Pseudolisthesis Secondary to Small L5 Vertebra

"nIntroduction: The aim of this retrospective study was to differentiate between small fifth lumbar (L5) vertebral body diameter as normal variant with spondylolisthesis. "nMaterials and Methods: Three radiologists reviewed 2000 lumbosacral MRIs of different patients who were referred for any problems to a imaging center during 3 months. The patients with a previous history of lumbosacral surgery and congenital lumbar anomalies were excluded from the study. "nResults: In these 2000 lumbosacral MRIs, 87 cases showed anterior stepping of the posterior wall of L5 in comparison with posterior wall of L4 (These cases can be reported as spondylolisthesis or pseudospondylolisthesis in MRI reports ). 46 cases (2.3%) show true spondylolisthesis and 41 cases (2.05 %) show small anteroposterior diameter of the body of L5 in comparison with L4. "nConclusion: Small AP diameter of L5 is a normal variant in about 2% of lumbosacral MRIs, which can mimic spondylolisthesis.