Alignment of the operative and non-operative levels should both be assessed.
Familiarity with surgical intervention and hardware will aid in the assessment of normal post-operative appearance.
Segments adjacent to surgical change should be assessed for early degenerative change.
On follow up imaging, look specifically for change in hardware alignment and/or fractured components.
Look for increased lucency about hardware, which may suggest motion and/or infection in the appropriate clinical setting.
Imaging of Current Spinal Hardware: Lumbar Spine. Alice S. Ha and Jonelle M. Petscavage-Thomas. American Journal of Roentgenology 2014 203:3, 573-581