Ward Triangle was put forward by Academician Zhang Yingze. Ward 'striangle: There are three different arrangements of trabecular system of femoral head and neck. One is the main pressure trabecular system, which mainly bears the pressure from the distance of femur to the weight-bearing area of femoral head; The other is the secondary pressure trabecular system, which starts below the femoral distance and ends at the greater trochanter; The other is the main tension trabecular system, which bears tension at the upper part of the femoral neck. The above three systems form a triangular fragile area in the central area where the femoral neck crosses, that is, Ward's triangle.