Figure 1.

(A) Segmental vertebral body height: The distance between the midpoint of the cranial vertebra upper endplate and the midpoint of the caudal vertebra lower endplate at the fusion level. (B) “The Graft/Endplate ratio” is defined as graft length (G) divided by endplate length (E) to determine the relative size of the graft to the endplate. E: endplate length: the length of the line passing through the center of the graft from the posterior margin of the plate to the posterior disc margin at the treated level. G: graft length.