Fig. 3

Histological assessments (Hematoxylin/Eosin stain). Histological section demonstrating early degenerative changes of in-situ immobilization intervertebral disc after 2~ 8 weeks. 1. (a~e), Intervertebral disc at low magnification (50×). The most prominent change in this specimen (b~e) is the cluster formation of the nucleus pulposus cells becomes obvious compared to control group A (a). Cells within these clusters kept their typical morphological structure with stellar-shape dnuclei and a vacuolated cytoplasm. 2. Higher magnification of IVD section shown in figure f~j (100×), the inner layer of AF appear to be progressive disorders and hyperplasia (j). Close to the NP border, the AF becomes infiltrated with chondrocyte-resembling cells. AF indicates annulus fibrosus; NP indicates nucleus pulposus; Imm indicates immobilization