Mechanical monitoring of fracture healing using ultrasound imaging.
Ultrasound scanning is based on biologic noninvasive use of high-frequency sonic vibration ultrasounds to obtain images of diagnostic relevance in vivo. Ultrasound scanning was used as an additional parameter in evaluation of healing of long bone fractures in patients treated by external fixation devices. Ultrasound image morphology is directly correlated to consolidation of fracture site and displays characteristic cuspid-like shapes in relationship to callus remodeling in response to axial forces. The intensity of reflected echo and the visualization of the longitudinal artifacts structure are significantly related to the calcification process of the periosteal apposition in relationship to healing time. Strain-recorded maximal values variations are synchronous with the variations of reflected echo demonstrating a correlation between the ultrasound image and mechanical status of external callus. In the current state-of-the-art, no quantitative evaluation of mechanical status of fracture site is possible by ultrasound technique alone.