What findings on a lumbar radiograph might suggest spondylolisthesis?

What findings on a lumbar radiograph might suggest spondylolisthesis?

• A. Posterior disc space narrowing.
• B. Vertical alignment mismatch.
• C. Anterior displacement of a vertebral body relative to the one below on a lateral view; possible pars defect.
• D. Spinous process elongation.

Answer: (C)

Forward slippage of a vertebral body relative to the one below on a lateral lumbar radiograph is the hallmark of spondylolisthesis. This anterior displacement may be partial or complete and is often linked to a pars interarticularis defect (pars defect) that destabilizes the lumbosacral junction, allowing the vertebra to slide forward. In practice, you can quantify the slip with percent slip or Meyerding grade to describe how far it has advanced. The other options don’t fit this scenario: posterior disc space narrowing points to degenerative disc disease rather than slippage; a vertical alignment mismatch is too nonspecific and can occur with scoliosis or other misalignments; spinous process elongation is not a typical sign of spondylolisthesis.

Forward slippage of a vertebral body relative to the one below on a lateral lumbar radiograph is the hallmark of spondylolisthesis. This anterior displacement may be partial or complete and is often linked to a pars interarticularis defect (pars defect) that destabilizes the lumbosacral junction, allowing the vertebra to slide forward. In practice, you can quantify the slip with percent slip or Meyerding grade to describe how far it has advanced.

The other options don’t fit this scenario: posterior disc space narrowing points to degenerative disc disease rather than slippage; a vertical alignment mismatch is too nonspecific and can occur with scoliosis or other misalignments; spinous process elongation is not a typical sign of spondylolisthesis.