Rotation center measurements and femoral measurements. The interteardrop line was defined as the horizontal reference line. RFNL was the perpendicular distance of a line passing through the medial cortex of femoral osteotomy to the corresponding tip of the lesser trochanter. LLD was the difference in perpendicular distance of a line passing through the RC to the corresponding tip of the lesser trochanter. Offset was the perpendicular distance passing through the RC to the longitudinal axis of the femur.