| ObjectiveA biomechanical study of annulus sealing biomechanical effect after annulus sealing.To study the changes in the lumbar biomechanical stability of flexion-extension,lateral bending,axial rotation,pressure and fatigue experiment at different time points after the resection of various posterior structures,as well as to assess the capacity for self-healing,pig 4/5 lumbar that had undergone laminectomy or intervertebral disc extraction were used as an experimental animal model.The objective of our research is to study the effect of sealing annulus fibrosus on the biomechanical stability of lumbar spine and intradiscal pressure,and to assess the effectiveness of different operation method on sealing annulus fibrosus through quantitative cyclic fatigue loading.MethodsThe in vitro testing was performed on 30 lumbar functional spinal units(FSUs),which born the same day,age is 200-210 days,weight 110-130kg sample of the lumbar spine.We obtained spinal units from a farm.The specimens were carefully stripped of soft tissue and muscle layers,preserving all bone structures and ligaments.The treated specimens were randomly divided into groups A,B and C.In group A,laminectomy exposed the intervertebral disc but the integrity of the intervertebral disc was retained,and the exposed size and location were consistent with each group.In group B,the fibrous annulus was removed after laminectomy and the annulus sealing was put in.In group C,the fibrous annulus was taken out after laminectomy and the width of the annulus incision was about 6mm.Three-dimensional motion test was performed before each specimen was made.The three-dimensional motion test includes seven physiological conditions,including flexion-extension,lateral bending,axial rotation and pressure direction.Three-dimensional motion tests were carried out after the model was successful.The testing device includes the Instron E10000 motion measurement system and the universal material testing machine.After three-dimensional motion test is completed,each specimen is still carried out cyclic fatigue loading test in the universal material testing machine.Until the disc herniated,the specimen was damaged or the annulus sealing was damaged.ResultThere were no statistically significant differences in age and weight of pigs in the three groups(P>0.05).Mechanical loading experiment results show that the three groups of preoperative and postoperative after flexion-extension,on the left side of the lateral bending rotation,bent on the right side,left and right when axial rotation range(the range of movement,ROM)and neutral zone activity(neutral zone,NZ)values are less than the group after the surgery,the difference was statistically significant(P<0.05).However,there was no statistically significant difference between ROM and NZ values in pressure(P>0.05).There was no difference in ROM and NZ values between the three groups(P>0.05),preoperative and postoperative,the flexion-extension,lateral bending rotation,left,and right axial rotation and pressure.There was no difference between the ROM and NZ values of the two groups of symmetry directions on the left,right,left,and right axial rotation(P>0.05).The ROM and NZ values in the forward and backward symmetric directions were statistically significant(P<0.05).Flexion-extension,is comPared between group after surgery,the left elbow,lateral bending and axial rotation and right on the right side when compressed ROM and NZ value difference(P<0.05),but when left axial rotation ROM and NZ values are not statistically difference(P>0.05).In comparison between the three groups,the ROM values of the three groups were statistically significant(P<0.05),and the mean size of the three groups wasA<B<C.There was no statistically significant difference between group A and group B in the forward bending,right axis rotation and comPression direction(P>0.05),and the difference between group A and group C,group B and group C was statistically significant(P<0.05).The NZ values of the three groups were statistically significant(P<0.05),and the mean size of the three groups was A<B<C.There was no statistically significant difference between the NZ value A group and the group B in the latter extension(P>0.05).The difference between group A and group C,group B and group C was statistically significant(P<0.05),and no statistical significance was found in group B and group C in the rotation direction of the right axis(P>0.05).There were statistically significant differences between group A and group B,group A and group C(P<0.05).In the experiment of fatigue loading test,the final limit times were from group A,group B and group C(10.41 + 0.22),(9.52 + 0.32),and(7.96 + 0.44)10,000 times.The independent effect of the three groups was statistically significant(F=133.13,P=0.00),except that there was no significant difference between groups A,B and C,and the average loading frequency was A>B>C.ConclusionThe annulus fibrosus seal has a good effect on the stability of the spine.It is mainly achieved through the sealing of the annulus fibrosus,and the annulus fibrosus seal can block the protrusion of the nucleus and maintain the pressure in the intervertebral disc.To restore the integrity of the annulus fibrosus structure,maintain the stability of the spinal segment,and reduce the degeneration of the intervertebral disc.In the fatigue loading experiment,the fatigue loading effect of the specimen with the annulus fibrosus sealing was better than that of the simple disc herniation,and the annulus fibrosus sealing apparatus had a beneficial anti-fatigue effect. |
PDF Full Text Request