Publication detail

Analysis of the influence of lumbosacral fusion on the adjacent moving segment

NÁVRAT, T. ŽENČICA, P. PÁNIS, V. VOSYNEK, P. FUIS, V.

Original Title

Analysis of the influence of lumbosacral fusion on the adjacent moving segment

English Title

Analysis of the influence of lumbosacral fusion on the adjacent moving segment

Type

conference paper

Language

en

Original Abstract

The term "adjacent segment disease - ASD" is the designation for clinical degeneration of the adjacent active segment to the fused segment. This disease occurs as the subsequent complication of spinal fusion, which could result in more surgery. The fusion spine segment significantly reduces movement which causes load enhancement in adjacent active segments and causes a change of mobility. The changes are probably the primary cause of the occurrence of ASD. The strongest degeneration occurs at the nearest point under or above the fusion. The purpose of this work was to analyze the loading of the adjacent disc to the fused segment for flexion and extension movement of the whole segment. The problem was comprehensively solved using complex experimental and computational modeling. Thanks to experimental measurement we recorded the re-sponse of the test specimen to flexion and extension movement. The test sample was composed of three vertebrae and two discs. The specimens were taken from a pig. Two states were modeled: healthy and damaged with a LEGACY implant. In healthy specimens the deformation mainly takes place in the disc. In the case of the fusion of two vertebrae with the same loading the deformation mainly take place on an adjacent disc. One way to determine the state of stress inside discs is by computational modeling. The strain-stress states were done by solving the computational model in the ANSYS system. Two variants were solved: healthy and damaged with a LEGACY implant. The model was loaded by angular displacement according to flexion and extension movement. The most important findings are: the specimen with the fused segment has significantly higher stiffness compared to the healthy specimen. The disc above the fused segment treated with LEGACY is more loaded (higher stresses) in flexion than in the healthy specimen.

English abstract

The term "adjacent segment disease - ASD" is the designation for clinical degeneration of the adjacent active segment to the fused segment. This disease occurs as the subsequent complication of spinal fusion, which could result in more surgery. The fusion spine segment significantly reduces movement which causes load enhancement in adjacent active segments and causes a change of mobility. The changes are probably the primary cause of the occurrence of ASD. The strongest degeneration occurs at the nearest point under or above the fusion. The purpose of this work was to analyze the loading of the adjacent disc to the fused segment for flexion and extension movement of the whole segment. The problem was comprehensively solved using complex experimental and computational modeling. Thanks to experimental measurement we recorded the re-sponse of the test specimen to flexion and extension movement. The test sample was composed of three vertebrae and two discs. The specimens were taken from a pig. Two states were modeled: healthy and damaged with a LEGACY implant. In healthy specimens the deformation mainly takes place in the disc. In the case of the fusion of two vertebrae with the same loading the deformation mainly take place on an adjacent disc. One way to determine the state of stress inside discs is by computational modeling. The strain-stress states were done by solving the computational model in the ANSYS system. Two variants were solved: healthy and damaged with a LEGACY implant. The model was loaded by angular displacement according to flexion and extension movement. The most important findings are: the specimen with the fused segment has significantly higher stiffness compared to the healthy specimen. The disc above the fused segment treated with LEGACY is more loaded (higher stresses) in flexion than in the healthy specimen.

Keywords

adjacent segment disease, experimental and computational modeling, FEM

RIV year

2010

Released

01.08.2010

Publisher

SPRINGER, 233 SPRING STREET, NEW YORK, NY 10013, UNITED STATES

Location

Singapur

ISBN

978-3-642-14514-8

Book

6th World Congress of Biomechanics

Pages from

811

Pages to

814

Pages count

4

BibTex


@inproceedings{BUT35717,
  author="Tomáš {Návrat} and Pavel {Ženčica} and Vladimír {Pánis} and Petr {Vosynek} and Vladimír {Fuis}",
  title="Analysis of the influence of lumbosacral fusion on the adjacent moving segment",
  annote="The term "adjacent segment disease - ASD" is the designation for clinical degeneration of the adjacent active segment to the fused segment. This disease occurs as the subsequent complication of spinal fusion, which could result in more surgery. The fusion spine segment significantly reduces movement which causes load enhancement in adjacent active segments and causes a change of mobility. The changes are probably the primary cause of the occurrence of ASD. The strongest degeneration occurs at the nearest point under or above the fusion. The purpose of this work was to analyze the loading of the adjacent disc to the fused segment for flexion and extension movement of the whole segment. The problem was comprehensively solved using complex experimental and computational modeling. Thanks to experimental measurement we recorded the re-sponse of the test specimen to flexion and extension movement. The test sample was composed of three vertebrae and two discs. The specimens were taken from a pig. Two states were modeled: healthy and damaged with a LEGACY implant. In healthy specimens the deformation mainly takes place in the disc. In the case of the fusion of two vertebrae with the same loading the deformation mainly take place on an adjacent disc. One way to determine the state of stress inside discs is by computational modeling.  The strain-stress states were done by solving the computational model in the ANSYS system. Two variants were solved: healthy and damaged with a LEGACY implant. The model was loaded by angular displacement according to flexion and extension movement. The most important findings are: the specimen with the fused segment has significantly higher stiffness compared to the healthy specimen. The disc above the fused segment treated with LEGACY is more loaded (higher stresses) in flexion than in the healthy specimen.",
  address="SPRINGER, 233 SPRING STREET, NEW YORK, NY 10013, UNITED STATES",
  booktitle="6th World Congress of Biomechanics",
  chapter="35717",
  howpublished="online",
  institution="SPRINGER, 233 SPRING STREET, NEW YORK, NY 10013, UNITED STATES",
  year="2010",
  month="august",
  pages="811--814",
  publisher="SPRINGER, 233 SPRING STREET, NEW YORK, NY 10013, UNITED STATES",
  type="conference paper"
}