title: Patellar chondropathy. II. Ultrastructure, scanning electron microscopic studies.
abstract: A scanning electron microscopic study of the chondropathy of the patellar articular surfaces following knee injury was made. The early signs of degeneration were evident in the superficial membrane. Here, the fibres running parallel with the surface then turning deep become irregularly arranged, i.e. the amount of matrix embedding the fibres was reduced and the uncovered fibres became fragmented causing degeneration of the superficial membrane. During the progressive pathological process, as a result of the gradual deterioration of the interterritorial substance of the uncovered hyaline cartilage, spaces, fissures and deep pits were formed in the upper, then the lower, articular layers. The degeneration involved also the chondrons. With the disintegration of the chondrons the external and internal cell areolae disappear, the cell nests of chondrocytes are opened and the cells degenerate. Finally, the irregular cellular and fibrous structures and their remnants as well as the elements of connective tissue proliferation initially associated with the degenerative process can be visualized ultrastructurally.
mesh_terms: D002357:Cartilage Diseases / Q000473:pathology*; D002358:Cartilage, Articular / Q000648:ultrastructure; D006801:Humans; D008855:Microscopy, Electron, Scanning; D010329:Patella / Q000648:ultrastructure*