Table 1.

Fusion grading system

Grade	Fusion status
I	Completely remodeled with trabeculae across the disc space
II	Graft intact with no lucent lines seen between the graft and adjacent endplates
III	Graft intact, but a radiolucent line is seen between the graft and an adjacent endplate
IV	Lucency along an entire border of the graft or around a pedicle screw or subsidence of the graft