Wave propagation across a bony discontinuity simulating a healing fracture.

Stress wave propagation in a long bone with a progressively increasing defect in the bony cortex, simulating a healing fracture, was studied by recording the outputs of bonded semiconductor strain gages, proximal and distal to the defect. Statistically significant relations were found between the relative size of the discontinuity and the transmission coefficient, dispersion and transit time across the fracture. We also showed that the stress wave in a bone could be monitored from the vibration response of a traction pin, placed in a magnetic field. The results may be helpful for the development of new methods to measure the rate of fracture healing, as well as aiding our understanding of the dynamic loading of bone.