Evaluation of the potential clinical application of low-intensity ultrasound stimulation for preventing osteoporotic bone fracture.

This study evaluated the possible clinical application of low-intensity ultrasound (LIUS) stimulation for preventing osteoporotic bone fracture. Eight virgin 14-week-old ICR mice (weight 24.0 +/- 0.7 g) were ovariectomized to induce osteoporosis. The right hind limbs (US limbs) were stimulated with LIUS, whereas the left hind limbs (CON limbs) were not stimulated. LIUS was applied for 20 min a day, 5 days a week over a 6-week period using the following parameters: 1.5 MHz frequency, 1.0 kHz pulse repetition, 30 mW/cm(2) intensity, and 200 mus pulse length. The effective structural modulus increased significantly (p < 0.05) in the US limbs over time with the increased bone quantity, whereas that in CON limbs remained statistically constant (p > 0.05). In addition, the elastic modulus in the US limbs was generally enhanced by an increased bone quality, compared with the CON limbs. Therefore, LIUS stimulation may effectively reduce the risk of osteoporotic bone fracture by increasing the mechanical characteristics of bone via improvements in both the effective structural and elastic modulus of the osteoporotic bone. In conclusion, LIUS may potentially prove very effective clinically for preventing osteoporotic bone fractures.