A rat model of sciatica induced by autologous nucleus pulposus implant at outlet of lumbar intervertebral foramen

Objective To establish a new rat model for sciatica induced by autologous nucleus pulposus implant at outlet of lumbar intervertebral foramen. Methods A total of 54 male SD rats were randomly divided into a model group,a sham operation group and a blank group,18 rats in each one. 6 rats were selected from each group and observed on general behaviors and measured with 50% Paw Withdrawal Threshold( PWT) 1 day before surgery and 1,3,5,7,10 and 14 days after the surgery. Another 6 rats from each group were selected and tested with the expression of NOS and COX-2 in L5 dorsal root ganglion( DRG) after 3 days and 7 days of the surgery. Results No obvious motor dysfunction was seen in all rats. 50% PWT in model group after surgery was significantly lower than that before surgery and also significantly lower than that in the blank group and sham operation group( P 0. 01). The positive cells of NOS and COX-2 in L5 DRG in model group were significantly increased than that in the blank and sham operation group respectively after 3 days and 7 days of the surgery( P 0. 01). Conclusion This new rat model of sciatica induced by autologous nucleus pulposus implant at outlet of lumbar intervertebral foramen is convenient with less damage on joint structure,which can provide positive and stable pain. It could offer experiment basis for mechanism research regarding conservative therapies on radical irritation,especially for spinal manipulation.