Physiother Theory Pract. 2022 Jul 31:1-10. doi: 10.1080/09593985.2022.2107466. Online ahead of print.
OBJECTIVE: This study aimed to evaluate the efficacy of low intensity (0.1-0.8 Watt/cm2) 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/cm2 for 5 minutes of duration. Then, 0.5 W/cm2 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/cm2 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/cm2 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.