There are multiple pain generators of the lumbar spine and detecting degenerative changes and their extent are important in clinical management.
The normal lumbar spine has a lordotic curvature.
The anterior and posterior cortices of the vertebral bodies should align with the adjacent bodies. Anterior alignment of a body relative to the body caudal to it is anterolisthesis. In contrast, posterior alignment of the body relative to the body caudal to it is retrolisthesis. Flexion and extension radiographs can depict abnormal motion between vertebral bodies.
Disc degeneration is detected radiographically by disc height loss and endplate sclerosis and osteophyte formation.
FINDINGS: Straightening of normal lumbar lordosis. Minimal retrolisthesis of L1 on L2, L2 on L3, and L3 on L4. Vertebral body heights are maintained. Multilevel degenerative changes, characterized mainly by disc height loss, endplate osteophytes, and facet arthropathy, most pronounced at L1-L2 and L4-L5.
Degenerated facet joints can be detected by subchondral sclerosis, osteophyte formation, and joint space narrowing.
Radiographically normal facets depicted on the left and facet arthropathy depicted on the right.
Winking owl sign- apparent absence of pedicle cortex as seen on AP projection with intact contralateral pedicle. Often seen in the setting of lytic bone lesions.