Collagen Framework of Human Articular Cartilage Studied by the Replica Method and Scanning Electron Microscopy

Abstract

1. Collagen frameworks of articular cartilages on the split-surface were divided into four parts. In layer 1, collagen fibers of about 600Å in diameter ran parallel to the articular surface; in zone 2 very fine fibers (200Å) were oriented in various directions; in zone 3 slightly thicker fibers (400Å) ran in bundles and crossed over each other; and in zone 4 thick fibers of 600-800Å descended vertically to the surface.
2. Collagen fibers of the articular cartilage were observed being produced mainly in zones 2 and 3. Around the circumference of the cell, fine fibers were arranged radiately and increased their diameter as they were further detached from the cell.
3. The patterns of the arrangement of collagen fibers on the surface of articular cartilage varied even in the same joint depending on different sites examined. Peroidic cross banding of collagen fibers was not recognized on the adult joint surface, but it was often clear in foetal joints which were relatively free from mechanical stress.
4. Articular surface in patients with rheumatoid arthritis and arthritis tuberculosa were observed.