Ultrasonic assessment of early callus formation.

A 0.5 MHz pulse-transmission ultrasonic device is described and results obtained with an animal model presented. Two waveform components have been identified which correlate with the healing process. The "bone wave" is indicative of endosteal callus formation and the strength of cortical union. The "callus wave" is indicative of early periosteal callus formation. Recordings are presented to demonstrate the nature of the in vivo recordings, and the changes seen during the early stages of healing. In vitro recordings are presented to demonstrate that the signals are indicative of the properties of the bone and fracture, and are not soft tissue artifacts.