Spondylolisthesis, acquired: What is the gold standard imaging for dynamic assessment?

Spondylolisthesis, acquired: What is the gold standard imaging for dynamic assessment?

• A. MRI of the spine
• B. CT with dynamic maneuvers
• C. Static spinal radiographs
• D. Flexion-extension radiographs

Answer: (D)

Dynamic instability in acquired spondylolisthesis is best assessed with imaging that shows how the slipped vertebra moves relative to the one below as the spine bends. Flexion-extension radiographs taken while the patient stands capture forward translation and changes in alignment when the spine is flexed and then extended. This motion directly demonstrates instability and provides a quantitative sense of slip and movement, guiding decisions about treatment such as stabilization. MRI shows nerve and soft-tissue details, and CT offers precise bony anatomy, but neither routinely measures dynamic motion like flexion-extension radiographs do. Static radiographs, by contrast, reveal slip in a single position only.

Dynamic instability in acquired spondylolisthesis is best assessed with imaging that shows how the slipped vertebra moves relative to the one below as the spine bends. Flexion-extension radiographs taken while the patient stands capture forward translation and changes in alignment when the spine is flexed and then extended. This motion directly demonstrates instability and provides a quantitative sense of slip and movement, guiding decisions about treatment such as stabilization. MRI shows nerve and soft-tissue details, and CT offers precise bony anatomy, but neither routinely measures dynamic motion like flexion-extension radiographs do. Static radiographs, by contrast, reveal slip in a single position only.