The bony endplate of a vertebra is a porous structure containing a large number of capillaries. To date, not very much is known regarding the appearance of the bony endplate microstructure, or the distribution of foramina in the bony endplate.

The purpose of this study was to provide information on this microstructure based on scanning electron microscopy (SEM) images.

The bony endplates of rats was observed by SEM scanning. The resulting SEM images were used to evaluate the structural characteristics of the bony endplates, such as the shape and the foramen distribution. Quantitative data were analyzed using SPSS software.

A bony endplate resembled a concave lens and had a unique three-dimensional structure with a large number of surface and interior foramina. The anterior side of the bony endplate had a large number of heterogeneous foramina. The majority of the foramina were seen concentrated toward the center of the bony endplate, as the density decreased further away from the center with few foramina at the margins. The posterior side of the bony endplate had numerous, larger, and more evenly distributed foramina. The integral structure resembled a sponge, and most of the foramina contained capillary structures.

The spongy structure of the bony endplate is the structural basis of nutrient transport. Depending on the location of the bony endplate, capillaries can penetrate it and contact to the cartilage endplate, thus supporting nutritional transport. The findings provide a theoretical basis for future studies on intervertebral disc degeneration.