VISCOELASTIC EVALUATION OF DIFFERENT KNEE OSTEOARTHRITIS THERAPIES

This study deals with the viscoelastic evaluation of the efficacy of t wo ordinary knee osteoarthritis therapies: injections of exogenous hig h molecular weight hyaluronic acid and arthrocentesis. The results wer e also compared with ''placebo'' treatment. Synovial fluids were extra cted from osteoarthritic knee joints of 60 patients before and after t he different treatments and were analysed in a rheometer with coaxial cylinders arrangement at 37 degrees C. Frequency sweep experiments pro vided 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 an d hyaluronic acid concentration and molecular weight in pathological s ynovial fluids.