Anatomy of the femoral neck and head, with comparative data from Caucasians and Hong Kong Chinese.

The bony anatomy of the proximal femur consists of the femoral head, neck, and greater and lesser trochanters. In the adult the axis between the neck and the shaft averages 135 degrees. The femoral neck is anteverted from the transcondylar plane on the average 8 degrees in the adult. In measurements that we made of femora from cadavers of Caucasians, the anteversion angle averaged 7.0 degrees in males (range, --2 degrees to 35 degrees) and 10.0 degrees in females (range, -2 degrees to 25 degrees). Using similar techniques on cadavers of Hong Kong Chinese, we found that the average in males was 14.0 degrees (range, --4 degrees to 36 degrees) and 16.0 degrees in females (range, 7 degrees to 28 degrees). Normally the axis of the femoral head is parallel to the axis of the femoral neck, but specimens are found where there is retroversion of the femoral head. Sophisticated measurement techniques have confirmed the lack of roundness of the femoral head by establishing that the meridians have longer radii than the radii of the equator. Hence, the femoral head has a subtle egg or barrel shape. There are significant differences in the measurements of the head, neck, and proximal femoral shaft of average normal Caucasian and Hong Kong Chinese people.