title: Use of polarized light for quantitative determination of the adjustment of the tangential fibres in articular cartilage.
abstract: According to recent research the course of the tangential fibres is gaining increasing importance for the analysis of the first signs of pathological alterations in the articular cartilage. In a model-test, parallel-running synthetic double-refracting filaments, rotated between polarisator and analysator at right angles to each other effect an extinction curve which has two maxima at 45 degrees and the minimum at 0 degrees. Crossing filaments at different angles effects curves which are specific for the different angles in such a manner that with increasing angles to 45 degrees the curves approximate to a horizontal line. On the other hand the course of the different curves make it possible to determine corresponding angles. Then the same method is used to estimate the mean crossing-angles of tangential fibres in histological sections of articular cartilage with masked collagen fibres. The method is suitable for a quantitative calculation of the crossing-angles between 0 degrees and 45 degrees, which cannot be defined by the split-line method of Hultkrantz. In contrast to the conditions of the scanning electron microscope, the integrating nature of the polarized light is advantageous because it permits analysis of a more extensive visual field. From comparisons with the test model, a considerable variety of crossing angles of tangential fibres in the cartilage can be shown to exist.
mesh_terms: D000368:Aged; D001718:Birefringence; D002358:Cartilage, Articular / Q000648:ultrastructure*; D003094:Collagen; D005260:Female; D006801:Humans; D008297:Male; D008859:Microscopy, Polarization / Q000379:methods; D008875:Middle Aged
chemical_list: D003094:Collagen