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fbtwitterlinkedinvimeoflicker grey 14rssslideshare1
Publisher: Elsevier
Languages: English
Types: Article
Subjects: G900, B800, H100, H300
The present study aims to the design of a finite-element model simulating accurately the pullout behaviour of cylindrical pedicle screws and predicting their pullout force. Three commercial pedicle screws, subjected to pure pullout from synthetic bone, were studied experimentally. The results were used for the design, calibration and validation of a finite-element model. Special attention was paid to the accurate simulation of the failure inside the host material. For this purpose a bilinear cohesive zone material model was adopted to control mode-II debonding of neighbouring elements in the vicinity of the screw and simulate this way the failure in shear of the hosting material. Comparison between experimental and numerical results proved that the implementation of this method can significantly enhance the accuracy of the numerical simulation of a screw’s mechanical behaviour under pure pullout loads. The numerical model was used for the parametric study of various factors affecting the pullout performance of a cylindrical pedicle screw. It was concluded that the major parameters influencing the pullout force is the outer radius and purchase length of the screw. Significantly weaker was the dependence of the screw’s pullout force on its thread inclination, depth and pitch.
  • The results below are discovered through our pilot algorithms. Let us know how we are doing!

    • 9) Conrad B, Cordista A, Horodyski M, Rechtine GR. Biomechanical evaluation of the pullout strength of cervical screws. J Spinal Disord Tech 2005;18:506-10.
    • 10) Ansell H, Scales J. A study of some factors which affect the strength of screws and their insertion and holding power in bone. J. Biomechanics 1968;1:279-302.
    • 11) DeCoster TA, Heetderks DB, Downey DJ, Ferries JS, Jones W. Optimizing bone screw pullout force. J Orthop Trauma 1990;4(2):169-74.
    • 12) Koranyi E, Bowman C, Knecht C, Janssen M. Holding power of orthopedic screws in bone. Clinical Orthopaedics and Related Research 1970;72:283-6.
    • 13) Thompson J, Benjamin J, Szivek J. Pullout strength of cannulated and noncannulated cancellous bone screws. Clinical Orthopaedics and Related Research 1997;341:241-9.
    • 14) Hughes AN, Jordan BA. The mechanical properties of surgical bone screws and some aspects of insertion practice. Injury 1972;4:25-38.
    • 15) Zindrick M, Wiltse L, Widell E, Thomas J, Holland R, Field T, Spencer C. Biomechanical study of intrapedicular screw fixation in the lumbosacral spine. Clinical Orthopaedics and Related Research 1986;203:99-112.
    • 16) Leggon R, Lindsey RW, Doherty BJ, Alexander J, Noble P. The holding strength of cannulated screws compared with solid screws in cortical and cancelous bone. Journal of Othopaedic Trauma 1993;7:450-7.
    • 17) Gausepohl T, Möhring R, Pennig D, Koebke J. Fine thread versus coarse thread A comparison of the maximum holding power Injury. Int. J. Care Injured 2001;32:SD1-SD7.
    • 18) Krenn M, Piotrowski W, Penzkofer R, AUGAT P. Influence of thread design on pedicle screw fixation: Laboratory investigation. J Neurosurg (Spine) 2008;9:90- 5.
    • 19) Zhang QH, Tan SH, Chou SM. Investigation of fixation screw pull-out strength on human spine. Journal of Biomechanics 2004;37:479-485.
    • 20) Zhang QH, Tan SH, Chou SM. Effects of bone materials on the screw pull-out strength in human spine. Medical Engineering & Physics 2006;28:795-801.
    • 21) Gefen A. Optimizing the biomechanical compatibility of orthopaedic screws for bone fracture fixation. Medical Engineering & Physics 2002;24:337-347.
    • 22) Hsu CC, Chao CK, Wang JL, Hou SM, Tsai YT, Lin J. Increase of pullout strength of spinal pedicle screws with conical core: biomechanical tests and finite element analyses. Journal of Orthopaedic Research 2005;23:788-794.
    • 23) Chao CK, Hsu CC, Wang JL, Lin J.Increasing Bending Strength and Pullout Strength in Conical Pedicle Screws: Biomechanical Tests and Finite Element Analyses. J Spinal Disord Tech 2008;21:130-138.
    • 24) Kourkoulis SK, Chatzistergos EP. The influence of the "penetration-" and the "filling- ratios" on the pull-out strength of transpedicular screws. Journal of Mechanics in Medicine and Biology 2009;9:1-18.
    • 25) Long M, Rack HJ. Titanium alloys in total joint replacement--a materials science perspective. Biomaterials 1998;19:1621-39.
    • 26) Dimar J, Glassman S, Puno R, Campbell M, Johnson J. Posterior lumbar spine: CD Horizon Legacy 5.5 Spinal System. In Spinal instrumentation: surgical techniques. Fessler R, Kim D, Vaccaro A, eds. NY:Thieme Medical Publishers Inc,2005:850-5.
    • 27) Alfano G, Crisfield MA. Finite Element Interface Models for the Delamination Anaylsis of Laminated Composites: Mechanical and Computational Issues. International Journal for Numerical Methods in Engineering 2001;50:1701-36.
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