A Research On The Effects Of Stress Intermediate Screws Method For Thoracolumbar Vertebral Endplate

Objective To explore the injured vertebra transpedicular fixation technique(6-screws construct)and different screw-path length of 6-screws construct?traditional shorter segmentpedicle instrumentation(4-screw construct)for thoracolumbar vertebral endplate stress,comparing the effect on the stability of the different ways in anterior column to provide a theoretical basis for pedicular screw fixation and screw-path length of 6-screws construct on Surgical operation.Methods Three fresh swine lumbar vertebras(contain T15-L3)were prepaired,and randomly divided into three groups.Group A 6-screw construct(Middle segment vertebral body short screw,the depth of the screw placement at the center of the vertebral bodies);Group B 6-screw construct(Middle segment vertebral body long screw,the depth of the screw placement at the anterior column of the vertebral bodies);Group C 4-screw construct(Middle segment vertebral body in screw)).Among each group of the section between thoracolumbar and vertebral endplate,Place the diaphragm resistance strain gauge,connected to the strain gauge.Then give the pressureload vertical inthe electronic universal testing machine,recorded under different load the stress value ofthe endplate.All the datas were statisted and analyzed by the SPSS 17.0 system.Use the analysis of the variance of data by completely random designed(one-wayANOVA)and LSD test.Results Randomized block design:In the trentment room,between A,B,C three groups P<0.01,suggesting thatoverall mean strain values between different groups is not all e qual.In the block room,Load value comparison between 500-4000N,P<0.01,suggesting that overall mean values of strain under different load values not all equal.By comparison,A group and B group,A group and C group,B group and C group were statistical significance between group A and group B strain value of the overall mean is unequal,the overall mean of A group?B group and C group strain values are unequal.Group B,below A and C in the two groups(P<0.01),group C endplate largest stress,there are significant statistical difference.Conclusion Compared with 4-screw construct,6-screw construct to vertebral endplate under the same load less stress,and placing longer screw deeper more will reduce the end plate load,6-screw construct and placing longer screw proved larger support of the vertebral endplate,and conclude the methods on the stability of the anterior column advantage.