The quantitative assessment of risk factors to overstress at adjacent segments after lumbar fusion

Removal of posterior ligaments and pedicle screws

Ho Joong Kim, Kyoung Tak Kang, seonghwan moon, Heoung Jae Chun, Hak Sun Kim, Jin Oh Park, Eun Su Moon, Bo Ram Kim, Joon Seok Sohn, Hwan Mo Lee

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

Study Design. Finite element method. Objective. To investigate the changes in the disc stress and range of motion (ROM) at adjacent segments after lumbar fusion based on whether or not pedicle screws are removed and whether or not the continuity of the proximal posterior ligament complex (PLC) is preserved. Summary of Background Data. The ablation of proximal PLC continuity and the presence of pedicle screws have been reported to affect the biomechanics at adjacent segments after lumbar fusion. However, there have been few studies regarding the quantitative assessment of their contribution to overstress at adjacent segments after lumbar fusion. Methods. In the validated intact lumbar finite element model (L2-L5), four types of L3-L4 fusion models were simulated. These models included the preservation of the PLC continuity with pedicle screws (Pp WiP), the preservation of PLC continuity without pedicle screws (Pp WoP), the sacrifice of PLC with pedicle screws (Sp WiP), and the sacrifice of PLC without pedicle screws (Sp WoP). In each scenario, the ROM, maximal von Mises stress of discs, and the facet joint contract force at adjacent segments were analyzed. Results. Among the four models, the Sp WiP yielded the greatest increase in the ROM and the maximal von Mises stress of the disc at adjacent segments under four moments. Following the SP WiP, the order of increase of the ROM and the disc stress was Pp WiP, Sp WoP, and Pp WoP. Furthermore, the increase of ROM and disc stress at the proximal adjacent segment was more than at the distal adjacent segment under all four moments in each model. The facet joint contact was also most increased in the Sp WiP under extension and torsion moment. Conclusion. The current study suggests that the preservation of the PLC continuity or the removal of pedicle screws after complete fusion could decrease the stress at adjacent segments, and their combination could act synergistically.

Original languageEnglish
Pages (from-to)1367-1373
Number of pages7
JournalSpine
Volume36
Issue number17
DOIs
Publication statusPublished - 2011 Aug 1

Fingerprint

Ligaments
Articular Range of Motion
Zygapophyseal Joint
Pedicle Screws
Biomechanical Phenomena

All Science Journal Classification (ASJC) codes

  • Orthopedics and Sports Medicine
  • Clinical Neurology

Cite this

Kim, Ho Joong ; Kang, Kyoung Tak ; moon, seonghwan ; Chun, Heoung Jae ; Kim, Hak Sun ; Park, Jin Oh ; Moon, Eun Su ; Kim, Bo Ram ; Sohn, Joon Seok ; Lee, Hwan Mo. / The quantitative assessment of risk factors to overstress at adjacent segments after lumbar fusion : Removal of posterior ligaments and pedicle screws. In: Spine. 2011 ; Vol. 36, No. 17. pp. 1367-1373.
@article{56125145db924339a6ddd7900e984300,
title = "The quantitative assessment of risk factors to overstress at adjacent segments after lumbar fusion: Removal of posterior ligaments and pedicle screws",
abstract = "Study Design. Finite element method. Objective. To investigate the changes in the disc stress and range of motion (ROM) at adjacent segments after lumbar fusion based on whether or not pedicle screws are removed and whether or not the continuity of the proximal posterior ligament complex (PLC) is preserved. Summary of Background Data. The ablation of proximal PLC continuity and the presence of pedicle screws have been reported to affect the biomechanics at adjacent segments after lumbar fusion. However, there have been few studies regarding the quantitative assessment of their contribution to overstress at adjacent segments after lumbar fusion. Methods. In the validated intact lumbar finite element model (L2-L5), four types of L3-L4 fusion models were simulated. These models included the preservation of the PLC continuity with pedicle screws (Pp WiP), the preservation of PLC continuity without pedicle screws (Pp WoP), the sacrifice of PLC with pedicle screws (Sp WiP), and the sacrifice of PLC without pedicle screws (Sp WoP). In each scenario, the ROM, maximal von Mises stress of discs, and the facet joint contract force at adjacent segments were analyzed. Results. Among the four models, the Sp WiP yielded the greatest increase in the ROM and the maximal von Mises stress of the disc at adjacent segments under four moments. Following the SP WiP, the order of increase of the ROM and the disc stress was Pp WiP, Sp WoP, and Pp WoP. Furthermore, the increase of ROM and disc stress at the proximal adjacent segment was more than at the distal adjacent segment under all four moments in each model. The facet joint contact was also most increased in the Sp WiP under extension and torsion moment. Conclusion. The current study suggests that the preservation of the PLC continuity or the removal of pedicle screws after complete fusion could decrease the stress at adjacent segments, and their combination could act synergistically.",
author = "Kim, {Ho Joong} and Kang, {Kyoung Tak} and seonghwan moon and Chun, {Heoung Jae} and Kim, {Hak Sun} and Park, {Jin Oh} and Moon, {Eun Su} and Kim, {Bo Ram} and Sohn, {Joon Seok} and Lee, {Hwan Mo}",
year = "2011",
month = "8",
day = "1",
doi = "10.1097/BRS.0b013e318221a595",
language = "English",
volume = "36",
pages = "1367--1373",
journal = "Spine",
issn = "0362-2436",
publisher = "Lippincott Williams and Wilkins",
number = "17",

}

The quantitative assessment of risk factors to overstress at adjacent segments after lumbar fusion : Removal of posterior ligaments and pedicle screws. / Kim, Ho Joong; Kang, Kyoung Tak; moon, seonghwan; Chun, Heoung Jae; Kim, Hak Sun; Park, Jin Oh; Moon, Eun Su; Kim, Bo Ram; Sohn, Joon Seok; Lee, Hwan Mo.

In: Spine, Vol. 36, No. 17, 01.08.2011, p. 1367-1373.

Research output: Contribution to journalArticle

TY - JOUR

T1 - The quantitative assessment of risk factors to overstress at adjacent segments after lumbar fusion

T2 - Removal of posterior ligaments and pedicle screws

AU - Kim, Ho Joong

AU - Kang, Kyoung Tak

AU - moon, seonghwan

AU - Chun, Heoung Jae

AU - Kim, Hak Sun

AU - Park, Jin Oh

AU - Moon, Eun Su

AU - Kim, Bo Ram

AU - Sohn, Joon Seok

AU - Lee, Hwan Mo

PY - 2011/8/1

Y1 - 2011/8/1

N2 - Study Design. Finite element method. Objective. To investigate the changes in the disc stress and range of motion (ROM) at adjacent segments after lumbar fusion based on whether or not pedicle screws are removed and whether or not the continuity of the proximal posterior ligament complex (PLC) is preserved. Summary of Background Data. The ablation of proximal PLC continuity and the presence of pedicle screws have been reported to affect the biomechanics at adjacent segments after lumbar fusion. However, there have been few studies regarding the quantitative assessment of their contribution to overstress at adjacent segments after lumbar fusion. Methods. In the validated intact lumbar finite element model (L2-L5), four types of L3-L4 fusion models were simulated. These models included the preservation of the PLC continuity with pedicle screws (Pp WiP), the preservation of PLC continuity without pedicle screws (Pp WoP), the sacrifice of PLC with pedicle screws (Sp WiP), and the sacrifice of PLC without pedicle screws (Sp WoP). In each scenario, the ROM, maximal von Mises stress of discs, and the facet joint contract force at adjacent segments were analyzed. Results. Among the four models, the Sp WiP yielded the greatest increase in the ROM and the maximal von Mises stress of the disc at adjacent segments under four moments. Following the SP WiP, the order of increase of the ROM and the disc stress was Pp WiP, Sp WoP, and Pp WoP. Furthermore, the increase of ROM and disc stress at the proximal adjacent segment was more than at the distal adjacent segment under all four moments in each model. The facet joint contact was also most increased in the Sp WiP under extension and torsion moment. Conclusion. The current study suggests that the preservation of the PLC continuity or the removal of pedicle screws after complete fusion could decrease the stress at adjacent segments, and their combination could act synergistically.

AB - Study Design. Finite element method. Objective. To investigate the changes in the disc stress and range of motion (ROM) at adjacent segments after lumbar fusion based on whether or not pedicle screws are removed and whether or not the continuity of the proximal posterior ligament complex (PLC) is preserved. Summary of Background Data. The ablation of proximal PLC continuity and the presence of pedicle screws have been reported to affect the biomechanics at adjacent segments after lumbar fusion. However, there have been few studies regarding the quantitative assessment of their contribution to overstress at adjacent segments after lumbar fusion. Methods. In the validated intact lumbar finite element model (L2-L5), four types of L3-L4 fusion models were simulated. These models included the preservation of the PLC continuity with pedicle screws (Pp WiP), the preservation of PLC continuity without pedicle screws (Pp WoP), the sacrifice of PLC with pedicle screws (Sp WiP), and the sacrifice of PLC without pedicle screws (Sp WoP). In each scenario, the ROM, maximal von Mises stress of discs, and the facet joint contract force at adjacent segments were analyzed. Results. Among the four models, the Sp WiP yielded the greatest increase in the ROM and the maximal von Mises stress of the disc at adjacent segments under four moments. Following the SP WiP, the order of increase of the ROM and the disc stress was Pp WiP, Sp WoP, and Pp WoP. Furthermore, the increase of ROM and disc stress at the proximal adjacent segment was more than at the distal adjacent segment under all four moments in each model. The facet joint contact was also most increased in the Sp WiP under extension and torsion moment. Conclusion. The current study suggests that the preservation of the PLC continuity or the removal of pedicle screws after complete fusion could decrease the stress at adjacent segments, and their combination could act synergistically.

UR - http://www.scopus.com/inward/record.url?scp=80051550123&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=80051550123&partnerID=8YFLogxK

U2 - 10.1097/BRS.0b013e318221a595

DO - 10.1097/BRS.0b013e318221a595

M3 - Article

VL - 36

SP - 1367

EP - 1373

JO - Spine

JF - Spine

SN - 0362-2436

IS - 17

ER -