| BackgroundIntervertebral disc herniation is a major cause of lumbocrural pain.Surgery of nucleus pulposus excision is the common treatment for disc degeneration and can achieve good clinical effect presently.Incising anulus fibrosus(AF)needed for partial excision of nucleus pulposus may cause permanent defect for AF,thus the unit of the lumbar spine biomechanics may also completely changed.So closure and repair for AF gradually brought to the attention more and more in the clinical.Part One Sheep model of intervertebral disc degenerationObjective:Sheep model of intervertebral disc degeneration was constructed after AF defected partially.Methods:Choosing 18 healthy female adult sheep,an average of 34.2 kg,which were divided into two groups randomly with each group of nine,and they were created for lumbar micro model group(experimental group,group A)and control group(control group,group B).Results:1.X ray:Intervertebral space in the models with group A narrowed 3 weeks after the operation,and gradually decline.intervertebral disc height of group did not changed in 3,6,12 weeks post operation(P>0.05),and the control group neither(P>0.05).Otherwise,there was significant difference between experimental group and control group in each point(P<0.05).2.MR imaging:T2-weighted images with nucleus pulposus in experimental group gradually reduced and also intervertebral space gradually narrowed;On contrary,T2-weighted images in intervertebral disc always show high signal with intensity in nucleus pulposus area bright and uniform,there were obvious boundary between AF and nucleus pulposus in control group with no disc degeneration.Histologic evaluation:Mansion staining showed that degenerative fiber ring showed Disordered arrangement and the nucleus pulposus with cells decreased and water cut,and the boundaries was unclear.Conclusions:Minimally invasive sheep model successfully molded with lumbar intervertebral disc degeneration from X-ray,MR imaging and Histologic evaluation.Part Two Study on cytotoxicity of fibrin glue to AFCsObjective:To evaluate the cytotoxicity of fibrin glue to AFCs.Methods:AFCs were isolated,cultured,passaged and identified,and the cytotoxicity was studied by CCK-8 method.Results:The absorbance value of the negative control group had no difference from that of the 50%and 100%fibrin glue extract groups(P>0.05),and they were all lower than that of the positive control group(P<0.05).Conclusions:the results showed that fibrin adhesive had no significant cytotoxicity to AFCs.Part Three Biomechanical strength of AF incision with application of porcine fibrin glueObjective:To evaluate the biomechanical strength of lumbar AF incision with application of porcine fibrin glue.Methods:Collecting fresh sheep lumbar spine specimens with each one intervertebral disc and two adjacent vertebral body up and down as a functional spinal unit(FSU),all were a total of 30 FSU which were divided into 3 groups,observing the repair effect with porcine fibrin glue on AF defect and biomechanical test in vitro.A.Closing the AF defect with absorbable polypropylene suture and porcine fibrin glue;B.just for AF defect with absorbable polypropylene suture;C.Cyclic loading fatigue experiment with the group chose with the better close effect after compared the group A and group B was carried out.Results:1.Biomechanical testing in vitro:its ultimate bearing capacity in the group with application of porcine fibrin glue was significantly higher than that of the group without glue(2921.3±897.2 N vs795.4±277.6N,P<0.01),after all the tests with the limit load,the suture was not damaged,but it showed that a nucleus pulposus seeping from the AF defects.Notably,AF defect closure with a porcine fibrin glue and sutureand can successfully against given circulation pressure(400 N,10000 cycles),and no leakage of nucleus pulposus.Conclusions:It showed a stronger bearing capacity for AF defect with the application of a porcine fibrin glue combined with suture have in vitro sheep experiment.Part Four A heterologous fibrin sealant for AF defect repair in a sheep model in vivoObjective:To evaluate the effect of a new heterologous fibrin sealant for intervertebral disc annulus defect repair in vivo.Methods:The procedure was same to the animal model.They were divided into four groups which were Sham operation group,blank control groupwith AF defect without closure,control group with pure suture and experimental group with porcine fibrin glue combined with suture according to the different ways for repair of AF defect and the results were evaluated according to X-ray,MR imaging and Histologic features,also bFGF and TGF-?1 were detected.Results:It had a better repair effect in experimental group with the mechanisms in down-regulating the expression of bFGF and up-regulating of TGF-?1.Conclusions:The porcine fibrin glue has good biocompatibility and better affect of closing AF defect which may reduce complications of recurrence of discherniation secondary to lumber discectomy. |
PDF Full Text Request