The magnitude of angular and translational displacement of dens fractures is dependent on the sagittal alignment of the cervical spine rather than the force of injury

Sabina R. Blizzard, Bala Krishnamoorthy, Matthew Shinseki, Marcel Betsch, Jung Yoo

Research output: Contribution to journalArticle

Abstract

Background Context: Although it is generally believed that the magnitude of dens fracture displacement is proportional to the amount of force applied to the cervical spine during injury, the factors responsible for displacement have not been studied. Purpose: Our aim was to determine factors that contribute to horizontal and angular displacement of dens fractures. Study Design/Setting: We conducted a retrospective review of adult patients who were admitted to our level 1 trauma center between January 1, 2008 and December 31, 2013. Patient Sample: Angular and horizontal displacements of the fractured dens in 57 patients were measured. Subjects were grouped based on mechanism of fracture: motor vehicle accident, ground level fall, and higher falls. Outcome Measures: Cervical lordosis was measured between C2 and T1. C3-C4, C4-C5, C5-C6, and C6-C7 disc inclination angles were measured. Anteroposterior sagittal balance was assessed by comparing the sagittal position of the C2 body with the C7 body. Methods: Data were analyzed using Pearson correlations, independent t tests, and support vector regression to construct predictive models that determine factors contributing to the angular and horizontal displacements. Results: The mean horizontal displacement of the fractured dens was not significantly different among groups. However, the dens in those with ground level falls had a significantly greater mean fracture angle compared with the higher energy trauma groups (p = 01). There were positive correlations between angular displacement and C5-C6 disc space inclination angle (r=0.67, p<.01) and C6-C7 disc space inclination angle (r=0.61, p<.01). There were positive correlations between horizontal displacement and C6-C7 inclination angle (r=0.40, p<.01) and sagittal alignment (r=0.32, p<.01). The predictive model using all variables demonstrated that angular fracture displacement was only dependent on C5-C6 disc space inclination angle. Horizontal displacement was only dependent on C6-C7 inclination angle and anteroposterior sagittal balance. Conclusions: Disc space inclination angles of the lower cervical spine and the cervical sagittal balance most contribute to the magnitude of angular and horizontal displacement of the dens after fracture.

Original languageEnglish (US)
JournalSpine Journal
DOIs
StateAccepted/In press - 2017

Fingerprint

Spine
Wounds and Injuries
Lordosis
Trauma Centers
Motor Vehicles
Accidents
Outcome Assessment (Health Care)

Keywords

  • Angular displacement
  • Cervical spine
  • Dens fracture
  • Fracture displacement
  • Horizontal displacement
  • Odontoid fracture
  • Trauma

ASJC Scopus subject areas

  • Surgery
  • Clinical Neurology

Cite this

The magnitude of angular and translational displacement of dens fractures is dependent on the sagittal alignment of the cervical spine rather than the force of injury. / Blizzard, Sabina R.; Krishnamoorthy, Bala; Shinseki, Matthew; Betsch, Marcel; Yoo, Jung.

In: Spine Journal, 2017.

Research output: Contribution to journalArticle

@article{68251de617614394ae4f5a9566565968,
title = "The magnitude of angular and translational displacement of dens fractures is dependent on the sagittal alignment of the cervical spine rather than the force of injury",
abstract = "Background Context: Although it is generally believed that the magnitude of dens fracture displacement is proportional to the amount of force applied to the cervical spine during injury, the factors responsible for displacement have not been studied. Purpose: Our aim was to determine factors that contribute to horizontal and angular displacement of dens fractures. Study Design/Setting: We conducted a retrospective review of adult patients who were admitted to our level 1 trauma center between January 1, 2008 and December 31, 2013. Patient Sample: Angular and horizontal displacements of the fractured dens in 57 patients were measured. Subjects were grouped based on mechanism of fracture: motor vehicle accident, ground level fall, and higher falls. Outcome Measures: Cervical lordosis was measured between C2 and T1. C3-C4, C4-C5, C5-C6, and C6-C7 disc inclination angles were measured. Anteroposterior sagittal balance was assessed by comparing the sagittal position of the C2 body with the C7 body. Methods: Data were analyzed using Pearson correlations, independent t tests, and support vector regression to construct predictive models that determine factors contributing to the angular and horizontal displacements. Results: The mean horizontal displacement of the fractured dens was not significantly different among groups. However, the dens in those with ground level falls had a significantly greater mean fracture angle compared with the higher energy trauma groups (p = 01). There were positive correlations between angular displacement and C5-C6 disc space inclination angle (r=0.67, p<.01) and C6-C7 disc space inclination angle (r=0.61, p<.01). There were positive correlations between horizontal displacement and C6-C7 inclination angle (r=0.40, p<.01) and sagittal alignment (r=0.32, p<.01). The predictive model using all variables demonstrated that angular fracture displacement was only dependent on C5-C6 disc space inclination angle. Horizontal displacement was only dependent on C6-C7 inclination angle and anteroposterior sagittal balance. Conclusions: Disc space inclination angles of the lower cervical spine and the cervical sagittal balance most contribute to the magnitude of angular and horizontal displacement of the dens after fracture.",
keywords = "Angular displacement, Cervical spine, Dens fracture, Fracture displacement, Horizontal displacement, Odontoid fracture, Trauma",
author = "Blizzard, {Sabina R.} and Bala Krishnamoorthy and Matthew Shinseki and Marcel Betsch and Jung Yoo",
year = "2017",
doi = "10.1016/j.spinee.2017.06.021",
language = "English (US)",
journal = "Spine Journal",
issn = "1529-9430",
publisher = "Elsevier Inc.",

}

TY - JOUR

T1 - The magnitude of angular and translational displacement of dens fractures is dependent on the sagittal alignment of the cervical spine rather than the force of injury

AU - Blizzard, Sabina R.

AU - Krishnamoorthy, Bala

AU - Shinseki, Matthew

AU - Betsch, Marcel

AU - Yoo, Jung

PY - 2017

Y1 - 2017

N2 - Background Context: Although it is generally believed that the magnitude of dens fracture displacement is proportional to the amount of force applied to the cervical spine during injury, the factors responsible for displacement have not been studied. Purpose: Our aim was to determine factors that contribute to horizontal and angular displacement of dens fractures. Study Design/Setting: We conducted a retrospective review of adult patients who were admitted to our level 1 trauma center between January 1, 2008 and December 31, 2013. Patient Sample: Angular and horizontal displacements of the fractured dens in 57 patients were measured. Subjects were grouped based on mechanism of fracture: motor vehicle accident, ground level fall, and higher falls. Outcome Measures: Cervical lordosis was measured between C2 and T1. C3-C4, C4-C5, C5-C6, and C6-C7 disc inclination angles were measured. Anteroposterior sagittal balance was assessed by comparing the sagittal position of the C2 body with the C7 body. Methods: Data were analyzed using Pearson correlations, independent t tests, and support vector regression to construct predictive models that determine factors contributing to the angular and horizontal displacements. Results: The mean horizontal displacement of the fractured dens was not significantly different among groups. However, the dens in those with ground level falls had a significantly greater mean fracture angle compared with the higher energy trauma groups (p = 01). There were positive correlations between angular displacement and C5-C6 disc space inclination angle (r=0.67, p<.01) and C6-C7 disc space inclination angle (r=0.61, p<.01). There were positive correlations between horizontal displacement and C6-C7 inclination angle (r=0.40, p<.01) and sagittal alignment (r=0.32, p<.01). The predictive model using all variables demonstrated that angular fracture displacement was only dependent on C5-C6 disc space inclination angle. Horizontal displacement was only dependent on C6-C7 inclination angle and anteroposterior sagittal balance. Conclusions: Disc space inclination angles of the lower cervical spine and the cervical sagittal balance most contribute to the magnitude of angular and horizontal displacement of the dens after fracture.

AB - Background Context: Although it is generally believed that the magnitude of dens fracture displacement is proportional to the amount of force applied to the cervical spine during injury, the factors responsible for displacement have not been studied. Purpose: Our aim was to determine factors that contribute to horizontal and angular displacement of dens fractures. Study Design/Setting: We conducted a retrospective review of adult patients who were admitted to our level 1 trauma center between January 1, 2008 and December 31, 2013. Patient Sample: Angular and horizontal displacements of the fractured dens in 57 patients were measured. Subjects were grouped based on mechanism of fracture: motor vehicle accident, ground level fall, and higher falls. Outcome Measures: Cervical lordosis was measured between C2 and T1. C3-C4, C4-C5, C5-C6, and C6-C7 disc inclination angles were measured. Anteroposterior sagittal balance was assessed by comparing the sagittal position of the C2 body with the C7 body. Methods: Data were analyzed using Pearson correlations, independent t tests, and support vector regression to construct predictive models that determine factors contributing to the angular and horizontal displacements. Results: The mean horizontal displacement of the fractured dens was not significantly different among groups. However, the dens in those with ground level falls had a significantly greater mean fracture angle compared with the higher energy trauma groups (p = 01). There were positive correlations between angular displacement and C5-C6 disc space inclination angle (r=0.67, p<.01) and C6-C7 disc space inclination angle (r=0.61, p<.01). There were positive correlations between horizontal displacement and C6-C7 inclination angle (r=0.40, p<.01) and sagittal alignment (r=0.32, p<.01). The predictive model using all variables demonstrated that angular fracture displacement was only dependent on C5-C6 disc space inclination angle. Horizontal displacement was only dependent on C6-C7 inclination angle and anteroposterior sagittal balance. Conclusions: Disc space inclination angles of the lower cervical spine and the cervical sagittal balance most contribute to the magnitude of angular and horizontal displacement of the dens after fracture.

KW - Angular displacement

KW - Cervical spine

KW - Dens fracture

KW - Fracture displacement

KW - Horizontal displacement

KW - Odontoid fracture

KW - Trauma

UR - http://www.scopus.com/inward/record.url?scp=85026298816&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85026298816&partnerID=8YFLogxK

U2 - 10.1016/j.spinee.2017.06.021

DO - 10.1016/j.spinee.2017.06.021

M3 - Article

C2 - 28694217

AN - SCOPUS:85026298816

JO - Spine Journal

JF - Spine Journal

SN - 1529-9430

ER -