Fig. 1

Postoperative radiograph after THA with impacting bone grafting combined with a cementless cup. A, horizontal teardrop line; B, vertical teardrop line; C, midline lesser trochanter; D, a line along the lateral surface of the acetabular component; F, femoral shaft line. 1, horizontal hip center of rotation; 2, vertical hip center of rotation; 3, horizontal femoral offset; 4 vertical femoral offset; α, the angle between a line drawn between line A and line D