Fracture Healing Enhancement With Low Intensity Pulsed Ultrasound at a Critical Application Angle

Low-magnitude high-frequency vibration enhances gene expression related to callus formation, mineralization and remodeling during osteoporotic fracture healing in rats

“…For routine monitoring of fracture healing, AP and lateral radiographs (Faxitron X‐ray system model 43855C, Wheeling, IL) were taken weekly according to our established protocol . Qualitative analysis to determine the bridging rate of each fracture was performed by two independent and blinded orthopaedic surgeons using a standard scoring system to evaluate the healing status from the x‐ray films . Quantitative analysis was also performed to determine the callus width (CW, the maximum width of callus minus the width of the cortical bone and medullary cavity at the diaphysis) and the callus area (CA, the size of radio‐opaque area of callus) by Metamorph Image Analysis System (Universal Imaging Corporation, Downingtown, PA) according to our established protocol …”

“…Six femora with the entire callus from each sample were decalcified, cut into halves along the mid‐sagittal plane and were embedded in paraffin blocks. For quantitative analysis, sections cut longitudinally (7 µm in thickness) were stained with Hematoxylin‐Eosin (H&E) . Twelve sections (six from each half) of each specimen were used for evaluation.…”

“…The region of interest (ROI) covering 3.8 mm proximal and distal to the fracture line (total 7.6 mm) was analyzed based on our previous protocol . The external callus tissues within the ROI were quantified as the total callus area (CAr) while the cartilaginous tissues area (CgAr) and the osseous tissues area (OTAr) were defined manually (Metamorph Image Analysis System, University Imaging Corporation) . The percentage of CgAr and OTAr relative to callus area were expressed as %CgAr and %OTAr, respectively.…”

“…A closed femoral fracture model was created based on previous established protocol. 15,18,20,21 Under anesthetization with katemine (20-60 mg/kg) and xylazine (2.5 mg/kg), a 1.2 mm  28 mm Kirschner wire (Sanatmetal Ltd, Hungary) was inserted into the medullary canal of the femur as an internal fixation. A 500 g steel weight was dropped with direct impact at the femur midshaft from a height of 35 cm.…”

Short-Term Effect of Low-Intensity Pulsed Ultrasound on an Ex-Vivo 3-D Tooth Culture

“…Although many experimental studies and clinical trials support that LIPUS enhances healing of fractured bone by enhancing matrix formation (Fung et al 2012;Li et al 2012), some clinical trials showed controversial results or no stimulatory effect of LIPUS in healing fractured bone (Bashardoust Tajali et al 2012). Although it has been hypothesized that LIPUS application angle is important to produce stimulatory effect on bone matrix formation at the fractured bone (Chung et al 2011), it is worth performing further research to uncover the genetic underpinning of the stimulatory or inhibitory effects of LIPUS on hard tissue matrix formation.…”