Fig. 4

The same lateral plane between lying and standing positions from digital tomosynthesis in the PS loosening group. The displacement angle α (black solid line) between the PS axis (black dotted line) and the cranial endplate (white dotted line) of the same vertebra in the lying (a) and standing (b) position. The displacement angle β (black solid line) between the PS axis (black dotted line) and the caudal endplate (white dotted line) of the same vertebra in the lying (c) and standing (d) position. The displacement angle γ (black solid line) between the PS axis (black dotted line) and the posterior wall (white dotted line) of the same vertebra in the lying (e) and standing (f) position