Bromechanical Experiments Of The Injured Vertebral Monosagmerit With Across The Injured Vertebral Short-segmental Fixation For Denis B Thoracolumbar Burst Fracture

Objective: Thoracolumbar burst fracture of spine fracture iscommon in clinical type. Surgical treatment is prefered choice， butfor the choice of operation are controversial. Through this study forthoracolumbar burst fracture animal models in vitro biomechanicalexperiments. Measurement of single segment fixation group withshort-segmental fixation group in automatic control electronicuniversal testing machine to simulate proneness， stretch loadstress after surgery and adjacent segment under load and strainchange， Compare the biomechanical characteristics of the twokinds of fixed way. From the perspective of biomechanicsevaluation two fixed way influence on the stability ofthoracolumbar， provide theoretical basis for clinical applicationand experimental instruction.Methods:Select8mavericks spine specimens with T11to L3.The specimen after embedding， fixed in the automatic controlelectronic universal testing machine，through dynamic resistancestrain gauge to measure the strain value of the measuring point.Then specimens made by the pre-compression or after injury of theimpact method L1vertebral burst fracture model， the damage onthe end plate， keep complete endplate. Eight specimens wererandomly divided into the injured vertebra monosegmental fixationgroup， across the injured vertebral short-segmental fixation group.And the same way to measure the strain value of measuring points. Analysis of the operation section and adjacent segment of load andstrain change. Using SPSS16.0software package (SPSS，Chicago， IL， USA) for data analysis， the comparison ofdifference between groups of data Scheffe method is used tocompare， P <0.05for the difference has a significant meaning.Results：1. Two kinds of fixed way all can live with a fixed intensity， enoughto maintain the stability of the vertebral bodies.2. With short-segmental fixation compared with monosegmentalfixation nail bar under the stress of smaller， can better restorevertebral body height，and lower the incidence of screw rod fatiguefracture.3. The single section with a short segment group there are certainstress shelter， which fixed way but this has not been able tocompare the stress shelter effect more apparent.Conclusion:The monosegmental fixation and short-segmental fixation canobtain good real-time stability， for a particular Denis type B burstfracture， monosegmental fixation is a good choice.