Development Of Controllable Stress Device And Imaging Observation Of Goat Disc Degeneration

1.Research BackgroundIn modern life,the incidence of degenerative disc disease is getting higher and higher,There are studies show that up to 80% of people may have lower back pain during their lifetime,Degenerative disc disease has long plagued people,however,the mechanism of disc degeneration is not clear.Therefore,this experiment from the cause of disc degeneration,trying to identify the specific factors of disc degeneration,which guide the clinical treatment of patients with a better solution to degenerative disc disease.From a biomechanical point of view,the spine as a supporting structure of the body provides the body with a multi-dimensional space movement.The force exerted on each functional unit of the spine is very complex,and the main current considerations are as follows: 1.Hydrostatic pressure of the disc itself 2.Axial compressive stress 3.Axial stretch stress 4.Rotational stress,etc.The experiment from the axial compressive stress to study the axial compressive stress on the degeneration of the intervertebral disc,and then guide the clinical.2.ObjectiveTo establish a controllable stress device and apply it to goats to observe the degeneration of goat intervertebral disc so as to explore the relationship between biomechanics and disc degeneration and to provide basis for the mechanism and treatment of disc degeneration.3.MethodsThe experiment is mainly divided into two parts.The first part is the use of titanium Kirschner wire to establish a controllable stress device to simplify the previous mechanical device.The experiment is simple,easy to operate and suitable for MRI(Magnetic Resonance Imaging,MRI)examination.The second part of the goat lumbar vertebrae and its parasite anatomy on the basis of the C-arm machine under the guidance of the stress device applied to the goat,goat lumbar 4/5 intervertebral disc to exert a controlled axial compression force,and thus Observation goat disc degeneration.In this experiment,a total of 16 goats in this method of modeling,the control group of 8,the experimental group of 8,the control group did not exert pressure,while the experimental group on the goat lumbar compression axial compression force of 40 N,X-ray and MRI were performed at 4 weeks postoperatively and 8 weeks postoperatively respectively.The indexes of evaluation were X-ray disc height measurement and Pfirrmann grading method as grading standards.By contrast,the degeneration of goat lumbar spine was observed.4.ResultThe experimental group through the use of titanium Kirschner wire pressure method,successfully developed a controlled stress device to achieve the pressure on the direction and size of the control.Successfully applied to goats,the operation is simple and convenient and all experimental animals survived,indicating that we designed the controllable stress device is safe and effective and highly reproducible.From 4 weeks after operation and 8 weeks after operation,we can find that the disc height and the signal intensity of disc nucleus in the experimental group were lower than those in the control group,and obviously decreased with the prolongation of time the trend of.All radiographs and MRI slices were blinded by a radiologist and the L4 / 5 disc height index(DHI)of all experimental segments was measured.All experimental goat intervertebral discs were graded and statistically analyzed according to the Pfirrmann classification.The disc height index of the compression group and the control group was measured by two independent samples t-test.The Pfirrmann grading results of the compression group and the control group were calculated by the chi-square test and P <0.05.This shows that all the experimental group goat disc degeneration have been achieved,and the degree of disc degeneration and modeling of the length of time is positively correlated.5.ConclusionAxial compression of controllable stress device is feasible to induce lumbar intervertebral disc degeneration in goats,The longer the time when the axial compression of the same controllable stress induces the goat’s intervertebral disc,the more obvious the imaging changes are.