Study and development of ultrasound monitoring of skeletal defects

Fatigue fractures are fine disruptions of normal bone architecture whose identification is often unreliable or difficult using x-rays (Robinson, Wilson et al.; Kundel 2004; Swischuk and Hernandez 2004). A fatigue fracture results from the application of abnormal loads to a bone with normal elastic resistance and is associated with new or different activity, and strenuous or repeated activity. The feasibility of using ultrasound to detect and monitor fatigue fractures and other structural damage in bone was established in this study. The use of Low Transient Pulse (LTP) technology to drive the ultrasound transducers proved to enhance detection resolution and quality of the ultrasound signal in comparison to the use of conventional rectangular drive pulse. Sawbone plates mimicking the properties of cortical bone and cancellous bone were used to create limb phantoms with different cut depths. A series of tests were conducted on these phantoms using Low Transient Pulse technology to demonstrate which design setup and signal parameters would maximize the sensitivity and specificity of the detection of fractures. Final experiments were carried out on sheep tibia simulating different fracture depths to prove the ability of ultrasound to detect fractures in an actual physiological environment