title: [Finite element analysis of the initial stability of subtalar arthrodesis with double-screw fixation].
abstract: OBJECTIVE
  To assess the optimal configuration of double-screw fixation for subtalar arthrodesis using finite element analysis.
  
  
  METHODS
  Three-dimensional finite element double-screw models of subtalar arthrodesis were reconstructed using Mimics 13.0, Geomagic 10.0 and solid works software based on the 3-D images of the volunteer's right foot. The external and internal rotation torques of 4 N·m were applied, and the micromotion at the bone-to-bone interface were measured to evaluate the initial stability of subtalar arthrodesis.
  
  
  RESULTS
  A neck screw plus an anterolateral dome screw was the most stable model. The peak micromotion at the fusion site of this fixation configuration were 41.67mnplus;0.49 and 42.64mnplus;0.75 µm in response to the respectively. A neck screw plus a posteromedial dome screw was the least stable model, with peak micromotion at the bone-to-bone interface of 61.76mnplus;1.00 and 62.32mnplus;0.90 µm, respectively.
  
  
  CONCLUSIONS
  A neck screw plus an anterolateral dome screw is the best fixation configuration while a neck screw plus a posteromedial screw provides the least stability of subtalar arthrodesis. Three-dimensional finite element models allow effective preoperative planning of the screw number and placement.
authors.affiliation: Department of Orthopedics and Trauma, Southern Medical University, Guangzhou, China. cuizhuang3816@163.com
authors.forename: Zhuang
authors.initials: Z
authors.lastname: Cui
authors.forename: Bin
authors.initials: B
authors.lastname: Yu
authors.forename: Xue
authors.initials: X
authors.lastname: Li
authors.forename: Changpeng
authors.initials: C
authors.lastname: Xu
authors.forename: Jinqi
authors.initials: J
authors.lastname: Song
authors.forename: Hanbin
authors.initials: H
authors.lastname: Ouyang
authors.forename: Xicai
authors.initials: X
authors.lastname: Diao
authors.forename: Liguang
authors.initials: L
authors.lastname: Chen
mesh_terms: D000328:Adult; D000842:Ankle / Q000000981:diagnostic imaging; D001174:Arthrodesis / Q000379:methods*; D001863:Bone Screws; D020342:Finite Element Analysis; D006801:Humans; D021621:Imaging, Three-Dimensional; D016268:Internal Fixators; D008953:Models, Anatomic; D012984:Software; D013380:Subtalar Joint / Q000601:surgery; D014057:Tomography, X-Ray Computed