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研究生：	陳守義 Shou-I, Chen
論文名稱：	椎弓骨釘在材料性質及介面狀態之生物力學分析 Biomechanical Analysis of the Transpedicular Screw on Material Property and Interface Condition
指導教授：	林瑞模 Lin, Ruey-Mo 張志涵 Chang, Chih-Han
學位類別：	博士 Doctor
系所名稱：	工學院 - 醫學工程研究所 Institute of Biomedical Engineering
論文出版年：	2003
畢業學年度：	91
語文別：	中文
論文頁數：	66
中文關鍵詞：	生物力學、椎弓骨釘、有限元素法、腰椎、內固定器
外文關鍵詞：	finite element method, internal fixation device, pedicle screw, biomechanics
相關次數：	點閱：83 下載：4
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對於脊椎不穩定或是下背痛的患者，臨床上以外科手術進行治療已是一普遍採行的方法，在手術中常以金屬內固定器系統進行固定以得到患部術後立即而穩定之效果，協助不穩定椎節癒合。此類固定手術造成失敗的原因包括：固定效果不佳、椎體與骨釘介面局部的破壞、骨釘的斷裂…等，對於上述問題有許多學者利用臨床的資料或實驗方法進行探討，本研究將針對脊椎後固定器的椎弓骨釘植入腰椎的部分，做生物力學傳導機轉的探討。研究中將結合CAD系統及有限元素方法，建立椎弓骨釘植入腰椎的三維有限元素模型，此模型在脊椎之幾何外形上與人體相近，並能表現出骨骼較非均質分佈的材料特性，將分別探討不同的骨釘長度、兩種極端之椎體生理條件(flexion 和extension)、椎弓骨釘與椎體之交界面情形(bonded interface和contact interface)、股釘的材料（鈦合金及不鏽鋼合金）、不同等級骨質疏鬆的腰椎骨質情形…等因素，對骨釘及椎體力學的影響。
骨釘承受的負荷整體而言為一彎曲負荷，在接觸界面應力分佈上可以發現有四個主要接觸點將骨釘的負荷傳遞至腰椎部分，椎弓骨釘的最大主應力集中在骨釘與螺紋交界的區域，此區域與臨床上發現骨釘斷裂的位置相吻合；兩種極端之椎體生理負荷(flexion 和extension)對骨釘與腰椎力學傳的影響，主要因為椎體幾何外形的因素所造成。當骨釘的長度超過腰椎之椎體與椎弓交界區域時，椎弓骨釘的長度與骨釘應力大小影響較不明顯；在骨釘與椎體界面情形，因為bonded能傳導張應力，所以能使骨釘與椎體界面間較均勻的將負荷傳導至椎體，其骨釘螺紋交界處的應力也較接觸界面的情形小，因此臨床上使用HA或其他方式增加骨釘與骨骼交界面之結合情形，並使用足夠長的骨釘，將可有效降底骨釘斷裂的可能性。另外在骨釘與椎體材料變化方面，不鏽鋼合金的骨釘與骨質疏鬆的腰椎，均會加增骨釘與螺紋交界處的應力值，如此而提高骨釘斷裂的可能性。本研究期望透過電腦分析，對於影響骨釘與椎體應力傳導的各參數進行探討，提供臨床醫師及椎弓骨釘固定系統設計時的參考，進而改善臨床治療及服務的品質。

Pedicle screw fixation systems are commonly used in orthopedic surgical procedures to treat unstable spines. Recent clinical surveys have reported that the major failure modes of the pedicle screw fixation system are screw failure and vertebral body breakage. To avoid these failures, better understanding of the mechanical environment within the body and the implanted screws is essential. This study used finite element simulation to investigate the load transfer mechanisms within the screw/vertebra complex under different interface conditions, under varying screw lengths, and the material property of the screw and vertebrae. Both bonded and contact conditions were employed to demonstrate the interface between the screw and vertebra. Loadings were applied at the superior surface of the vertebra and screw unthreaded end respectively to represent two modes of flexion loads. Two material property of the screw (stainless, titanium) and osteoporostic vertebrae were assigned in FE model.
The results indicated that the screw within the vertebra underwent a series of discontinuities of loading, identified by the localized high contact pressures, thus creating localized bending moments. The peak stress of screw was located at the junction of the screw`s hub and thread, which is consistent with the location of screw failure observed in a clinical setting and the values of peak stress in the screw were propertional to the amount of moments generated by the two loading modes.
The interface condition plays an important role in transferring the force within the screw/vertebra complex. A contact interface condition induces significantly higher stress in the screw than the bonded condition. Therefore providing a binding surface (with HA, or porosity coating on the screw surface) between the screw and the vertebra might be the most effective way to prevent screw failure.
The influences of screw length on the peak stress in the screw become negligible when the screw is of sufficient length to extend fully into the vertebral body. The stress at the screw/thread junction for titanium screw could be decreased but companied by the increasing of displacement, which might induce a unstable outcome. The screw stresses were increased within the osteoporotic vertebrae, which include a high risk of screw failure. However, the screw might be pullout prior to its failure due to the increased strain in the osteoporotic vertebrae.

CHINESE ABSTRACT	                   I
ENGLISH ABSTRACT                    III
誌謝	                            V
CONTENTS	                           VI
LIST OF FIGURES	                 VIII
LIST OF TABLES	                  XI
	
CHAPTEER	
INTRODUCTION.........................................................	1
1 The spine of human...................................................................	1
1.1 The characteristic of the vertebrae............................................................	1
1.2 The characteristic of the pedicle................................................................	3
2 Problems and background..........................................................	5
2.1 The history of the inertial fixation system...............................................................	5
2.2 The complications of the fixation system................................................................	6
3 Literature review of the internal fixation system……...........................................................	8
3.1 Experimental studies............................................................	8
3.2 Numerical studies..............................................................	10
4 Finite element application in the biomechanical study.......	14
5 Hypotheses and objectives of the present study.................................................................	15
	
MATERIALS AND METHODS................................................................	16
1 Mesh with the virtual implantation of Screw................................................................	16
1.1 Image processing..............................................................	17
1.2 Simulation of the implantation procedure...........................................................	18
1.3 Three-dimension finite element mesh generation...................	18
1.4 Material property of the vertebra determined from the CT image.	21
1.5 Bonded and contact interface between the screw and vertebrae....	21
	
2 Loading and boundary conditions..............................................................	23
3 Screw lengths and interface condition.............................................................	25
4 The material properties of the screw and vertebrae............................................................	27
	
	
RESULTS............................................................	30
1 The Assumption of the finite element model...............................................................	30
1.1 The pilot study of the two-segment motion unite..............................................................	30
1.2 The friction coefficient assignment...........................................................	32
2 Finite element results of the pedicle screw..............................................................	33
2.1 The deflection and stress distributions in the screw................................................................	33
2.2 Screw response of different loading cases, interface condition and screw length...............................................................	34
2.3 Screw response of different loading cases, interface condition, and Material property..................................................	41
	
DISCUSION........................................................	44
1 The mechanism of load transfer.................................................................	44
2 Stress distributions in screw.................................................................	47
3 Stress distributions in vertebrae...........................................................	49
4 Effects of screw length................................................................	50
5 Effect of the material property of the screw and vertebrae........................................................	51
6 Clinical relevance.............................................................	54
7 Model mitations......................................................	56
	
CONCLUSIONS AND FUTURE WORKS........................……..............	58
1 Conclusions……………………………………………………………...	58
2 Future works……………………………………………………………..	59
	
REFERENCES........................................................	61
                                    

Ashman BB, Birch JG, Bone LB, Corin JD, Herring JA, Johnston CE, Ritterbush JF, Roach JW. Mechanical testing of spinal instrumentation. Clinical Orthopedic and Related Research 1988;227:113-126.

Ashman RB, Galpin RD, Corin JP, Johnston CE. Biomechanical analysis of pedicle screw instrumentation systems in a corpecotomy model. Spine 1989; 14:1398-1405.

Brantley AGU, Mayfield JK. The effect of pedicle screw fit - an in vitro study. Spine 1994;19:1752-1758.

Chang C.H. Computer aided analysis of femoral stem prosthesis. Ph.D. Thesis, Rice University, USA, 1990

Cunningham BW, Sefter JC, Shono Y, McAfee PC. Static and cyclical biomechanical analysis of pedicle screw spinal constructs. Spine 1993;18:1677-1688.

Carl AL, Tromanhauser SG, Roger DJ. Pedicle screw instrumentation for thoracolumbar burst fractures and fracture-dislocations. Spine 1992;17: 317S-324S.

Duffield RC, Carson WL, Chen LY, Voth B. Longitudinal element size effect on load sharing, internal loads, and fatigue life of tri-level spinal implant constructs. Spine 1993;18:1695-1703.

Damkot DK, Pope MH, Load J, Frymoyer JW. The relationship between work history, work environment and low-back pain in men. Spine 1984, 9:395-399.

Esses SI, Sachs BL, Dreyzin V. Complications associated with the technique of pedicle screw fixation - a selected survey of ABS members. Spine 1993; 18:2231-2239.

Emine, C., Aydinlik, E. Effect of a dilacerated root on stress distribution to the tooth and supporting tissues. Journal of Prosthetic Dentistry, 1991, 65: 771.

Ebelke DK, Asher MA, Neff JR, Krake DP. Survivorship analysis of VSP spine instrumentation in the treatment of thoracolumbar and lumbar burst fractures. Spine 1991;16:428S-432S.

Greenfield RT, Capen DA, Thomas TC, Nelson R, Nagelberg S, Rimoldi RL, Haye W. Pedicle screw fixation for arthrodesis of the lumbosacral spine in the elderly - an outcome study. Spine 1998;23:1470-1475.

Goel, V.K., Khera, S.C., Gurusami, S.A. & Chen, R.C.S. Effect of cavity depth on stresses in a restored tooth. Journal of Prosthetic Dentistry, 1992, 67: 174.

Gaines RW, Carson WL, Satterlee CC, Groh GI. Experimental evaluation of seven different spinal fracture internal fixation devices using nonfailure stability testing - the load-sharing and unstable-mechanism concepts. Spine 1991; 16:902-909.

Harrington PR, Tullos HS. Reduction of severe spondylolisthesis in children. South Med J 1969;62:1-7.

Hirano T, Hasegawa K, Takahashi HE, Uchiyama S, Hara T, Washio T, Sugiura T, Yokaichiya M, Ikede M. Structural characteristics of the pedicle and its role in screw stability. Spine 1997;22:2504-2510.

Hirabayashi S, Kumano K, Kuroki T. Cotrel-Dubousset pedicle screw system for various spinal disorders - merits and problems. Spine 1991;16:1298-1304.

Jeffrey MS. Applied finite element modeling. Marcel dekker inc., 1989.

Krag MH, Weaver DL, Beynnon BD. Morphometry of the thoracic and lumbar spine related to transpedicular screw placement for surgical spinal fixation. Spine 1988; 13:27-32.

Krag MH. Biomechanics of thoracolumbar spinal fixation - a review. Spine 1991; 16:84S-99S.

Lim TH, Kim JG, Fujiwara A, Yoon TT, Lee SC, Ha JW, An HS. Biomechanical evaluation of diagonal fixation in pedicle screw instrumentation. Spine 2001; 26(22):2498-503.

Lim TH, Eck JC, An HS, Hong JH, Ahn JY, You JW. Biomechanics of transfixation in pedicle screw instrumentation. Spine 1996;21:2224-2229.

Lim TH, Goel VK, Weinstein JN, Kong W. Stress analysis of a canine spinal motion segment using the finite element technique. J. Biomechanics 1994;27:1259-1269.

McKinley TO, McLain RF, Yerby SA, Sharkey NA, Sarigul-Klijn N, Smith TS. Characteristics of Pedicle Screw Loading Effect of Surgical Technique on Intravertebral and Intrapedicular Bending Moments. Spine 1999;24:18-24.

Matsuzaki H, Tokuhashi Y, Matsumoto F, Hoshino M, Kiuchi T, Toriyama S. Problems and solutions of pedicle screw plate fixation of lumbar spine. Spine 1990;15:1159-65.

McAfee PC, Weiland DJ, Carlow JJ. Survivorship analysis of pedicle spinal instrumentation. Spine 1991;16:422S-427S.

McLain RF, Sparling E, Benson DR. Early failure of short-segment pedicle instrumentation for thoracolumbar fractures. J Bone Joint Surg [Am] 1993;75:162-167.

McLain RF, McKinley TO, Yerby SA, Smith TS, Sarigul-Klijn N. The effect of bone quality on pedicle screw loading in axial instability - A synthetic model. Spine 1997;22:1454-1460.

McKinley TO, McLain RF, Yerby SA, Sarigul-Klijn N, Smith TS. The effect of pedicle morphometry on pedicle screw loading - a synthetic model. Spine 1997; 22:246-252.

Maiman DJ, Pintar F, Yoganandan N, Reinartz J. Effects of anterior vertebral grafting on the traumatized lumbar spine after pedicle screw-plate fixation. Spine 1993;18:2423-2430.

Polly DW, Orchowski JR, Ellenbogen RG. Revision pedicle screws bigger, longer, shims - what is best ? Spine 1998;23:1374-1379.

Panjabi MM, Duranceau J, coel V. Cervical human vertebrae: Quantitative three-dimensional antomy of the middle and lower regions. Spine 1991; 16:861-869.

Pihlajamaki H, Myllynen P, Bostman O. Complications of transpedicular lumbosacral fixation for non-traumatic disorders. British Editorial Society of Bone and Joint Surgery 1997;79-B:183-189.

Pearcy MJ, Tibrewal S. Axial rotation and lateral bending in the normal lumbar spine measured by three-dimensional radiography. Spine 1984; 9:582-587.

Roy-Camille R, Sailant G, Mazzel C. Internal fixation of the lumbar spine with pedicle screw plating. Clinical Orthopedic and Related Research 1986; 203:7-17.

Rho JY, Zerwekh JE, Ashman RB. Examination of several techniques for predicting trabecular elastic modules and ultimate strength in the human lumbar spine. Clinical Biomechanics 1994;9:67-71.

Rho JY, Hobatho MC, Ashman RB. Relations of mechanical properties to density and CT numbers in human bone. Med. Eng. Phys. 1995;17:347-355.

Roger CD, William LC, Chen LY, Brian V. Longitudinal element size effect on load sharing, internal loads, and fatigue life of tri-level spinal implant constructs. Spine 1993; 18:1695-1703.

Soini J,Laine T, Pohjolainen T, Rikki H, Alaranta H. Spondylodesis augmented by transpedicular fixation in the treatment of olisthetic and degenerative condition of the lumbar spine. Clinical Orthopedic and Related Research 1993;297:111-116.

Skinner R, Maybee J, Transfeldt E, Venter R, Chalmers W. Experimental pullout testing and comparison of variables in transpedicular screw fixation - a biomechanical study. Spine 1990;15:195-201.

Skalli W, Robin S, Lavaste F, Dubousset J. A biomechanical analysis of short segment spinal fixation using a three-dimensional geometric and mechanical model. Spine 1993;18:536-545.

Van C, Mow WC. Basic orthopedic biomechanics. 1991 by Raven Press, Ltd.

Youssef JA, McKinley TO, Yerby SA, McLain RF. Characteristics of pedicle screw loading effect of sagittal insertion angle on intrapedicular bending moments. Spine 1999;24:1077-1081.

Yerby SA, Ehteshami JR, McLain RF. Loading of pedicle screws within the vertebra. J. Biomechanics 1997;30:951-954.

Yahiro MA. Comprehensive literature review-pedicle screw fixation devices. Spine 1994;19:2274S-2278S.

Zdeblick TA, Kunz DN, Cooke ME, McCabe R. Pedicle screw pullout strength correlation with insertional torque. Spine 1993;18:1673-1676.

Zindrick MR, Wiltse LL, Doornik A. Analysis of the morphometric characteristics of the thoracic and lumbar pedicles. Spine 1987; 12:160-166.

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校外：2003-08-29公開

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