Question: what is a grade 1 retrolisthesis of l5 on s1?
Answer: Grade 1 retrolistheses of C3 on C4 and C4 on C5. Specialty. Orthpedic. A retrolisthesis is a posterior displacement of one vertebral body with respect to the subjacent vertebra to a degree less than a luxation (dislocation). Retrolistheses are most easily diagnosed on lateral x-ray views of the spine.