Journal of Biomedical Engineering Research (대한의용생체공학회:의공학회지)

The Korean Society of Medical and Biological Engineering (대한의용생체공학회)
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Mechanical Characterization of the Pedicle Screw System for Thoracolumbar Spine

흉요추용 척추경 나사못시스템의 기계적 특성

  • Published : 2002.02.01
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Abstract

The purpose of this study was to investigate the important Parameters of the Pedicle screw by estimating the mechanical characteristics of screws under static and dynamic loads. Methodology for estimating Parameters under static load was proposed. It was also shown that the fatigue life of the one-level system could be increased by changing the shape of screws. Load parameters of the single pedicle screw were friction force. bending moment. and holding force. The test results of the one-level system could be inferred from teat results of the sin91e screw under bending force Fatigue life of the one-level system with flexible rod was longer than that of the upper Part test without rod . Considering the drop of flexibility of the rod due to muscles and ligament, fatigue life of the one-level system could be estimated b? that of the single screw.

본 연구의 목적은 척추 내고정 시스템인 척추경 나사못의 기계적 특성 평가를 통하여 내고정 시스템에 영향을 미치는 주요 하중요소를 규명하고. 하중요소에 대한 정하중 평가와 단분절 시스템(one bevel system)에서의 피로수명을 증가시키는 방법을 제안하는 것이다. 정하중 시험에서 단일 척추경 나사못(single pedicle strew)에 작용하는 하중요소는 마찰력((friction force), 굽힘력(bending force), 결합력(holding force)으로 나타났으며, 단일 나사못의 굽힘력 시험결과로부터 단분절 시스템에 대한 시험결과의 유추가 가능하였다 척추 내고정 시스템의 상부 부분 시험의 피로수명 보다는 봉(rod)의 유연성을 포함하는 단분절 시스템에서의 피로수명이 길게 나타났고. 인체에 삽입되는 척추경 나사못 단분절 시스템에서 근육 및 ligament 등에 의해서 봉의 유연성 저하를 가져올 수 있음을 고려할 때. 단일 나사못 피로시험만으로 단분절 시스템의 피로수명 예측이 가능함을 보였다.

Keywords

References

  1. Injury v.26 Bone deformation by thread-cutting and thread forming cortex screws A. Kuhn;T. Mc Iff;J. Cordey;F.W. Baumgart;B.A. Rahn
  2. Bio-mateirals v.18 Pull out strength of fixation screws from polymethylmethacrylate bone cement C.M. Flahiff;G.A. Gorber;R.W. Nicholas
  3. Clinical Biomechanics v.13 Biomechanical evaluation of a central rod system in the treatment of scoliosis C.L. Liu;H.C. Kao;S.T. Wang;W.H. Lo;C.K. Cheng https://doi.org/10.1016/S0268-0033(98)00018-7
  4. J. Biomechanics v.30 no.1 Loads on an internal spinal fixation device during walking A. Rohlmann;G. Bergmann;F. Graichen
  5. J. Biomechanics v.1 Placing a bone graft more posteriory may reduce the risk of pedicle screw breakage:analysis of an unexpected case of pedicle screw breakage A. Rohlmann;G. Bergmann;F. Graichen;H.M. Mayer
  6. Spine v.22 no.14 Mechanical stability of thoracolumbar pedicle screw fixation: The effect of crosslinks G. Lynn;D.P. Mukherjee;R.N. Kruse;K.K. sadasivan;J.A. Albright
  7. Spine v.17 no.3S Mechanical stability of the pedicle screw fixation systems for the lumbar spine M. Yamagata;H. Kitahara;Shohei;Minami;K. Takahashi;K. Isobe;H. Moriya
  8. J. Biomechanics v.30 no.9 Loading of pedicle screws within the vertebra S.A. Yerby;J.R. Ehteshami;R.F. McLain https://doi.org/10.1016/S0021-9290(97)00037-7
  9. Clinical Biomechanics v.13 no.1 Stiffness between different direction of transpedicular screws and vertebra S.S. Wu;W.T. Edwards;H.A. Yuan https://doi.org/10.1016/S0268-0033(97)00069-7
  10. Proceeding of the 25th KOSOMBE 2001 Fall Annual Meeting Fatigue characteristic of semi-rigid screw system for spinal fixation H.J. Lee;S.I. Bae;H.S. Choi;M.H. Ahn;J.I. Song
  11. J. Biomechanics Three dimensional mathematical model of the human spine structure M.M. Panjabi;K.K. Abumi;J.S. Duranceau
  12. J. Bone and Joint Surgery v.76A-3 Mechanical behavior of the human lumbar and lumbosacral spine as shown by three-dimensional load displacement curves M.M. Panjabi;K.K. Abumi
  13. Scoliosis Research Society Inter forces and moments in transpedicular spine instrumentation-the effect of pedicle screw angle and transfixation-the 4R-4Bar linkage concept L. William