Effect of low-intensity ultrasound on bone healing after unilateral femur fracture in naturally aged rats

• Grant number: 20/12613-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2021
• End date: January 31, 2022
• Field of knowledge: Health Sciences - Medicine
• Principal Investigator: Rita Cássia Menegati Dornelles
• Grantee: Michelle Vichetti Serafim
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

In women, deficiency of the reproductive hormone during menopause leads to an imbalance between resorption and bone formation, contributing to the decrease in tissue quality and favoring the incidence of osteoporosis and fractures. However, the reduction in bone quality and mass in the skeletal sites of the elderly person can result in delay or not consolidate the fracture. In addition, the occurrence of osteporotic fractures increases morbidity and mortality and the functional loss of the affected individual at any period of life, especially in old age. As a treatment, studies report that the use of low-intensity pulsed ultrasound (US) accelerates the healing of fractures in different skeletal sites, however, there is a need to elucidate whether these effects would persist in naturally aged rats during the period of estropause. Therefore, the study aims to evaluate the effect of low intensity US on unilateral femur fracture bone healing in naturally aged rats. For this, 40 Wistar rats with 24 full months will undergo a closed fracture of the right femur and after surgery the animals will be randomly distributed in the CON (untreated fracture) and US (fracture + low power ultrasound treatment) groups consisting of 20 animals each. On the third postoperative day, animals in the US group will receive low-power US treatment, 5x/week, for 2 or 4 weeks. After treatment, 10 animals from each group will be euthanized 2 or 4 weeks after the fracture to assess the effect of US on bone repair. Our hypothesis is that ultrasound accelerates the bone repair process and improves bone microarchitecture, BMD and bone strength. (AU)