Distinguishing Race Based on the Intercondylar Shelf Angle in the Distal Femur

 

Procedure:

(1) The distal femur is placed on a support (foam, box, towel).

(2) An X-ray is taken through the coronal plane (on its side with film below, or posterior aspect down with film vertical at 90°).

(3) The angle between Blumensaat's line and a line running along the posterior cortex of the femoral shaft is measured.

Angle	Interpretation
<= 138°	Black
139 – 141°	probably Black
142 - 143°	uncertain
144 – 146°	probably White
>= 147°	White

from Figure 6, page 780.