Fig. 1.

Digital radiologic images on which total inter-vertebral height (TIH) of the two fused vertebral bodies. The distance between the mid-point of upper end plate of cranial vertebral body and the mid-point of lower end plate of caudal vertebral body was measured with in-built software (Marosis 5.0 PACS viewer, Marotech, Korea). TIH are measured on the postoperative lateral plain radiograph (A), postoperative mid-sagittal 2D computed tomography (B), preoperative mid-sagittal T1-weighted magnetic resonance image (C).