當脊椎的椎間盤受損時，骨科醫師進行椎間空間的重建手術，常會用椎籠加上外加的輔助固定，並配合骨融合做為穩定脊椎之功能，常用的外加固定方法有前方板型固定器和後方椎弓根骨螺絲系統。目前很多研究多著重在植入物的螺絲破壞強度研究，這些研究成果改善植入物失效的可能性，但是臨床上椎骨與椎間盤的損壞情況少有研究探討。
本研究主要針對一種獨立椎籠(Anchored spacer)與常見的脊椎前後方固定方法(ALIF、PLIF)，此三種固定方法使用於L4/L5椎間盤切除術，對於鄰近節脊椎的影響，經由四種三維模型包含:完整腰椎、獨立固定、ALIF、PLIF，並使用常見的前彎、後彎、側彎、旋轉運動進行分析，找出脊椎固定後可能的損壞部位。
分析結果顯示，在同樣的力量負載情況下，PLIF的固定穩定度最佳，但是會增加L3/L4椎間盤和下節L5椎骨的額外負擔；ALIF的固定穩定度最差，且會增加上下節L4、L5椎骨的負擔，但是椎間盤的總應能與完整腰椎最接近；Anchored spacer的固定穩定度介於ALIF與PLIF之間，特性與ALIF比較接近，對下L5椎骨的負擔比ALIF小。在相同的運動活動度下，PLIF會使椎體與椎間盤有最大的應變能增加量，增加量最多的部位在L5椎體與L3/L4椎間盤；ALIF的椎體與椎間盤應變能增加量，是三種固定器中最小者，負擔主要集中在L5椎體與L5/S1椎間盤；Anchored spacer則是介於ALIF與PLIF之間。因此同時考慮穩定度與鄰近節的應變能變化情況，Anchored spacer是一個可以考慮的手術選擇。

The discectomy and interbody fusion surgery are used to treat degenerative disc disease. The surgical operations usually use cages and additional fixation devices to stablize the fusion vertebrae. The common fixation devices were applied including anterior plates or posterior pedicle screw system. There are many studies to improve implants’ strength recently. Those studies reduced the possibility of implant failure, but little studies mention the adjacent disc disease or the adjacent vertebral fracture.
Our study developed finite element models of L1-S1 multi-level lumbar spine to investigate the biomechanical performances of the spine with three types of lumbar fusion devices at L4/L5 disc. Those devices included PLIF(cages plus posterior pedicle screw system), ALIF(cages plus anterior plate), and stand-alone cage (Anchored spacer). Four types of loading conditions were applied to investigate the biomechanical performances of each fusion devices including flexion, extension, lateral bending, and torsion.
The results showed that, PLIF is the most stable fusion type, but it would increase the strain energy on L3/L4 disc and L5 vertebra; ALIF is the most instable fusion type, and it would increase the strain energy on L5/S1 disc and L5 vertebra. The stability of Anchored spacer was between PLIF and ALIF. The increment of strain energy was also between PLIF and ALIF, and the strain energy occurred on L5/S1 disc and L5 vertebra.
In conclusion, if we consider stability and increment of strain energy of fusion type at the same time, the Anchored spacer may be a suggested option for lumbar interbody fusion.

[1] 瑜珈體位法. http://www.anandamarga.tw/main02_2.htm
[2] Glenn R. Buttermann, Brian P. Beaubien, , Andrew L. Freeman, ,James E. Stoll, James L. Chappuis, “Interbody device endplate engagement effects on motion segment biomechanics,” Journal of The Spine Journal ,Volume 9 ,pp. 564–573(2009)
[3] 林建宇，「不同設計之前為腰椎椎間融合器之有限元素分析」，碩士論文，國立中原大學，桃園 (2006)。
[4] Matti Scholz, Phillip M. Reyes, Philipp Schleicher, Anna G. U. Sawa, Seungwon Baek, Frank Kandziora, Frederick F. Marciano, Neil R. Crawford, “A New Stand-Alone Cervical Anterior InterbodyFusion Device” Journal of SPINE, Volume 34, Number 2, pp 156–160 (2009)
[5] Synthes Spine, West Chester, PA, USA，SynFix-LR System. Instruments and implants for stand-alone anterior lumbar interbody fusion (ALIF) Technique Guide.
[6] 華人脊椎線上http://www.spine-online.com.tw/index.php
[7] 頸椎構造圖 http://zh.wikipedia.org/wiki/%E9%A0%B8%E6%A4%8E
[8] Netter F.H. ," Atlas of Human Anatomy. 2nd ed.," ICON Learning Systems,(2002)
[9] 骨骼系統解剖圖. http://www.konjia.com/html/64/n-107464-3.html.
[10] ALIF手術過程. http://www.doereport.com/generateexhibit.php?ID=19272.
[11] PLIF、ALIF手術過程.http://www.doereport.com/generateexhibit.php?ID=1578
[12] Chen-Sheng Chen , Cheng-Kung Cheng , Chien-Lin Liu , Wai-Hee Lo , “Stress analysis of the disc adjacent to interbody fusion in lumbar spine” Journal of Medical Engineering & Physics ,Volume 23, pp 483–491 (2001)
[13] Steven Lau, Khai S. Lam,“ Lumbar stabilisation techniques” Journal of Current Orthopaedics ,Volume 21, pp 25–39 (2007)
[14] David A. Levin, James J. Hale, and John A. Bendo, “Adjacent Segment Degeneration Following Spinal Fusion for Degenerative Disc Disease” Bulletin of the NYU Hospital for Joint Diseases ,Volume 65(1) , pp 29-36(2007)
[15] Tiruveedhula S. Madhu “Posterior and anterior lumbar interbody fusion” Journal of Current Orthopaedics, Volume 22, pp 406-413(2008)
[16] Matti Scholz, Phillip M. Reyes, Philipp Schleicher, Anna G. U. Sawa, Seungwon Baek, Frank Kandziora, Frederick F. Marciano, and Neil R. Crawford “A New Stand-Alone Cervical Anterior Interbody Fusion Device” Journal of SPINE Volume 34, Number 2, pp 156–160 (2009)
[17] Shih-Hao Chen, Zheng-Cheng Zhong, Chen-Sheng Chen,Wen-Jer Chen, Chinghua Hung“ Biomechanical comparison between lumbar disc arthroplasty and fusion” Journal of Medical Engineering & Physics ,Volume 31,pp 244–253 (2009)
[18] Glenn R. Buttermann, Brian P. Beaubien, Andrew L. Freeman,James E. Stoll, James L. Chappuis, “Interbody device endplate engagement effects on motion segment biomechanics” Journal of The Spine Journal ,Volume 9,pp 564–573(2009)
[19] Chul-Bum Cho, Kyeong-Sik Ryu, Chun-Kun Park,“ Anterior Lumbar Interbody Fusion with Stand-Alone Interbody Cage in Treatment of Lumbar Intervertebral Foraminal Stenosis : Comparative Study of Two Different Types of Cages” Journal of Korean Neurosurg Soc, Volume 47 ,pp352-357( 2010)
[20] Anil Sethi, Aditya M. Muzumdar, Aditya Ingalhalikar, Rahul Vaidya, “ Biomechanical analysis of a novel posterior construct in a transforaminal lumbar interbody fusion model an in vitro study” Journal of The Spine Journal , Volume 11 ,pp863–869(2011)
[21] Wilsa M. S. Charles Malveaux, and Alok D. Sharan“ Adjacent Segment Disease After Lumbar Spinal Fusion: A Systematic Review of the Current Literature”, Journal of Spine Surgery, Volume 23,pp 266-274 (2011)
[22] William R. Sears, Ioannis G. Sergides, Noojan Kazemi, , Mari Smith, Gavin J. White, Barbara Osburg, “Incidence and prevalence of surgery at segments adjacent to a previous posterior lumbar arthrodesis” ,Journal of The Spine Journal , Volume 11,pp11–20 (2011)
[23] A. Marsol-Puig, R. Huguet-Comelles, J. Escala-Arnau, J. Giné-Gomà, “ Incidence and risk factors of adjacent disc degeneration after lumbar fusion”, Journal of Rev esp cir ortop traumatol., Volume 55(3),pp 170-174(2011)
[24] Synthes Spine, West Chester, PA, USA，ATB Anterior Tension Band Plate，Surgical technique
[25] Zimmer Spine,Austin, Texas, USA，InCompass Spinal Fixation System，Surgical Technique
[26] Memphis, TN, USA，LT cage Lumbar Tapered Fusiom Device，Surgical Technique
[27] Yang-Hwei Tsuang,Yueh-Feng Chiang, Chih-Yi Hung, Hung-WenWei ,Chang-Hung Huang, Cheng-Kung Cheng, ,“ Comparison of cage application modality in posterior lumbar interbody fusion with posterior instrumentation—A finite element study”, Journal of Medical Engineering &Physics ，Volume 31,pp 565–570,(2009)
[28] 實威國際, “ SolidWorks Simulation原廠教育訓練手冊”,易習圖書,(2011)
[29] 劉啟台力學教室http://sunrise.hk.edu.tw/~hmliu/1-lct/home.htm
[30] Justin E. Brier-Jones, Daniel K. Palmer, Serkan Inceoglu, Wayne K. Cheng, “Vertebral body fractures after transpsoas interbody fusion procedures” Journal of The Spine Journal ，Volume 11,pp 1068–1072,(2011)
[31] 曾姿綺, 「應用有限元素分析與工程演算法於脊椎前方板型固定器之彎曲強度研究」, 碩士論文，國立臺灣科技大學，台北(2011).