Effect of Therapeutic Pulsed Ultrasound in Dogs with Experimental Stifle Joint Osteoarthritis

The purpose of this study was to investigate the effect of therapeutic ultrasound upon some functional parameters in dogs with stifle joint osteoarthritis. Experimental osteoarthritis was induced in 6 mixedbreed dogs by injections of sodium monoiodoacetate in the left knee joint. The right joint served as control. The clinical and goniometric status of dogs was monitored at post injections days 1, 30, 60, 105 and 130. Therapeutic ultrasound was applied between days 105 and 130 using a 1 cm transducer, 3 MHz frequency, power density 1.20 W/cm2 and a pulsed wave duty cycle of 1/2 (impulse time/interval). Nine procedures were performed. Synovial fluid viscosity was also improved without alterations of its volume. Therapeutic ultrasound improved the clinical status, increased the muscle mass of the affected limb, the motility but not the circumference of the osteoarthritic knee joint in dogs. This physical factor had a beneficial effect on physicochemical properties of synovial fluid. At the same time, ultrasound therapy did not influence the chronic fibrous alterations in soft tissues.