The micromechanical environment of intervertebral disc cells: Effect of matrix anisotropy and cell geometry predicted by a linear model

Cells of the intervertebral disc exhibit spatial variations in phenotype an d morphology that may be related to differences bl their local mechanical e nvironments. In this study, the stresses, strains, and dilatations in and a round cells of the intervertebral disc were studied with nit analytical mod el of the cell as a mechanical inclusion embedded in a transversely isotrop ic matrix. In response to tensile lending of the matrix, the local mechanic al environment of the cell differed among the anatomic regions of the disc and was strongly influenced by changes in both matrix anisotropy and parame ters of cell geometry. The results of this study suggest that the local cel lular mechanical environment may play a role in determining both cell morph ology in situ and the inhomogeneous response to mechanical loading observed in cells of the disc.