Histomorphometrical analysis on the effects of two therapeutic ultrasound intensities on fracture healing in aged rats

Abstract

Introduction Experimental studies conducted in young animals show that therapeutic ultrasound (TUS) has been successfully used to shorten the healing time of bone fractures. However, they were not found in the literature, studies comparing the effect of different intensities of UST in aged animals. Objective To test the efficacy of intensity 1.0 W/cm2 and of 0.5 W/cm2 in the consolidation of experimental fracture of the tibia from aged Wistar rats. Materials and methods Three groups of 15 month old rats were submitted to a midshaft osteotomy of the tibia and then, the hind member was immobilized with a metal splint and plaster of Paris, wrapping the knee and ankle joint. One group (L), received ultrasound at 0.5 W/cm2; the other group (I), were exposed to ultrasound at 1.0 W/cm2. One control group (C), did not receive the ultrasound. Fifteen animals (five from each group) were euthanatized at the end of the first week and fifteen (five from each group) at the end of the third week. The progress of the fracture healing was performed for each group by morphometric analysis of histological sections of the fracture region. Results and conclusion The results showed that fractures treated with ultrasound at 1.0 W/cm2 healed significantly faster than did the fractures treated with ultrasound at 0.5 W/cm2 and the control.

Análise comparativa do efeito de dois protocolos de ultrassom terapêutico para regeneração de defeito ósseo crítico

“…10 A evolução apresentada nos demais pontos biológicos do GUS 5 pode ter sido motivada pelo prolongamento do estímulo no tecido ósseo, que é capaz de promover regiões de remodelação, 10 sendo considerado um tempo suficiente para promover a consolidação óssea. 18 Entretanto, alguns autores 11,22,23 afirmam que o tempo ideal para promover o estímulo osteogênico e a organização tecidual é a partir de 10 minutos, o que sugere que o ultrassom possui efeito dose-dependente quanto ao tempo de estimulação.…”

“…Os protocolos foram estabelecidos após adaptação dos utilizados por Albertin, 11 Barreto, 17 e Skau et al, 18 e realização de teste-piloto, por não se ter localizado, na literatura disponível, relato de protocolo de terapia por ultrassom terapêutico, com equipamento nacional, para regeneração de defeito ósseo Fig. 1 Etapa do procedimento cirúrgico.…”

The development of a mechanical device to stretch skeletal muscle of young and old rats

“…The device was tested to mechanically stretch the soleus muscle of young and aged rats. Thus, twelve female Wistar rats ( Rattus norvegicus albinus ) were used and divided into two groups: a young group (YG, n=6) of 3-month-old animals and an aged group (AG, n=6) of 15-month-old animals 15-17. The project followed the international ethics standard for animal experiments 18 and was approved by the Ethics Committee on Animal Use of the Pontifical Catholic University of Paraná (PUCPR) (PROTOCOL n° 732/2012).…”