ULTRASONIC DETERMINATION OF THE ELASTIC-MODULUS OF HUMAN CORTICAL BONE

The elastic modulus (C-ii) of the cortical bones of 19 individuals (14 femurs and 16 tibias, fixed in formalin) was determined ultrasonicall y. Elastic moduli were measured at four anatomical positions (anterior , posterior, medial and lateral) and in all three planes of orientatio n (transverse, longitudinal and radial). The mean tibial C-ii (34.11 G Pa) was greater than that obtained for femurs (32.52 GPa). The tibial longitudinal plane C-ii (34.1 GPa) was significantly greater than the femoral longitudinal plane C-ii (32.5 GPa). C-ii was significantly hig her in the tibia than the femur in both the medial and posterior anato mical positions. The anterior tibia had a significantly lower C-11 com pared to other positions. C-ii was significantly higher in the longitu dinal plane than the transverse or radial planes in both the femur and the tibia. There was no consistent difference in modulus between left and right sides. No age effects were observed. There were no signific ant differences between males and females, or between African American s and European Americans.