Retrolisthesis is defined as which movement?

Retrolisthesis is defined as which movement?

• A. Backward slippage of a vertebra relative to the one above it
• B. Forward slippage
• C. No movement
• D. Lateral translation

Answer: (A)

The movement being tested is the backward, or posterior, slip of a vertebral body relative to the vertebra above it. That backward displacement is what retrolisthesis describes, contrasting with forward slip (spondylolisthesis) where the vertebra slides forward relative to the one below. From a clinical perspective, a retrolisthesis means the vertebra has moved back toward the back of the spine, which can affect the posterior elements and potentially narrow the spinal canal or alter nerve root spacing depending on the level and degree of slip. Why the other ideas don’t fit: a forward slip describes spondylolisthesis, not retrolisthesis; no movement would imply normal alignment rather than a slip; lateral translation refers to a side-to-side shift, which is a different pattern of vertebral movement altogether.

The movement being tested is the backward, or posterior, slip of a vertebral body relative to the vertebra above it. That backward displacement is what retrolisthesis describes, contrasting with forward slip (spondylolisthesis) where the vertebra slides forward relative to the one below. From a clinical perspective, a retrolisthesis means the vertebra has moved back toward the back of the spine, which can affect the posterior elements and potentially narrow the spinal canal or alter nerve root spacing depending on the level and degree of slip.

Why the other ideas don’t fit: a forward slip describes spondylolisthesis, not retrolisthesis; no movement would imply normal alignment rather than a slip; lateral translation refers to a side-to-side shift, which is a different pattern of vertebral movement altogether.