Measurement of cortical thickness in a human cadaver femur. Conventional roentgenography versus computed tomography.

Mechanical testing of bone specimens provides information on the fundamental properties of bone and greater understanding of the mechanisms for specific injury patterns. Because the shaft of a long bone can be considered a cylinder, relatively simple models can be used to predict the response of bone to applied forces. However, the cortex thickness along the shaft must be known prior to stressing and fracturing the bone. Conventional roentgenograms and computed tomographic (CT) scans were used to measure at 300 points along the femoral shaft. Both roentgenograms and CT scans overestimated the measured cortical thicknesses by 6% (+/- 11.1%) and 13.4% (+/- 7.8%), respectively. While the roentgenographic method is more accurate, the CT method is technically easier to implement and more generally suitable for the purposes of most research.