Fig. 1

Schematic diagram showing the measurement of biomechanical parameters determined by postoperative radiographs after total hip arthroplasty. 1, horizontal hip center of rotation; 2, vertical hip center of rotation; 3, vertical femoral offset; 4, horizontal femoral offset; 5, abductor lever arm; 6, limb length. (A), vertical teardrop line; (B), horizontal tear drop line; (C), midline lesser trochanter; D, femoral shaft axis; E, tangential line to the greater trochanter; F, bi-ischial line; G, lower line of lesser trochanter