Effect of ultrasound-guided needle-knife on matrix homeostasis of rabbit cartilaginous endplate
BACKGROUND:Cartilaginous endplate stromal homeostasis is closely related to intervertebral disc degeneration.Acupotomy that releases posterior wall ligamentum flavum of the interforaminal orifice can improve the symptoms of patients with lumbar disc degeneration.Whether the mechanism of action is related to the regulation of cartilaginous endplate stromal homeostasis remains to be clarified.OBJECTIVE:To investigate the effect of ultrasound-guided needle-knife relaxation of the internal orifice of the rabbit L7/S1 intervertebral foramina on the matrix homeostasis of the rabbit cartilage endplate.METHODS:A total of 24 male New Zealand rabbits were randomly divided into a control group(n=6)and a modeling group(n=18).Lumbar disc degeneration modeling was performed by intermittent standing after transection of the supraspinous interspinous ligament for 12 weeks.After modeling,the modeling group was randomly divided into model group,needle-knife group and fake needle knife group,with 6 rabbits in each group.In the needle-knife group,the ultrasound-guided needle-knife released the ligamentum flavum posterior wall of the right intervertebral foramina,while in the fake needle-knife group,the needle-knife only reached the surface of the posterior wall ligamentum flavum of the intervertebral foramina,with a total of four interventions,each time at an interval of 1 week.No intervention was performed in the control and model groups.Thirty days after the intervention,the disc degeneration was observed by MRI.The morphology of L7/S1 intervertebral disc cartilaginous endplate,nucleus pulposus and annulus fibrosus were observed with hematoxylin-eosin and safranin O-fast green staining and was then scored.The expressions of type II collagen,proteoglycan and matrix metalloproteinase-13 in nucleus pulposus and cartilage endplate of L7/S1 intervertebral disc were detected by immunohistochemistry.RESULTS AND CONCLUSION:MRI results showed that the relative gray value of L7/S1 nucleus pulposus was significantly lower in the model group than in the control group(P<0.01),and higher in the needle-knife group than in the model group and the fake needle-knife group(P<0.05).Hematoxylin-eosin and safranin O-fast green staining showed obvious degeneration of the nucleus pulposus and annulus fibrosus,thinning of the cartilaginous endplate,and obvious calcification at the junction with bone endplate in the model group.The morphology of the cartilaginous endplate and degeneration of the nucleus pulposus were improved in the needle-knife group compared with the model group.The morphological scores of the model group,needle-knife group and fake needle-knife group were significantly higher than those of control group(P<0.01).The morphological score of the needle-knife group was significantly lower than that of the model group and fake needle-knife group(P<0.01).Immunohistochemistry results showed that compared with the control group,the expressions of type II collagen and Aggrecan in the nucleus pulposus and cartilage endplate in the model group and fake needle-knife group were significantly decreased(P<0.01),while the expression of matrix metalloproteinase-13 was significantly increased(P<0.01).Compared with the model group and fake needle-knife group,the expressions of type II collagen and Aggrecan in the nucleus pulposus and cartilage endplate were increased in the needle-knife group(P<0.05),while the expression of matrix metalloproteinase-13 was decreased significantly(P<0.01).In conclusion,the relaxation of the interforaminal orifice by needle knife can regulate the matrix homeostasis of the rabbit cartilage endplate and improve the degeneration of the intervertebral disc.
lumbar disc degenerationcartilaginous endplateneedle knifeinternal orifice of the intervertebral foraminaultrasound