Functional properties of native and tissue‐engineered cartilage toward understanding the pathogenesis of chondral lesions at the knee: A bovine cadaveric study

Abstract

Chondral lesions frequently occur in different topographic locations of the knee. This study evaluated the functional properties among the articulating surfaces of the tibiofemoral and patellofemoral joints, and whether neo-cartilage engineered using chondrocytes from different knee locations would reflect these differences. The biomechanical properties of bovine cartilage isolated from eight locations within the tibiofemoral (medial and lateral condyle, medial and lateral tibial plateau) and patellofemoral joints (medial and lateral trochlea, medial and lateral patella) were examined. Tensile Young's moduli (tensile moduli) and aggregate moduli of the medial condyle were lower than those of the medial tibial plateau (6.11 ± 0.89 MPa vs. 7.19 ± 1.05 MPa, p = 0.04 and 354.4 ± 38.3 kPa vs. 419.4 ± 31.3 kPa, p = 0.002, respectively). Patella tensile and compressive moduli were lower than the trochlea (4.79 ± 2.01 MPa vs. 6.91 ± 2.46 MPa, p = 0.01 and 337.4 ± 37.2 kPa vs. 389.1 ± 38.3 kPa, p = 0.0005, respectively). Furthermore, chondrocytes from the above locations were used to engineer neo-cartilage, and its respective properties were evaluated. In neo-cartilage, medial condyle tensile and aggregate moduli were lower than in the medial tibial plateau (0.96 ± 0.23 MPa vs. 1.31 ± 0.31 MPa, p = 0.02, and 115.8 ± 26.0 kPa vs. 160.8 ± 18.8 kPa, p = 0.001, respectively). Compared to trochlear chondrocytes, neo-cartilage formed from patellar chondrocytes exhibited lower tensile and compressive moduli (1.16 ± 0.27 MPa vs. 0.74 ± 0.25 MPa, p < 0.001, and 109.1 ± 24.0 kPa vs. 82.5 ± 18.1 kPa, p < 0.001). A significant degree of disparity in biomechanical properties of the opposing articular surfaces was detected; the medial condyle and patella exhibited inferior properties compared to the opposing medial tibial plateau and trochlea, respectively. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2452-2464, 2017.

Non‐destructive detection of matrix stabilization correlates with enhanced mechanical properties of self‐assembled articular cartilage

“…Non‐destructive optical parameter FLIm CH1 LT was significantly increased with +LOX treatment (g) and FLIm CH3 LT was significantly increased with +LOX and + LOX + LINK (h) over CTL. Red dashed lines represent native values (Paschos, Lim, Hu, & Athanasiou, ) [Colour figure can be viewed at wileyonlinelibrary.com]…”

“…Neocartilage constructs with +LOX and +LINK treatments had tensile properties on par with those of native, juvenile femoral cartilage, and the compressive relaxation modulus reached 86% of native values (300 kPa compared with 350 kPa for the native tissue; Paschos et al, ). The lower proteoglycan content at 4 weeks in culture (~7% in neocartilage as compared with ~14% in native tissue; Paschos et al, ) may partially account for lower compressive stiffness.…”

“…Neocartilage constructs with +LOX and +LINK treatments had tensile properties on par with those of native, juvenile femoral cartilage, and the compressive relaxation modulus reached 86% of native values (300 kPa compared with 350 kPa for the native tissue; Paschos et al, ). The lower proteoglycan content at 4 weeks in culture (~7% in neocartilage as compared with ~14% in native tissue; Paschos et al, ) may partially account for lower compressive stiffness. Self‐assembled neocartilage has been shown to increase in proteoglycan content and compressive properties over longer in vitro (Ofek et al, ) and in vivo (Responte, Arzi, Natoli, Hu, & Athanasiou, ) culture periods suggesting the possibility that full biomechanical functionality is achievable.…”

The role of biomaterials in the treatment of meniscal tears

“…Withstand in vivo forces during the joint movement operation (mechanical and structural stability of the biomaterial in the meniscus area needs to be able to withstand compressive and tensile forces (these forces have been aptly described in Paschos et al (2017) );…”

Update on mesenchymal stem cell therapies for cartilage disorders

“…Cartilage lesions are among the most often recognized pathologies in young adults undergoing arthroscopy. Approximately 60% of the patients treated arthroscopically for any reason had at least one chondral lesion at their knee[ 1 ]. Due to the relatively young age of these patients (mean age ranged from 37 to 43 years old) and because the majority of lesions has been graded as II or III, it was suggested that impending osteoarthritis would be inevitable without treatment in these patients[ 1 ].…”