Patients operated with a total hip replacement due to unilateral osteoarthritis of the hip. Radiographic measurements of the postoperative radiographs.

LLD on radiographs was defined as the difference in perpendicular distance in millimetres between a line passing through the lower edge of the teardrop points to the corresponding tip of the lesser trochanter. The interobserver reliability was assessed from the measurements made by three independent observers.

Measurement of FO using the Sundsvall method was carried out on the AP view of the pelvis as the horizontal distance (parallel to Hilgenreiners line) between the femoral axis (a line drawn through the center of the femoral shaft) and the mid line of the pelvis, at the height of the lateral tip of the greater trochanter. The measurement was performed bilaterally to compare the femoral offset on the operated side to the non-operated hip. The interobserver reliability was assessed from the measurements made by three independent observers.

Measurement of FO with the standard method was carried out on AP view as the addition of the distance between the longitudinal axis of the femur to center of femoral head and the distance from the center of the femoral head to a perpendicular line passing through the medial edge of the ipsilateral teardrop point of the pelvis. The measurement was repeated bilaterally to compare the FO of the operated side to non-operated hip. The interobserver reliability was assessed from the measurements made by three independent observers.

Cup inclination was measured on AP view as angle in degrees, between a line drawn along the angle of rim of the cup and trans-ischial line (a line drawn between the most inferior point of the ischial tuberosities). The interobserver reliability was assessed from the measurements made by three independent observers.