Influence of Location, Fluid Flow Direction, and Tissue Maturity on the Macroscopic Permeability of Vertebral End Plates

Abstract

The results from this animal study showed that the central zone of the vertebral endplate was more permeable than the periphery and the flow-out permeability was up to 35% greater than the flow-in permeability. Increase of permeability with decrease of cartilage thickness was noticed within the same age group. We also found a statistically significant decrease of the macroscopic permeability correlated with the tissue maturity.

Evaluation of intervertebral disc cartilaginous endplate structure using magnetic resonance imaging

“…It functions both as a mechanical barrier between the pressurized NP and the vertebral bone, as well as a gateway for nutrient transport into the disc from adjacent blood vessels [9][10][11][12]. With intervertebral disc degeneration, the CEP becomes sclerotic, loses vascular contact, and exhibits decreased permeability [13][14][15][16][17][18][19]. This process is considered to contribute to disc degeneration by reducing the diffusion of nutrients to the cells of the NP [6,[20][21][22].…”

Correlations between effective permeability and marrow contact channels surface of vertebral endplates

“…7,16,17 This nutrition route is precarious 17,18 and is compromised in case of VEP disorders. 8,19 Because they constrained the flow through the endplate, marrow contact channels are of prime influence on the energy loss by the fluid. In our study, we investigated the region of interest corresponding with the contact surface between the vascular network and the CEP.…”

“…The specimens were carefully inserted into silicone tubes and then frozen for storage within 6 h at À238C in Ringer's solution added with 10% cryoprotectant dimethyl sulfoxide (DMSO) and 100 IU/ml heparin. 8 Fracture of some specimens occurred during sampling and made them unsuitable either for permeability measurement or the micro-CT study. The number of available specimens for the entire study is reported in Table 1.…”

“…4,6 There is a link between permeability and vascular supply as permeability is greater in the center of the VEP [6][7][8] where vascular network is the more dense.…”

“…2,3 Vascular buds are in direct contact with the CEP through marrow contact channels crossing the calcified layer of the VEP 4,5 which represents a barrier to solute transport. 4,6 There is a link between permeability and vascular supply as permeability is greater in the center of the VEP [6][7][8] where vascular network is the more dense. 3,4,6 Oki et al 9 have shown that the density of the vascular buds does not vary significantly between the region of the CEP facing the annulus and the one facing the nucleus pulposus.…”