[Study of rat lumbar vertebral endplate via micro computed tomography].

OBJECTIVE:To reconstruct the 3-dimensional (3D) models of vertebral endplate and internal canal structure based upon the micro computed tomography (MicroCT) scanning data and clarify the structural characteristics and changes of bone, canals and lumbar vertebral endplates with advancing age in SD rats. METHODS:Lumbar spines from male SD rats aged 3, 9 and 16 months (n = 15 each) were subjected to MicroCT scan. Mimics software was used to reconstruct the 3D models of lumbar vertebral endplate and internal canal structure. The bone volume fraction (BV/TV) of endplate was measured by CTAn software. RESULTS:The rebuilt 3D models of vertebral endplate showed that lumbar endplate was a thin layer of bone and the canals within vertebral endplate formed a ring-shaped canal network after reconstruction. Communicating branches existed between the adjacent canals. Every ring-shaped canal connected with trunk canals lying in the ventral and dorsal portions of endplate. The BV/TV of endplate in the ventral portion was lower than that in dorsal portion (ventral side: 79.9% ± 7.3%; dorsal side: 90.6% ± 6.2%, P < 0.05) and BV/TV increased with advancing age. CONCLUSION:The canals within rat lumbar vertebral endplate are not haphazard, but regularly arrayed to form a ring-shaped network of many circular canals, communicating branches and ventral and dorsal trunk canals. This canal network provides channels for blood vessels within endplate. The ratio of older rat canals decreases in endplate.