[Biorheological contribution to the problem of rheumatic joint diseases]

The rheological properties of synovial fluids from patients with different rheumatic diseases are discussed. Viscosities of 73 samples were determined and are compared to a standard of "healthy" human synovial fluid p. m. and to bovine synovia. Typical differences between "healthy", degenerative and inflammatory synovial fluids could be discerned. These differences can be characterized with several rheological parameters. The mechanism of lubrication in joints and the role of synovial fluid as a lubricant are discussed. Rheological properties of polymere solutions which could serve as a substitute for sick synovial fluids are described and compared to the properties of healthy synovia. Several possibilities for molecular changes which could account for the deterioration of synovial fluids in patients with different rheumatic diseases are discussed.