title: Biomechanical comparison of transforaminal lumbar interbody fusion with 1 or 2 cages by finite-element analysis.
abstract: BACKGROUND
  Anterior lumbar interbody fusion and posterior lumbar interbody fusion with 1 cage have been shown to have similar biomechanics compared with the use of 2 cages. However, there have been no reports on the biomechanical differences between using 1 or 2 cages in transforaminal lumbar interbody fusion (TLIF) surgery.
  
  
  OBJECTIVE
  To determine the biomechanical differences between the use of 1 or 2 cages in TLIF by finite-element analysis.
  
  
  METHODS
  Three validated finite-element models of the L3-L5 lumbar segment were created (intact model and single- and paired-cage TLIF models). To study the biomechanics, a compressive preload of 400 N over 7.5 N-m was applied to the superior surfaces of the L3 vertebral body to simulate flexion, extension, rotation, and lateral bending.
  
  
  RESULTS
  There was no significant difference in the range of motion between single-cage and paired-cage TLIF models, < 1° for all loading cases. Cage stress was high in the single-cage TLIF model under all loading conditions. Bone graft stress was high in the single-cage TLIF model. Pedicle screw stress was higher in the single-cage compared with the paired-cage TLIF.
  
  
  CONCLUSIONS
  Single-cage TLIF approximates biomechanical stability and increases the stress of the bone graft. The use of a single cage may simplify the standard TLIF procedure, shorten operative times, decrease cost, and provide satisfactory clinical outcomes. Thus, single-cage TLIF is a useful alternative to traditional 2-cage TLIF.
authors: Department of Orthopaedics, the First Hospital of Wujiang, Jiangsu Province, People's Republic of China.
authors: Hao
authors: H
authors: Xu
authors: Wen
authors: W
authors: Ju
authors: Neng
authors: N
authors: Xu
authors: Xiaojian
authors: X
authors: Zhang
authors: Xiaodong
authors: X
authors: Zhu
authors: Lifan
authors: L
authors: Zhu
authors: Xuefeng
authors: X
authors: Qian
authors: Fengbiao
authors: F
authors: Wen
authors: Weidong
authors: W
authors: Wu
authors: Fugui
authors: F
authors: Jiang
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D003198:Computer Simulation; D020342:Finite Element Analysis; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000502:physiology* / Q000601:surgery; D008297:Male; D008953:Models, Anatomic; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology*; D015203:Reproducibility of Results; D013123:Spinal Fusion / Q000379:methods*; D015898:Tomography Scanners, X-Ray Computed