Physical indicators of cartilage health: the relevance of compliance, thickness, swelling and fibrillar texture

Abstract

This study uses a bovine patella model to compare the relative merits of on-bone compliance and thickness measurements, free-swelling behaviour, and structural imaging with differential interference contrast (DIC) light microscopy to assess the biomechanical normality of the cartilage matrix. The results demonstrate that across a spectrum of cartilage tissues from immature, mature, through to mildly degenerate, and all with intact articular surfaces, there is a consistent pattern of increased free swelling of the isolated general matrix with age and degeneration.High swelling was always associated with major structural alterations of the general matrix that were readily imaged using DIC light microscopy. Conversely, for all tissue groups, no relationship was observed between thickness vs. compliance and compliance vs. general matrix swelling. Only in the proximal aspects of the normal mature and degenerate tissues was there a correlation between thickness and general matrix swelling. Free-swelling measurements combined with fibrillar texture imaging using DIC light microscopy are therefore recommended as providing a reliable and quick method of assessing the biomechanical condition of the cartilage general matrix.

Influence of an Initiating Microsplit on the Resistance to Compression-Induced Rupture of the Articular Surface

“…This coupling is strongly dependent on the ability of the collagenous network to contain the high-swelling proteoglycans. Any reduction in network interconnectivity lessens this containment and allows the general matrix to swell abnormally, both transversely and radially [12,13,20,21]. The greater average thickness of cartilage of the degenerate tissues compared with that with the healthy tissues shown both in this study and in earlier studies [12,[22][23][24][25], also is consistent with a reduction in this level of coupling.…”

“…Visible disruption of the AS is generally recognized as an indicator of early osteoarthritic degeneration [10,11]. However, even where there is no detectable disruption of the AS, there can be major structural changes occurring in the underlying general matrix [12,13]. Such changes in the deeper matrix may be reflected in changes occurring in the AS which may, in turn, lead to its weakening but not necessarily its visible disruption.…”

Primary cilia in osteoarthritic chondrocytes: From chondrons to clusters

“…The study used mature bovine patella articular cartilage (Broom et al, 2001;Broom and Flachsmann, 2003;Thambyah and Broom, 2007) that correlated well with the progressive stages of the disease reported in human degenerative OA (Buckwalter and Mankin, 1998b). This progression included cartilage softening, fibrillation, fissures, and chondrocyte clustering.…”

DT-MRI Based Computation of Collagen Fiber Deformation in Human Articular Cartilage: A Feasibility Study

“…There is also considerable interest in determining the structural arrangement of collagen fibers nondestructively. Methods to accomplish this include differential interference contrast light microscopy, 10 Small Angle X-ray Scattering (SAXS), 45,46,48 Optical Coherence Tomography (OCT) and polarization sensitive optical coherence tomography (PS-OCT), 61,62 spin-spin relaxation time T2-weighted Magnetic Resonance Imaging (T2w MRI) 16,71 and high field Diffusion Tensor MRI (DT-MRI). 16,17,20,44 MRI is certainly the most advanced and widely used in vivo imaging technique for cartilage.…”