Fig. 4.

Mechanical testing of femurs was performed through use of a four-point bending apparatus. The outer and inner spans of the four-point bending noses are 25 mm and 6.5 mm, respectively. The radius of each bending nose is 3 mm. Each femur specimen was placed in the testing apparatus to simulate a physiological varus loading condition with the femoral head directed upward, the transepicondylar axis oriented vertically, and the crosshead oriented to apply the designated load to the medial aspect of the femur.