MORPHOLOGY OF THE LUMBAR VERTEBRAL END-PLATES

Study Design. The dimensions and shapes of vertebral body endplates of inferior L4, inferior and superior L5, and superior S1 were analyzed. Computed tomographic scans parallel to each endplate were used to dev elop a standardized geometric model of the boundaries of each vertebra l body. Objectives. To provide a detailed analytic and geometric model of the vertebral endplates from the inferior surface of L4 to the sup erior surface of S1. Summary of Background Data. Although measurements of the sagittal and maximum transverse diameters of the vertebral bod ies have been well documented, no study offers a complete geometric de scription of the shape of the endplates. Also, information acquired us ing the techniques of previous published reports may not provide measu rements as accurate as those of the current investigation. Methods, Tw enty-five men and 21 women were studied. Computed tomographic scans of the endplates were digitized. The data were interpolated, and multiva riate regression equations were derived to devise a standardized model . Measurements were taken, and the data were curve fitted to give best -fit equations for the standardized models. Results. The endplates res embled a cardioid at the inferior L4 level and became more elliptical toward the superior S1 level. The sagittal and transverse diameters of the endplates of inferior L4, superior and inferior L5, and superior S1 are provided and compared with those reported in previous studies. Conclusion. Although the female endplates are smaller than their male counterparts, the overall shapes are similar.