1. Anterior tilt group (preoperative standing APP > 10°): Reference, standing APP −10° | 9 hips |
2. Intermediate group (−10° < preoperative standing APP ≤ 10°): Reference, supine APP | 45 hips |
3. Posterior tilt group (preoperative standing APP ≤ −10°) | 21 hips |
LLA > 30°: 11 hips; reference, supine APP | |
LLA ≤ 30°: 10 hips; reference, the midpoint between the supine and standing APPs |