Influence of mononuclear cell therapy on disc degeneration in rabbits☆

OBJECTIVE The objective of this research was to evaluate the influence of autologous mononuclear stem cells injections on histological changes of collagen in the fibrous annulus of the intervertebral disk after experimental injury. METHODS 32 New Zealand rabbits were submitted to intervertebral disk puncture, followed by intradiscal injection of mononuclear cells from the iliac crest versus saline injection in the following time periods: two months after the injury (SC2M and SS2M), two weeks (SC2W and SS2W) immediately after injury (SCCP and SSCP), and without inducing degeneration (SCSP and SSSP). Two months after cell therapy, the animals were euthanized and collagen changes in the intervertebral discs were histologically evaluated. RESULTS There were significant differences in ELAF between SS2W and SS2S groups (p = 0.018). This difference was due to an increase in type I collagen in SS2W group (56.7%) compared to SC2S (13.28%). CONCLUSION Treatment with mononuclear mesenchymal stem cells reduced changes in the type I and III collagen distribution in rabbits AF degenerated discs up to two weeks after the induction of degeneration.