The authors observed morphological changes with light microscopy and scanning electron microscopy. of 8 patients with osteoarthritis caused by avascular necrosis whose articular cartilage of femoral head was classified by the degree of injury.
In light microscopy, the articular cartilage of stage II patient appeared homogenous in structure, composed of a dense ground substance and chondrocytes. But in the other patients of stage II could be visualized partial degenerative change and
loss of
articular surface and chondrocytes.
In the case of stage III, the chondrocyte cluster could be seen just underneath the surface which enabled us to observe and irregular articular surface. The number of chondrocytes were also increased on the superficial and middle portions.
In the case of stage IV, severe degenerative change of articular cartilage and subchondral bone were observed.
In the mild osteoarthritic articular cartilage, there were observed marked ultrastructural differences in the articular surface, the subsurface fibrillar framework of the matrix and chondrocytes. It was estimated that the organization of collagen
fibrils in articular cartilage shows a three-dimensional netmork with a special system in each zone.
In the sever osteoarthritic cartilage, it is observed degenerated chondroid materials, destroyed and irregular oricnted collagen fibers and amorphous conglomeration.
In the mild osteoarthritic articular cartilage, chondrocytes and well-defined lacunae are observed. The gap between the chondrocyte and the lacunae wall is preserved.
These results indicate that osteoarthritis caused by avascular necrosis of femoral head is initially developed from minor disruption of ultrastructural collagen fibrils due to an excessive tensile stressed than eventually progressed to
osteoarthritis.
The results of this study was acquired from a small nmber of specimens but such a study may provides very helpful information in the analysis of other disease related to articular cartilage if similar continued research is carried out in the
future
as
there are few reports as yet published on the morphological structure of articular cartilage.
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