Study Of Posterior Lumbar Interbody Fusion By Finite Element Method

Lumbar vertebral as only connection between truck with pelvis burden the largest load on spine column, load gradually enlarge from supper vertebral to low lumbar vertebral. Meanwhile the movement range of lumbar vertebral is too larger than other segment, the details show that degeneration of spine usually happen on the low lumbar vertebral, in that, the research of low lumbar vertebral's biomechanical is valuable in clinic.Now, there are number kind of experiments to study spine biomechanics, four experiment methods are usually used:animal experiment, physical experiment, cadaver experiment and computersimulator experiment, they are all outside-body. Computer simulator experiment such as finite element cansimulator repeatedly. If some parameters are changed it can model degenerate of spine.This paper studied animal experiment with calf lumbar and computer simulator with FEM. The object of the research is to develop a three-dimension finite element model of L4-L5 to study the stress distribution of lumbar vertebral when human standing with different posture. By using the CAD software constitute lumbar 4-5 model and than imput Ansys 8.0 to establish elements.It composed 227,874 nodes,146,411 elements and 6 materials. It was be approved that the model were reasonable and consistent with test.This paper also studied the stress distribution of posterior lumbar interbody fusion (PLIF) lumbar 4-5 model under different loads, reinforced lumbar, implants, and so on. The isochromatic figure of lumbar was showed in this paper by set an example with 500N pulldown and lONm bend. In this paper several methods of lumbar modeling was compared.