title: Effects of cervical arthrodesis and arthroplasty on neck response during a simulated frontal automobile collision.
abstract: BACKGROUND
  Whereas arthrodesis is the most common surgical intervention for the treatment of symptomatic cervical degenerative disc disease, arthroplasty has become increasingly more popular over the past decade. Although literature exists comparing the effects of anterior cervical discectomy and fusion and cervical total disc replacement (CTDR) on neck kinematics and loading, the vast majority of these studies apply only quasi-static, noninjurious loading conditions to a segment of the cervical spine.
  
  
  OBJECTIVE
  The objective of this study was to investigate the effects of arthrodesis and arthroplasty on biomechanical neck response during a simulated frontal automobile collision with air bag deployment.
  
  
  METHODS
  This study used a full-body, 50th percentile seated male finite element (FE) model to evaluate neck response during a dynamic impact event. The cervical spine was modified to simulate either an arthrodesis or arthroplasty procedure at C5-C6.
  
  
  METHODS
  Five simulations of a belted driver, subjected to a 13.3 m/s ΔV frontal impact with air bag deployment, were run in LS-DYNA with the Global Human Body Models Consortium full-body FE model. The first simulation used the original model, with no modifications to the neck, whereas the remaining four were modified to represent either interbody arthrodesis or arthroplasty of C5-C6. Cross-sectional forces and moments at the C5 and C6 cervical levels of the neck, along with interbody and facet forces between C5 and C6, were reported.
  
  
  RESULTS
  Adjacent-level, cross-sectional neck loading was maintained in all simulations without exceeding any established injury thresholds. Interbody compression was greatest for the CTDRs, and interbody tension occurred only in the fused and nonmodified spines. Some interbody separation occurred between the superior and inferior components of the CTDRs during flexion-induced tension of the cervical spine, increasing the facet loads.
  
  
  CONCLUSIONS
  This study evaluated the effects of C5-C6 cervical arthrodesis and arthroplasty on neck response during a simulated frontal automobile impact. Although cervical arthrodesis and arthroplasty at C5-C6 did not appear to significantly alter the adjacent-level, cross-sectional neck responses during a simulated frontal automobile impact, key differences were noted in the interbody and facet loading.
authors.affiliation: Center for Injury Biomechanics, Virginia Tech-Wake Forest University, 575 N. Patterson Ave., Suite 120, Winston-Salem, NC 27157, USA.
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: White
authors.affiliation: Center for Injury Biomechanics, Virginia Tech-Wake Forest University, 575 N. Patterson Ave., Suite 120, Winston-Salem, NC 27157, USA.
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Moreno
authors.affiliation: Center for Injury Biomechanics, Virginia Tech-Wake Forest University, 575 N. Patterson Ave., Suite 120, Winston-Salem, NC 27157, USA.
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Brown
authors.affiliation: Center for Injury Biomechanics, Virginia Tech-Wake Forest University, 575 N. Patterson Ave., Suite 120, Winston-Salem, NC 27157, USA.
authors.forename: F Scott
authors.initials: FS
authors.lastname: Gayzik
authors.affiliation: Department of Neurosurgery, Wake Forest University School of Medicine, Medical Center Blvd., Winston-Salem, NC 27157, USA.
authors.forename: Wesley
authors.initials: W
authors.lastname: Hsu
authors.affiliation: Department of Neurosurgery, Wake Forest University School of Medicine, Medical Center Blvd., Winston-Salem, NC 27157, USA.
authors.forename: Alexander K
authors.initials: AK
authors.lastname: Powers
authors.affiliation: Center for Injury Biomechanics, Virginia Tech-Wake Forest University, 575 N. Patterson Ave., Suite 120, Winston-Salem, NC 27157, USA. Electronic address: jdstitzel@gmail.com.
authors.forename: Joel D
authors.initials: JD
authors.lastname: Stitzel
mesh_terms: D000063:Accidents, Traffic; D017278:Air Bags; D001178:Arthroplasty; D001336:Automobiles; D001696:Biomechanical Phenomena; D002574:Cervical Vertebrae / Q000601:surgery*; D003430:Cross-Sectional Studies; D017586:Diskectomy; D006801:Humans; D008297:Male; D008348:Manikins; D009333:Neck; D016059:Range of Motion, Articular; D013122:Spinal Diseases / Q000601:surgery*; D013123:Spinal Fusion; D059145:Total Disc Replacement
keywords: Arthrodesis; Arthroplasty; Finite element analysis; GHBMC; Prestige ST; ProDisc-c