title: Biomechanical comparison of posterior lumbar interbody fusion and transforaminal lumbar interbody fusion by finite element analysis.
abstract: BACKGROUND
  The transforaminal lumbar interbody fusion (TLIF) procedure may reduce many of the risks and limitations associated with posterior lumbar interbody fusion (PLIF). However, little is known about the biomechanical difference between PLIF and TLIF.
  
  
  OBJECTIVE
  To determine the biomechanical difference between PLIF and TLIF by finite-element analysis.
  
  
  METHODS
  Three validated finite-element models of L3-5 lumbar segment were created (intact model, PLIF model, and TLIF model). To analyze the biomechanics of these models, flexion, extension, rotation, and lateral bending moments of 7.5 N-m with a compressive preload of 400 N were imposed on the superior surfaces of the L3 vertebral body.
  
  
  RESULTS
  The range of motion at the L4-5 level of the PLIF and TLIF models decreased for all loading cases, compared with the intact model. Differences in the range of motion between PLIF and TLIF were not significant at less than 1 degree for all loading cases. The stress of the cage was found to be high in the PLIF model at the cage-endplate interface under all loading conditions. The stress exerted on the pedicle screw was greater in TLIF than PLIF. Particularly in flexion loading, the stress experienced by the pedicle screw in the TLIF model was 70.7% greater than that in the PLIF model.
  
  
  CONCLUSIONS
  The TLIF procedure increases the approximate biomechanical stability and reduces stress at the cage-endplate interface, except for a slight increase in screw stress. Clinically, the TLIF procedure may reduce many of the risks and limitations associated with PLIF and offer a useful alternative to the PLIF procedure.
authors.affiliation: Department of Orthopaedics, First Hospital of Wujiang, Jiangsu Province, People's Republic of China. xuhaomouse2004@sina.com
authors.forename: Hao
authors.initials: H
authors.lastname: Xu
authors.forename: Hao
authors.initials: H
authors.lastname: Tang
authors.forename: Xuemei
authors.initials: X
authors.lastname: Guan
authors.forename: Fugui
authors.initials: F
authors.lastname: Jiang
authors.forename: Neng
authors.initials: N
authors.lastname: Xu
authors.forename: Wen
authors.initials: W
authors.lastname: Ju
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhu
authors.forename: Xiaojian
authors.initials: X
authors.lastname: Zhang
authors.forename: Qiulin
authors.initials: Q
authors.lastname: Zhang
authors.forename: Ming
authors.initials: M
authors.lastname: Li
mesh_terms: D001696:Biomechanical Phenomena; D020342:Finite Element Analysis; D006801:Humans; D016059:Range of Motion, Articular / Q000502:physiology; D013123:Spinal Fusion / Q000379:methods*