus (H) and Poisson modulus (ν), and the fluid transport parameter: hydraulic permeability (K). These parameters are crucial to develop a computational model of the tissue and for the design and development of tissue engineered scaffolds mimicking the native tissue. Hence, the objective of this study was to characterize the mechanical and fluid transport properties of human meniscus and relate them to the tissue composition. Specimens were prepared from the axial and the circumferential anatomical planes of the tissue. Stress relaxation tests yielded the H, while finite element modeling was used to curve fit for ν and K. Correlations of moduli with water and glycosaminoglycans (GAGs) content were investigated. On average H was found to be 0.11 ± 0.078 MPa, ν was 0.32 ± 0.057, and K was 2.9 ± 2.27 × 10−15 m4N−1s−1. The parameters H, ν, and K were not found to be statistically different across compression orientation or compression level. Water content of the tissue was 77 ± 3.3% while GAG content was 8.79 ± 1.1%. Interestingly, a weak negative correlation was found between H and water content (R2 ~ 34%) and a positive correlation between K and GAG content (R2 ~ 53%). In conclusion, while no significant differences in transport and compressive properties can be found across sample orientation and compression levels, data trends suggest potential relationships between magnitudes of H and K, and GAG content.

Yucatan Minipig Knee Meniscus Regional Biomechanics and Biochemical Structure Support its Suitability as a Large Animal Model for Translational Research

“…Radial stiffness of minipig menisci were on par to those of human menisci; values averaged across both medial and lateral menisci and regions were 8.3 MPa for the minipig and 10.8 MPa for humans ( Tissakht and Ahmed, 1995 ) ( Figure 4C ). In terms of compressive properties, only permeability was significantly different between medial and lateral menisci; this difference between menisci was not seen in human tissue in a study that measured compressive properties using stress-relaxation ( Morejon et al, 2021 ). Additionally, the homogeneity seen among regions in Yucatan minipig menisci ( Figure 5 ) is not reflected in the human, albeit a similar trend was identified; the anterior region of the human medial meniscus is stiffer than its central and posterior regions, and is 80% as stiff as the anterior region of the medial meniscus in the Yucatan minipig ( Sweigart et al, 2004 ).…”

“…All data are presented as means ± standard deviations. Statistical significance is indicated by bars not sharing the same letters within the same meniscus; additionally, horizontal dotted lines on the Y-axis represent human meniscus values from the literature for comparison to the minipig (Sweigart et al, 2004;Makris et al, 2011;Morejon et al, 2021). were no significant differences in tensile stiffness and strength in the circumferential or radial directions between medial and lateral menisci (Figure 4).…”

Meniscus Regeneration With Multipotent Stromal Cell Therapies

“…It also serves as a shock absorber and secondary stabilizer with a possible role in joint lubrication and proprioception ( Makris et al, 2011 ). It has been reported that the meniscus is highly heterogeneous in cellular and extracellular matrix composition, as well as biomechanical properties ( Morejon et al, 2020 ). The structural integrity and biological function would be impaired due to meniscus lesion, which ultimately lead to the deterioration of the joint and accelerate the development of osteoarthritis for the excessive concentrated forces adding on the articular cartilage ( Danso et al, 2017 ).…”

Osteoarthritis-Related Degeneration Alters the Biomechanical Properties of Human Menisci Before the Articular Cartilage

“…On the one hand, studies have shown an increased OA incidence in knees affected by meniscal injuries ( Lohmander et al, 2007 ; Englund, 2009 ). On the other hand, degenerated knee joints also indicate degenerative changes of the menisci, including tears, macerations, and tissue loss ( Bhattacharyya et al, 2003 ; Hunter et al, 2006 ; Englund et al, 2009 ), thereby leading to controversy in the treatment of knee joint OA, as summed up by Englund et al (2009) : “A meniscal tear can lead to knee OA, but knee OA can also lead to a meniscal tear.” Both articular cartilage (AC) ( Silvast et al, 2009 ; Marchiori et al, 2019 ; Ebrahimi et al, 2020 ) and menisci ( Fithian et al, 1990 ; Fox et al, 2012 ; Son et al, 2013 ; Danso et al, 2017 ; Travascio et al, 2020a , b ; Warnecke et al, 2020 ; Morejon et al, 2021 ) are highly anisotropic and inhomogeneous tissues that exhibit strong structure–function relationships that change during the course of OA degeneration. It is well accepted that biomechanical factors like altered joint loading caused by obesity and joint malalignment, trauma, or instability contribute substantially to the initiation and progression of knee joint OA ( Hochberg et al, 1995 ; Jackson et al, 2004 ; Lohmander et al, 2007 ; Englund, 2010 ; Guilak, 2011 ; Willinger et al, 2019 ).…”