隨著醫療技術的進步，人口老化已是世界的趨勢。隨著年紀的攀升人體老化的情況與意外事故的發生也隨之增加。其中尤以腰椎椎間盤的退化最為常見。醫療手術中治療腰椎椎間盤退化通常是使用脊椎融合術，融合術是擺入椎籠替代原本退化的椎間盤 並植入骨粉將上下兩塊椎骨融合成一塊椎骨。本篇研究是新設計一種可撐開式的椎籠取代傳統椎籠探討其生物力學行為，觀察是否能比傳統椎籠更有其優勢。 本篇研究使用AMIRA與SolidWorks建立L3-L5腰椎模型，並移除L4/L5椎間盤置入不同形式之椎籠(可撐式椎籠、一般圓椎籠、一般方椎籠)，再以ANSYS Workbench進行有限元素分析，探討其融合初期之生物力學行為。 結果顯示可撐式椎籠之運動範圍(ROM)值在後仰、前彎、左彎及右彎表現上都比同外型尺寸的圓椎籠好；在後仰、前彎與右彎的表現比方椎籠好。可撐式椎籠抵抗扭轉能力較差，ROM較大。可撐式椎籠最大應力值高於圓椎籠與方椎籠，可考慮在應力集中處的凹槽底部增大曲率半徑，以降低應力。可撐式椎籠造成的鄰近椎間盤應力值提升不明顯，較不會導致鄰近椎間盤退化。 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.
