Experimental Study On Rehydration Of Goit IDD Induced By Controllable Axial Tension Stress

Objective: To explore the Imaging and Pathological characteristics of goat degenerative intervertebral disc under axial tension stress over time,so as to provide a more scientific,reasonable,effective and accurate objective theoretical basis for traction treatment of IDD low back pain.Methods: The goats with intervertebral disc degeneration induced by axial compression(12 weeks)were randomly divided into 2 groups(ABC group as control group,CDF group as experimental group,4 goats in each group).The ABC group was relieved of axial compression stress(4 weeks,6 weeks,8weeks).In CDF group,an elastic stress device was used to apply an axial tension stress of 40 N to the degenerated intervertebral discs of goats(4 weeks,6 weeks,8 weeks).The height and degeneration of intervertebral discs were observed by X-ray DHI and Pfirrmann grading(Magnetic Resonance Imaging),and the changes of HE staining of Pathological sections and Ⅰ and type Ⅰ collagen immunohistochemical staining in intervertebral disc histology were observed under microscope.Results: Control group(ABC): with the extension of time,DHI of intervertebral disc except AB group(P=0.4308)had statistical significance,and Pfirrmann grade had no statistical significance(P > 0.05).He staining showed loose arrangement of fibrous annulus,chondrocyte and few nucleus pulposus cells.Immunohistochemical staining of the nucleus pulposus showed yellow collagen type Ⅰ staining(positive)and light yellow collagen type Ⅱ staining(negative).In the experimental group(DEF),DHI height increased gradually with the prolonging of time,with statistical significance(P < 0.05),Pfirrmann grading changed from high to low with the prolonging of time(Ⅴ→Ⅲ→Ⅳ),HE staining show that the annulus fibrosus was semi-annular,with many fibroblasts and nucleus pulposus cells,Immunohistochemical staining of nucleus pulpoporei showed yellow → light yellow →yellow for type Ⅰ collagen staining,and light yellow → yellow → light yellow for type Ⅱ collagen staining,indicating that quantitative axial tension stress could induce rehydration of goat IDD,which was most obvious at 6 weeks.However,too long traction time(8 weeks)would lead to degeneration of rehydration intervertebral discs.Conclusions: Quantified tension stress can induce rehydration of IDD in goats,but the duration of traction must be moderate,as beyond a certain range will lead to disc degeneration.