437570.fig.001a
(a)
437570.fig.001b
(b)
Figure 1: Anteroposterior radiographs. (a) A 61-year-old female who underwent Dynesys stabilization at 12-month postoperation. The double halo sign indicated loosening of the left L3 pedicle screw. (b) A 75-year-old male who underwent Dynesys stabilization, at 2-year postoperation. The double halo sign indicated screw loosening of the left L5 and the halo sign indicated screw loosening of the left L3 screws. Arrowhead, double halo sign; arrow, halo sign.