In vitro biomechanical study to quantify range of motion, intradiscal pressure, and facet force of 3-level dynamic stabilization constructs with decreased stiffness

Joseph K. Lee, Jaime A. Gomez, Christopher Michelsen, Yongjung Kim, Mark Moldavsky, Suresh Reddy Chinthakunta, Saif Khalil

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Study Design: An in vitro biomechanical study. Objective: To perform in vitro biomechanical testing on a lumbar spine using a 6-degree-of-freedom machine. To compare the range of motion (ROM), intradiscal pressure, and facet force of different 3-level dynamic stabilization constructs with traditional rigid constructs. To determine the effect of decreasing the stiffness of the dynamic construct on the various parameters. Summary of Background Data: Dynamic stabilization systems are a surgical option that may minimize the development of adjacent segment disease. Methods: Seven T12-S1 specimens were tested at ±7.5 Nm in flexion-extension, lateral bending, and axial rotation. The testing sequence was (1) intact, (2) intact with facet sensors, (3) L3-S1 rigid (3R), (4) L3-L4 dynamic and L4-S1 rigid (1D-2R A), (5) L3-L5 dynamic and L5-S1 rigid (2D-1R A), and (6) L3-S1 dynamic (3D A). Constructs 1D-2R A, 2D-1R A, and 3D A were tested again with the specialized designs of B and C of decreased stiffness. ROM, intradiscal pressure, and facet force were measured. Results: In all loading modes there was a trend of increasing motion with decreased stiffness. Significant differences were seen with more dynamic stabilization levels but no significance was seen with only decreasing the stiffness. 3R facet force at the caudal instrumented level significantly decreased compared with intact and dynamic stabilization constructs during axial rotation. Conclusion: Biomechanical testing resulted in a trend of increased ROM across instrumented levels as the stiffness was decreased. Dynamic stabilization increased the ROM across instrumented levels compared with rigid rods. These results suggest that decreasing the stiffness of the construct may lessen the probability of adjacent-level disease. Although the specialized devices are not commercially available, clinical data would be necessary for a clearer understanding of adjacent level effects and to confirm the in vitro biomechanical findings.

Original languageEnglish (US)
Pages (from-to)1913-1919
Number of pages7
JournalSpine
Volume38
Issue number22
DOIs
StatePublished - Oct 15 2013
Externally publishedYes

Fingerprint

Articular Range of Motion
Pressure
Spine
Equipment and Supplies
In Vitro Techniques

Keywords

  • 6-degree-of-freedom testing.
  • biomechanics
  • dynamic stabilization
  • facet force
  • in vitro
  • intradiscal pressure
  • lumbar
  • modifi ed stiffness
  • range of motion

ASJC Scopus subject areas

  • Clinical Neurology
  • Orthopedics and Sports Medicine

Cite this

In vitro biomechanical study to quantify range of motion, intradiscal pressure, and facet force of 3-level dynamic stabilization constructs with decreased stiffness. / Lee, Joseph K.; Gomez, Jaime A.; Michelsen, Christopher; Kim, Yongjung; Moldavsky, Mark; Chinthakunta, Suresh Reddy; Khalil, Saif.

In: Spine, Vol. 38, No. 22, 15.10.2013, p. 1913-1919.

Research output: Contribution to journalArticle

Lee, Joseph K. ; Gomez, Jaime A. ; Michelsen, Christopher ; Kim, Yongjung ; Moldavsky, Mark ; Chinthakunta, Suresh Reddy ; Khalil, Saif. / In vitro biomechanical study to quantify range of motion, intradiscal pressure, and facet force of 3-level dynamic stabilization constructs with decreased stiffness. In: Spine. 2013 ; Vol. 38, No. 22. pp. 1913-1919.
@article{0f2ec3c92cec442e952310990a929941,
title = "In vitro biomechanical study to quantify range of motion, intradiscal pressure, and facet force of 3-level dynamic stabilization constructs with decreased stiffness",
abstract = "Study Design: An in vitro biomechanical study. Objective: To perform in vitro biomechanical testing on a lumbar spine using a 6-degree-of-freedom machine. To compare the range of motion (ROM), intradiscal pressure, and facet force of different 3-level dynamic stabilization constructs with traditional rigid constructs. To determine the effect of decreasing the stiffness of the dynamic construct on the various parameters. Summary of Background Data: Dynamic stabilization systems are a surgical option that may minimize the development of adjacent segment disease. Methods: Seven T12-S1 specimens were tested at ±7.5 Nm in flexion-extension, lateral bending, and axial rotation. The testing sequence was (1) intact, (2) intact with facet sensors, (3) L3-S1 rigid (3R), (4) L3-L4 dynamic and L4-S1 rigid (1D-2R A), (5) L3-L5 dynamic and L5-S1 rigid (2D-1R A), and (6) L3-S1 dynamic (3D A). Constructs 1D-2R A, 2D-1R A, and 3D A were tested again with the specialized designs of B and C of decreased stiffness. ROM, intradiscal pressure, and facet force were measured. Results: In all loading modes there was a trend of increasing motion with decreased stiffness. Significant differences were seen with more dynamic stabilization levels but no significance was seen with only decreasing the stiffness. 3R facet force at the caudal instrumented level significantly decreased compared with intact and dynamic stabilization constructs during axial rotation. Conclusion: Biomechanical testing resulted in a trend of increased ROM across instrumented levels as the stiffness was decreased. Dynamic stabilization increased the ROM across instrumented levels compared with rigid rods. These results suggest that decreasing the stiffness of the construct may lessen the probability of adjacent-level disease. Although the specialized devices are not commercially available, clinical data would be necessary for a clearer understanding of adjacent level effects and to confirm the in vitro biomechanical findings.",
keywords = "6-degree-of-freedom testing., biomechanics, dynamic stabilization, facet force, in vitro, intradiscal pressure, lumbar, modifi ed stiffness, range of motion",
author = "Lee, {Joseph K.} and Gomez, {Jaime A.} and Christopher Michelsen and Yongjung Kim and Mark Moldavsky and Chinthakunta, {Suresh Reddy} and Saif Khalil",
year = "2013",
month = "10",
day = "15",
doi = "10.1097/BRS.0b013e3182a6a4ec",
language = "English (US)",
volume = "38",
pages = "1913--1919",
journal = "Spine",
issn = "0362-2436",
publisher = "Lippincott Williams and Wilkins",
number = "22",

}

TY - JOUR

T1 - In vitro biomechanical study to quantify range of motion, intradiscal pressure, and facet force of 3-level dynamic stabilization constructs with decreased stiffness

AU - Lee, Joseph K.

AU - Gomez, Jaime A.

AU - Michelsen, Christopher

AU - Kim, Yongjung

AU - Moldavsky, Mark

AU - Chinthakunta, Suresh Reddy

AU - Khalil, Saif

PY - 2013/10/15

Y1 - 2013/10/15

N2 - Study Design: An in vitro biomechanical study. Objective: To perform in vitro biomechanical testing on a lumbar spine using a 6-degree-of-freedom machine. To compare the range of motion (ROM), intradiscal pressure, and facet force of different 3-level dynamic stabilization constructs with traditional rigid constructs. To determine the effect of decreasing the stiffness of the dynamic construct on the various parameters. Summary of Background Data: Dynamic stabilization systems are a surgical option that may minimize the development of adjacent segment disease. Methods: Seven T12-S1 specimens were tested at ±7.5 Nm in flexion-extension, lateral bending, and axial rotation. The testing sequence was (1) intact, (2) intact with facet sensors, (3) L3-S1 rigid (3R), (4) L3-L4 dynamic and L4-S1 rigid (1D-2R A), (5) L3-L5 dynamic and L5-S1 rigid (2D-1R A), and (6) L3-S1 dynamic (3D A). Constructs 1D-2R A, 2D-1R A, and 3D A were tested again with the specialized designs of B and C of decreased stiffness. ROM, intradiscal pressure, and facet force were measured. Results: In all loading modes there was a trend of increasing motion with decreased stiffness. Significant differences were seen with more dynamic stabilization levels but no significance was seen with only decreasing the stiffness. 3R facet force at the caudal instrumented level significantly decreased compared with intact and dynamic stabilization constructs during axial rotation. Conclusion: Biomechanical testing resulted in a trend of increased ROM across instrumented levels as the stiffness was decreased. Dynamic stabilization increased the ROM across instrumented levels compared with rigid rods. These results suggest that decreasing the stiffness of the construct may lessen the probability of adjacent-level disease. Although the specialized devices are not commercially available, clinical data would be necessary for a clearer understanding of adjacent level effects and to confirm the in vitro biomechanical findings.

AB - Study Design: An in vitro biomechanical study. Objective: To perform in vitro biomechanical testing on a lumbar spine using a 6-degree-of-freedom machine. To compare the range of motion (ROM), intradiscal pressure, and facet force of different 3-level dynamic stabilization constructs with traditional rigid constructs. To determine the effect of decreasing the stiffness of the dynamic construct on the various parameters. Summary of Background Data: Dynamic stabilization systems are a surgical option that may minimize the development of adjacent segment disease. Methods: Seven T12-S1 specimens were tested at ±7.5 Nm in flexion-extension, lateral bending, and axial rotation. The testing sequence was (1) intact, (2) intact with facet sensors, (3) L3-S1 rigid (3R), (4) L3-L4 dynamic and L4-S1 rigid (1D-2R A), (5) L3-L5 dynamic and L5-S1 rigid (2D-1R A), and (6) L3-S1 dynamic (3D A). Constructs 1D-2R A, 2D-1R A, and 3D A were tested again with the specialized designs of B and C of decreased stiffness. ROM, intradiscal pressure, and facet force were measured. Results: In all loading modes there was a trend of increasing motion with decreased stiffness. Significant differences were seen with more dynamic stabilization levels but no significance was seen with only decreasing the stiffness. 3R facet force at the caudal instrumented level significantly decreased compared with intact and dynamic stabilization constructs during axial rotation. Conclusion: Biomechanical testing resulted in a trend of increased ROM across instrumented levels as the stiffness was decreased. Dynamic stabilization increased the ROM across instrumented levels compared with rigid rods. These results suggest that decreasing the stiffness of the construct may lessen the probability of adjacent-level disease. Although the specialized devices are not commercially available, clinical data would be necessary for a clearer understanding of adjacent level effects and to confirm the in vitro biomechanical findings.

KW - 6-degree-of-freedom testing.

KW - biomechanics

KW - dynamic stabilization

KW - facet force

KW - in vitro

KW - intradiscal pressure

KW - lumbar

KW - modifi ed stiffness

KW - range of motion

UR - http://www.scopus.com/inward/record.url?scp=84886095469&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84886095469&partnerID=8YFLogxK

U2 - 10.1097/BRS.0b013e3182a6a4ec

DO - 10.1097/BRS.0b013e3182a6a4ec

M3 - Article

C2 - 23921330

AN - SCOPUS:84886095469

VL - 38

SP - 1913

EP - 1919

JO - Spine

JF - Spine

SN - 0362-2436

IS - 22

ER -