Affiliations: [a] Department of Pediatrics, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78284 | [b] Rheology Laboratory, Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX 78712
Abstract: Rheological and compositional properties of pathological synovial fluids were measured and compared in order to reveal differences between disease states. The cases include degenerative joint disease, rheumatoid arthritis, mixed connective tissue disease, and pseudo gout. Using an oscillatory flow capillary instrument, measurements were made of both the frequency and shear rate dependence of the complex viscoelasticity. The fluid types differ most in their elasticity, with the degenerative joint disease fluids having the greatest average viscosity, elasticity and intrinsic viscosity, followed by the rheumatoid arthritis fluids, and the fluids from cases of mixed connective tissue disease. Differences in the hyaluronate and protein concentrations are not as great as those between rheological variables. The viscoelasticity of synovial fluid appears more strongly dependent on the degree of polymerization of hyaluronate than on its concentration. These synovial fluids conform well to a model of relaxation process truncation. Distinct types of elastic stres train behavior reveal the nature of the dynamic fluid structure.
