Clinical experiences with ultrasonometric measurement of fracture healing

The use of noninvasive, acoustic methods like ultrasonometry is becoming increasingly interesting in the quantitative assessment of fracture healing. A reliable measurement technique has been described using ultrasonic transducers placed across the fracture gap. Ultrasonic image aiming is useful for accurate transducers location, on both sides of the gap. The study was designed to assess the clinical application of measurement of ultrasonic wave propagation through the fracture callus.

Contact testing was performed with a prototype ultrasonic bone tester UTTK-01 device. The measuring technique was validated experimentally on human long bones in vitro, as well on volunteers. Twenty four diaphyseal fractures of long bones were prospectively assessed. Transducers put on a fixed distance frame were properly placed with ultrasonographic focusing.

Average ultrasound propagation time was 1917 m/s. The measured values for fractures rose with time after injury. The average speed of sound measured between 10th and 21st day after fracture was 1200,85 m/s, after 7 to 8 weeks - 1559,35 m/s, after 12 weeks - 1640,64 m/s, after 16 weeks - 1735,72 m/s.

We conclude that the technique for measuring long bone ultrasound velocity with ultrasonographic centering on the fracture gap allows repetitive positioning of ultrasonic transducers for measurement. Ultrasonic measurement of bone union may support or modify clinical decision. However, further studies are required to make the ultrasonometric method easier and more user friendly for clinical studies.