The Submicroscopic Structure of Articular Cartilage in the Adult pig

Abstract

Horky D.: The Submicroscopic StrUCture of Articular Cartilage in the Adult Pig. Acta vet. Bmo, 62,1993: 9-18. Articular cartilage collected from the femoral heads of 5 adult pigs of both sexes,_ aged 14-24 months, was studied by light microscopy and transmission and scanning electron microscopy.. . Chondrocytes of the surface layer were oval in shape and sent out short projections into the surrounding pericellular matrix. Their cytoplasm contained numerous lysosomes, transport vacuoles, centrioles and a well·formed Golgi apparatus and small deposits of glycogen. They were arranged in rows or tiers.Chondrocytes of the middle layer were oval cells enclosed by pairs in lacunae. Their nuclei had 1-2 nucleoli of reticular type. The zonula nucleum limitans was well developed. The cytoplasm contained a large number of mitochondria, cisternae of the granular endoplasmic reticulum, a large Golgi field, numerous transport vacuoles, lysosomes and conspicuous glycogen deposits.In the transitional zone, chondrocytes were arranged in tiers perpendicular to the surface. They were smaller in size and the cytoplasm contained, apart from the typical organelles, large bundles of intermediate filaments. Chondrocytes of the deep layer could be distinguished into those characterized by conspicuously large lipid vacuoles and those with homogeneous cytoplasm and small glycogen deposits.The pericellular matrix was well developed in the majority of chondrocytes; in the regions where it was missing the cell membrane was in contact with the intercellular matrix. In the middle layer, cell detritus was seen at the border between pericellular and intercellular matrix Submicroscopic structure, articular cartilage, adult swine Articular cartilage is an avascular, alymphatic and aneural tissue lining the articular bonesurface. Like other connective tissues it consists of cells -chondrocytes -deposited in an abun-· dance of the intercellular matrix. The chondrocytes account for only 0.01-0.1 % of the total cartilage volume. The intercellular matrix is made up of collagenous fibres, proteoglycans, and. organic and inorganic components. A proper function of the articular cartilage depends on its mechanical properties permitting it to a) transfer and distribute high pressure forces upon the subchondral bone; b) maintain the constant load at a relatively low level; c) facilitate movementat minimal friction (Wright

Submicroscopic Structure of Equine Articular Cartilage

“…The deep layer of articular cartilage showed a structure similar to this layer of articular cartilage in other mammals (Hedlung et al 1993;Hork˘ 1991cHork˘ , 1993aHork˘ , 1994b.…”

Scanning Electrochemical Microscopy as a Local Probe of Oxygen Permeability in Cartilage

“…A number of studies have been made on the bulk diffusion of solutes through cartilage (Maroudas, 1970;Bernich et al, 1976;Roberts et al, 1996;Torzilli et al, 1997Torzilli et al, , 1998. However, it is known that cartilage is structurally heterogeneous, evident from various microscopy studies (Horky, 1993;Jurvelin et al, 1996). Some workers have addressed this issue by taking samples (50 -200 m thick) at varying depths from the articular surface (Bernich et al, 1976;Torzilli et al, 1997Torzilli et al, , 1998, but data were still averaged across the surface of the slice, thereby neglecting any lateral inhomogeneities in transport rates.…”