First, 30 knees without hip osteoarthritis or proximal femoral surgeries were selected. Sequential hip adduction, abduction, and flexion were performed, and the femoral head was monitored fluoroscopically in the coronal plane before TKA. Significantly more movement was detected during hip adduction than during abduction and flexion. Then, postoperative femoral and tibial component alignment was retrospectively evaluated in 48 TKAs before fluoroscopic monitoring (early group) and in the next 61 TKAs with femoral registration using smaller adduction movements to avoid large femoral head movements (later group). Another 47 TKAs treated with the conventional intramedullary method for the distal femoral component and the extramedullary method for the proximal tibial component were also analyzed (IM and EM group) for historic control.