DLIF they bolt your vertebrae together after putting a spacer between the vertebrae. XLIF they dig out your spine disc and hammer a plastic spacer in, and close ya up. Nothing to hold you together. NO FIXATION! There were pictures of the Coroent XL plastic spacer falling out of the disc space via Google images....but they've since been scrubbed from the search engine...ha ha ha ha! $$$$$XLIF$$$$$===Fast money.
