TY - EJOU
AU - Wu, Yongren
AU - Cisewski, Sarah
AU - Sachs, Barton L.
AU - Yao, Hai
TI - Effect of Cartilage Endplate on Cell Based Disc Regeneration: A Finite Element Analysis
T2 - Molecular \& Cellular Biomechanics
PY - 2013
VL - 10
IS - 2
SN - 1556-5300
AB - This study examines the effects of cartilage endplate (CEP) calcification
and the injection of intervertebral disc (IVD) cells on the nutrition distributions
inside the human IVD under physiological loading conditions using multiphasic
finite element modeling. The human disc was modeled as an inhomogeneous mixture
consisting of a charged elastic solid, water, ions (Na+ and Cl−), and nutrient solute(oxygen,glucose and lactate) phases. The effect of the endplate calcification was simulated by a reduction of the tissue porosity (i.e., water volume faction) from 0.60 to 0.48. The effect of cell injection was simulated by increasing the cell density in the nucleus pulposus (NP) region by 50%, 100%, and 150%. Strain-dependent transport properties(e.g., hydraulic permeability and solute diffusivities) were considered to couple the solute transport and the mechanical loading. The simulation results showed that nutrient solute distribution inside the discis maintained at a stable state during the day and night. The physiological diurnal cyclic loading does not change the nutrient environment in the human IVD. The cartilage endplate plays a significant role in the nutrient supply to human IVD. Calcification of the cartilage endplate significantly reduces the nutrient levels in human IVD. Therefore, in cell based therapy for IVD regeneration, theincreased nutrient demand as a result of cell injection needs to be addressed. Excessive numbers of injected cells may cause further deterioration of the nutrient environment in the degenerated disc. This study is important for understanding the pathology of IVD degeneration and providing new insights into cell based therapies for low back pain.
KW - Intervertebral disc (IVD)
KW - Mixture theory
KW - Finite element method
KW - Cartilage endplate
KW - Nutrient supply
KW - Tissue regeneration
KW - Disc degeneration
KW - Low back pain
DO - 10.3970/mcb.2013.010.159