Sex determination using discriminant analysis of upper and lower extremity bones: New approach using the volume and surface area of digital model

This study used 110 CT images taken from donated Korean cadavers to create 3-D models of the following upper and lower limb bones: the clavicle, scapula, humerus, radius, ulna, hip bone (os coxa), femur, patella (knee cap), tibia, talus, and calcaneus. In addition, the bone volume and surface area were calculated to determine sex differences using discriminant analysis. Significant sex differences were found in all bones with respect to volume and surface area (p < 0.01). The order of volume was the same in females and males (femur > hip bone > tibia > humerus > scapula), although the order of surface area was different. The largest surface area in men was the femur and in women was the hip bone (p < 0.01). An interesting finding of this study was that the ulna is the bone with the highest accuracy for sex determination (94%). When using the surface area of multiple bones, the maximum accuracy (99.4%) was achieved. The equation was as follows: (discriminant equation of surface area; female < 0 < male) = 0.060 × clavicle + 0.020 × scapula + 0.045 × humerus + (−0.049) × radius + 0.093 × ulna + (−0.023) × hip bone + 0.091 × patella + (−0.052) × fibula + 0.043 × talus − 11.548. These results show that bone volume and surface area of extremity bones can be used for sex determination.