The effectiveness of therapeutic ultrasound to the mechanically damaged chondrocyte culture.

Objective: This study aimed to evaluate the efficacy of low intensity (0.1-0.8 Watt/cm) pulsed ultrasound on chondrocyte cell proliferation and migration.

Methods: Low-intensity pulsed ultrasound (frequency 3 MHz, duty cycle 25%, and pulse repetition frequency 150 Hz) for 5 minutes at different spatial average intensities was applied on chondrocyte cells. First, the optimum dose with significantly increased proliferation was determined to be 0.5 W/cm for 5 minutes of duration. Then, 0.5 W/cm ultrasound intensity was applied for durations of 2.5, 5, 7.5, and 10 minutes, and healing was assessed by monitoring cell migration and proliferation.

Results: At the intensity of 0.5 W/cm 48 hours after the application, a statistically significant increase in proliferation (p = .0089) was observed in chondrocyte cells compared to the control group. Proliferation was analyzed at 4, 8, 24, and 48 hours after applying 0.5 W/cm ultrasound for durations of 2.5, 5, 7.5, and 10 minutes. Statistically significant increases were observed at 4 hours (p = .009), 8 hours (p = .032), 24 hours (p = .0084), and 48 hours (p = .00098) with 10 minutes of exposure. For 7.5 min of exposure duration, significant increases were observed at 48 hours (p = .045). In migration for all parameters, no statistically significant improvement (p > .05) was observed.

Conclusion: It was shown that low intensity pulsed ultrasound induces cartilage cell proliferation; therefore, it may have a disease-modifying effect in the treatment of osteoarthritis. However, no positive effect was observed on cartilage cell migration.