Measurement of the velocity of ultrasound in the human femur in vivo

Abstract

A pulse-echo technique for measuring the velocity of ultrasound in the cortex of the femur in vivo is presented. Average result for 27 asymptomatic volunteers was 3250 .+-. 190 m/s. The results showed no significant differences between proximal and distal femoral sites, right and left femora, males and females. There was also no significant difference between the velocity of sound in the femur and in the radius in normal volunteers. Reproducibility of the time of flight measurement for 3 volunteers was about 2%, and the total uncertainty of the femoral velocity of ultrasound measurement was 4% for proximal sites and 7% for distal sites. As the femur is a load-bearing bone, the site of frequent fracture in the elderly and in the osteoporotic, the measurement of the velocity of sound at this new site may of great value in investigating these conditions and may be ultimately be helpful in assessing quality of the femoral cortex in patients undergoing total hip or knee replacement.