Fig. 1

a This degenerative lumbar kyphoscoliosis case had fused vertebrae at L3–4 (white arrowhead). Anterior vertebral autofusion was found in the concave side of the lumbar curve. b In the same case, the remnant disc was found on T2 weighted image of magnetic resonance image at the intervertebral space of L3/4 level (black arrowhead). c A Cobb elevator with 18 mm width was inserted into the disc space from the non-fused side and penetrated to the contralateral side under a fluoroscope. d Subsequently, a 6 mm thick Paddle Sizer® was inserted to completely accomplish the release between the fused vertebrae