Hypoplasia of the Lumbar Vertebral Body Simulating Spondylolisthesis

Abstract

Fifty cases of spondylosis and spondylolisthesis were reviewed. In 9 of the 20 cases interpreted as Grade I spondylolisthesis at L5-S1, the sagittal diameter of L5 was shortened, creating a false impression of vertebral slippage. Such cases are felt to represent spondylolysis with hypoplasia of the vertebral body rather than true spondylolisthesis.

Hypoplasia of L5 and Wedging and Pseudospondylolisthesis in Patients with Spondylolysis: Study with MR Imaging

“…13 In our study, we could confirm with MR imaging the conclusions of Frank and Miller 1 that hypoplasia of L5 is a strong predictor of bilateral spondylolysis, especially in the absence of spondylolisthesis. In our series, there was no patient with hypoplasia of L5 who did not present with bilateral spondylolysis, though in the series of Frank and Miller, 1 there was 1 patient with thinning of the isthmus without a complete defect. Additional studies will have to evaluate whether hypoplasia of L5 can be seen in patients without spondylolysis, what the morphologic features of the isthmus in these patients are, and if spondylolysis eventually will develop in these patients on follow-up studies.…”

“…4 Only few articles in the anatomic or radiologic literature deal with hypoplasia of vertebral bodies, defined as a smaller anteroposterior diameter of a lower vertebra than the upper ones. 1,5 To the best of our knowledge, such hypoplasia was only described in the lumbar regions. In a series of 34 patients, Kim et al 5 found that in most cases (91.8%), hypoplasia involved 2 adjacent lumbar vertebrae, whereas hypoplasia of 1 vertebral body was very rare (8.8%).…”

“…1 The presence or absence of anterior vertebral slipping was assessed. The degree of dehydration and degeneration of the lumbar disks at L4-L5 and L5-S1 were evaluated.…”

The role of the wedge vertebra, short vertebral body, Multifidus muscle atrophy in Isthmic Spondylolisthesis; an MRI study

“…Grade V was added later, describing the ptosis of the cranial vertebra (3) . The height of the vertebral body at L5 was measured anteriorly and posteriorly, and the percentage wedging was calculated for allhypoplastic or short L5 vertebrae with the simple formula: anterior height minus posterior height, divided by anterior height, as used by Frank and Miller (5) .…”

Disproportionate Vertebral Bodies and Their Impact on Lumbar Disc Herniation

“…Vertebral hypoplasia was defined as occurring when the AP diameter of a lower vertebral body was smaller than the adjacent upper vertebral diameter [ 20 ]. The phenomenon of hypoplasia of the lumbar vertebral body simulates spondylolisthesis [ 21 ] or osteoporotic fractures [ 22 ]. They measured the AP diameter of the middle of the vertebral body on sagittal MR images and reported the differences in the ratio (percentage) between two consecutive vertebral bodies.…”