Evaluation of Lumbar Vertebral Body and Disc: A Stereological Morphometric Study

Abstract

Anterior access to the L1-L5 vertebrae and disc spaces can be technically challenging, frequently requiring the use of an approach to a surgeon for an adequate exposure. The technique is used for lesion excision, corpectomy, vertebral body reconstruction with cages, realignment, and/or plating or screwing. For a successful anterior approach and a suitable instrumental design via screw, adequate morphometric knowledge about body of lumbar vertebrae and disc spaces and standardized volumetric data are also required for neurosurgeons. We aimed morphometric and volumetric evaluation of lumbar bodies and discs to contribute to a safe anterior approach during surgery. We evaluated vertebral body and disc morphometry using stereology in right-handed 25 adult subjects on MRI in the same population with no history of vertebral fractures and degenerative spinal disease. The shape, defining concavity index and volumetric measurements of the body L1-L5 vertebrae, morphometric parameters such as length, height, width of the vertebral body were measured. Also morphometric and volumetric analysis of discs between L1 and L5 were evaluated selected axial and sagittal slices. As expected, the average dimensions of male vertebrae are greater than those of females, but most of them do not differ statistically. Only three dimensions, the mean difference between anterior and central heights of L3, L4 and L5 showed statistically significant difference, indicating smaller central height in both males and females. The transverse and anterior-posterior diameters of the vertebral body, intervertebral disc height and volume displayed no sexual dimorphism (p>0.05). But, the intervertebral disc height and volume increased from L1 to L5 (p<0.01). Concavity indexes for all lumbar vertebrae for both sexes did not differ statistically. The method is important to estimate applying implant size and amount in decompression operations for neurosurgeons.