VISCOELASTIC EVALUATION OF DIFFERENT KNEE OSTEOARTHRITIS THERAPIES

This study deals with the viscoelastic evaluation of the efficacy of two ordinary knee osteoarthritis therapies: injections of exogenous high molecular weight hyaluronic acid and arthrocentesis. The results were also compared with ''placebo'' treatment. Synovial fluids were extracted from osteoarthritic knee joints of 60 patients before and after the different treatments and were analysed in a rheometer with coaxial cylinders arrangement at 37 degrees C. Frequency sweep experiments provided the values of shear storage modulus G' and shear loss modulus G'' as function of oscillation frequency. The quantified viscoelasticity gave information about the mechanical performance of synovial fluids and hence the long-term efficacy of osteoarthritis therapies. Moreover, the results were interpreted in terms of macromolecular structure and hyaluronic acid concentration and molecular weight in pathological synovial fluids.