Effect of medullary cavity on the two wave phenomenon in the distal part of long bone

In the early stage of osteoporosis, the medullary cavity (a hole in the cancellous bone) becomes larger in addition to the decrease of bone volume. The effects of such structural changes seem important to understand the process of osteoporosis. In this study, we experimentally studied effects of medullary cavity on the two wave phenomenon. The slow wave amplitudes decreased with the decrease of the medullary cavity area in the measurement area where cancellous bone exist enough.