[Pathogenetic aspects of arthrosis and its therapeutic aspects]

The hitherto accepted idea that articular cartilage is merely bradythrophic tissue which, like a shoe sole, is subjected to continuous wear and tear, as a whole must be revised by considering the growing biochemical, biophysical, and ultrastructural research of the matrix components. The chondrocyte is the single living element of the cartilage: Type-II collagenous fibres and the proteoglycans are its products. To what extent the regulation of collagen production and above all the steady-state regulation is controlled by a superordinating regulation is still not known. However, we must absolutely postulate such. In the mechanics of the joint there are two antagonists which confront each other: 1. the (to a large degree) intellectually regulatable physical strain; and 2. the quality of the cartilage matrix. This represents a refined hydroelastic system. Research into the biochemistry and biophysics continuously provides an increasing abundance of new data on the molecular biological mechanisms, which 1. induce the degradation of proteoglycans and collagens; 2. increase the synthesis of the matrix components; 3. antagonize the degradation, and 4. inhibit the synthesis. In addition, an interaction of these factors can also be expected. Moreover, new information on the components and structures of the matrix is continuously gathered. Up to now, we know of 14 different types of collagen, which on the other hand are accessible to various degradative enzymes. The most important, and--from the standpoint of the biomechanics--the most interesting element/building block is, however, the proteoglycan molecule, whose excessive water-binding capacity enables the hydroelasticity of the hyaline cartilage.(ABSTRACT TRUNCATED AT 250 WORDS)