Fig. 4　 Revision surgery performed 1 month after the primary surgery.

(a, b) Radiographs at 1.5 years postoperatively. After removing the L2 pedicle screw because of major loosening, additional posterior fixation was performed using L3-4-5-S1 PS and S2 alar-iliac screws. The median hook was added to reinforce the compressive force of the L2 vertebral body in the cephalad direction, and then the lateral interbody fusion cage was inserted at the L1–2 level using the oblique lateral interbody fusion approach to gain more direct support. The local kyphotic angle at T10-L2 improved to 8°(c), finally 18º with correction angle loss of 10° at the final observation(18 months after the surgery, d).(e) Post-operative CT scan showed massive bony fusion connecting the adjacent vertebrae(arrow heads).