| Objective:Reproduce the model of lumbar intervertebral disc degeneration in rats by Puncturing fiber ring.Observe whether the model is a lot to crack the morphology and biomechanical changes of multifidus.Explain the mechanism of Passive lumbar back extension in the treatment of low back pain.Provide new ideas and experimental support for clinical conservative treatment of discogenic low back pain.Methods: eight-week-old male Wistar rats(200 ± 20g)were randomly divided into sham group,the intervention group,model control group,each 15.Model control group and the intervention group rats were intraperitoneally surgery,then use 21 G needle puncture rat L4 / 5 and L5 / 6 intervertebral disc,while the aham group only surgery but not puncture the fiber ring.Begin to implement passive lumbar extensor intervention after the gas anesthesia with a self-made exerciser two weeks after modeling.Gas anesthesia model control group and the sham group without waist dorsiflexion intervention,a total of 30 days time.Study all behavior change of rats.Conduct all rats a behavioral test at three time points of before modeling,modeling after two weeks and after the intervention with infrared animal behavior tester.Record the total time in rats upright than 12 cm height within 5min and then analysis.It reflects the degree of low back pain of rats of weight-bearing.After the end of the intervention,all rats were sacrificed and drawn rats multifidus muscle,L4 / 5 and L5 / 6 intervertebral disc,take half of the multifidus muscle tissue biomechanical analysis,testing their abdominal muscle cross-sectional area,the maximum tensile strength data and then analyze them.Dye the other half multifidus and intervertebral disc and analyze the morphological changes.Results: 1.Behavioral studies:Two weeks later modeling,model group and intervention group were standing time is shorter than before modeling(P<0.05),Prompted above two groups of rats modeling occurred waist weight-bearing pain after modeling.Standing time count of the intervention group were increased compared with after modeling after the intervention(P <0.05).Meant that back pain symptoms eased in rats after passive dorsiflexion intervention.In the model group,no significant change in the standing time of the model group when compared with that of the model(P>0.05).Meant waist rats in this group had no significant weight-bearing pain relief,but the intervention group and model group rats`s standing time were lower than which before modeling,which prompting two groups of rats`s waist pain did not return to normal levels.2.multifidus biomechanical studies:Tensile tests on rats multifidus found that difference of maximum tension of multifidus among three groups was statistically significant(P<0.05).SNK-q test showed that the maximum tension differences among the three groups were statistically significant which meant multifidus muscle tensile capacity decreased after intervertebral discs degeneration in rats.By the intervention of passive dorsiflexion,their tensile capacity had improved but had not been restored to the level of sham group.Displacement difference among three groups of rats of multifidus muscle when pulled off had no statistical significance(P>0.05).3.multifidus morphological studies:Comparison of the sham group,model control and intervention groups showed that multifidus cross sectional area of a statistically significant difference(P<0.05).SNK-q test showed that the differences among the three groups were statistically significant which showed that rats multifidus were shrinking after modeling.After the intervention of passive dorsiflexion multifidus muscle atrophy situation has improved.Sham group multifidus muscle fibers arranged orderly and Distribution of muscle fibers closely distributed.Muscle cell nucleus intact,round or oval,which distributed in the muscle fibers of the longitudinal axis or the edge position in the center of the muscle fibers.Model groups`s multifidus muscle degenerated significantly that the stripes of muscle became blurred or partially disappear and muscle cell nucleus scattered distribution.Intervention group multifidus muscle fibers mild degenerated.Stripes of muscle fibers became a little unclear.Muscle fiber separation or fusion phenomenon occasionally appeared.4.The disc morphological studies:Annulus shape sham group of very complete,the junction of the annulus and nucleus pulposus is clearly visible,the disc nucleus pulposus cells are concentrated in the central region.Morphological changes of intervertebral disc tissue of rats in model group were obviously,annulus arrangement position change,the level of the distribution unclear.Nucleus pulposus sparsely distributed in the central region.There were slight histological changes and Slightly fibrous ring rupture in the intervention group.Morphological changes were lighter than the model group.Conclusion:1.By way of puncture intervertebral disc can lead to rat intervertebral disc degeneration Which led to lumbar disc herniation.Model established by the present method was stable and reliable.Disc degeneration model reproduced by way of puncture intervertebral disc annulus could lead to multifidus muscle atrophy.2.A certain level of passive dorsiflexion waist exercise can relieve lower back pain model rats,improve atrophy of disc multifidus muscle and increase muscle multifidus`s tensile capacity... |
PDF Full Text Request