Ação do ultra-som de baixa intensidade sobre ossos de ratas osteopênicas

ABSTRACT

Several studies have already shown the beneficial effects of low intensity pulsed ultrasound on osteogenesis in fracture cases. However, few reports have related the ultrasound action in bone with some injury but without fracture. Thus, we induced a rat osteopenia model by ovariectomy and the proximal third of rat femur was stimulated by ultrasound (200mus burst of 1.5 MHz sine waves repeated at 1.0 kHz, 30mW/cm², SATA) for 20 min/day, during 20 days. After the treatment period, the body weight was significantly higher in the non-treated group than the treated one. No significant difference in bone mineral content was detected among the groups (p > 0.05). Also, no significant difference was noted in the mechanical properties of the femoral diaphysis. However, histologic investigations showed that the treated femur presented less microarchitectural deterioration than the non-treated group. Moreover, it was demonstrated that the treated group did show recent bone formation which was not there in the non-treated group. These results suggest that the low intensity ultrasound can interfere in a positive way on osteoporosis.