Histological changes caused by continuous ultrasonic waves of 01 MHz on the epiphyseal disk of murine tibia

Abstract

AIMS: To evaluate the histological changes in the epiphyseal disk of the tibia in growing mice during exposure to ultrasonic waves of 1MHz frequency. METHODS: Experimental study of quantitative and randomized nature. For this purpose, 16 Swiss albino mice of the Webster strain, during growth, aged 3 weeks and weighing 10-15 g were randomly divided into two groups of eight animals each and exposed to ultrasonic waves in the right tibia. Groups D1 (exposed to a dose of 0.1 W/cm2) and D2 (exposed dose of 0.5 W/cm2) were assigned. The control group, designated C, was represented by 16 samples relating to the contralateral side of each animal of groups D1 and D2. Procedures occurred in an application/day, totaling 10 applications without interruption. The samples were analyzed histological by hematoxylin-eosin staining techniques, Alcian blue and Von Kossa stains, in order to measure the area of the head versus the tibia epiphysial disc, beyond the thickness of the proliferative and hypertrophic zones. For statistical analysis we used the Friedman test with Bonferroni correction. RESULTS: The bone tissue was influenced by ultrasonic waves, as well as the epiphyseal plate, where the group had the largest parameter of the total area larger than the other disc. The calcified zone was not influenced by the ultrasonic waves, but the proliferative zone was sensitive to this therapy, especially at the lowest dose. No pathological changes were found in the treated and control groups. CONCLUSIONS: With the parameters used in this study positive action of ultrasound was observed in the cartilage and bone tissue formation, not being possible to determine what was the intensity level of the application of ultrasound statistically more significant.