| dc.description.abstract | In resent years, the aging population becomes the trend in the world. With the age rising, the effect of aging and the accidents are increasing. The most common degeneration is in the lumbar intervertebral disc. Lumbar interbody fusion is usually used in the treatment of the degeneration. The fusion uses the cage to replace the degenerated disc and insert some bone graft to let the inferior/exterior intevertebarl body fuse together. The present study develops a new expandable cage to substitute for the traditional cage, and finds the differences of biomechanical behaviors between the expandable cage and traditional cage.
The software AMIRA and SolidWorks were adopted to establish the lumbar model. The L4/L5 intervertebral disc was replaced by different cages such as expandable cage, circular cage, and square cage. The biomechanical behaviors of the lumbar in the initial stage of fusion were analyzed with finite element method.
From the results, the range of motion (ROM) of pillar-spine is better than that of circular- spine in the case of extension, flexion, left-bending, and right-bending. Also, the ROM of pillar-spine is better than s that of Square-spine in the case of extension, flexion, and, right- bending. But the ROM of pillar-spine is higher in the case of left-rotation and right-rotation. The max. von Mises stress in pillar-spine is higher than the others. This study suggests that increasing the radius of the fillet to decrease the stress concentration. The degeneration of adjacent intervertebral disc is not obvious in this study. | en_US |