title: Biomechanical comparison of fixation systems in posterior wall fracture of acetabular by finite element analysis.
abstract: BACKGROUND
  The use of reconstruction plates and lag screws has been recommended for fractures to the posterior wall of the acetabulum. However, little information about the rigidity of recommended forms of fracture fixation is available. This study aimed to evaluate the biomechanical difference among the fixation systems.
  
  
  METHODS
  A posterior wall fracture, which is represented by softer elements with lower elastic modulus, was created along an arc of 40-90° about the acetabular rim. Three different fixation systems: screws alone, reconstruction plate with screws, reconstruction plate with T-shaped plates were used to fix the posterior wall fractures to the acetabulum.
  
  
  RESULTS
  All three fixation system can be used to obtain good functional outcomes. The reconstruction plate with T-shaped plates was beneficial to increasing the effective stiffness, decreasing the stress concentration and enhancing the rigidity of fracture fixation. So this fixation system served an ideal result in the analysis.
  
  
  CONCLUSIONS
  Theoretically, the reconstruction plate with T-shaped plates system may reduce many of the risks and limitations compared to the other fixation systems. This fixation system may result in a clinical benefit.
authors.affiliation: a College of Mechanics , Taiyuan University of Technology , Taiyuan , China.
authors.forename: Jianyin
authors.initials: J
authors.lastname: Lei
authors.affiliation: a College of Mechanics , Taiyuan University of Technology , Taiyuan , China.
authors.forename: Haibo
authors.initials: H
authors.lastname: Liu
authors.affiliation: a College of Mechanics , Taiyuan University of Technology , Taiyuan , China.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Li
authors.affiliation: a College of Mechanics , Taiyuan University of Technology , Taiyuan , China.
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Wang
authors.affiliation: b Department of Orthopedics , Wuhan General Hospital of Guangzhou Command , Wuhan , China.
authors.forename: Ximing
authors.initials: X
authors.lastname: Liu
authors.affiliation: a College of Mechanics , Taiyuan University of Technology , Taiyuan , China.
authors.forename: Longmao
authors.initials: L
authors.lastname: Zhao
mesh_terms: D000077:Acetabulum / Q000293:injuries*; D001860:Bone Plates; D001863:Bone Screws; D020342:Finite Element Analysis; D005593:Fracture Fixation, Internal / Q000295:instrumentation*; D050723:Fractures, Bone / Q000601:surgery*; D006801:Humans; D016059:Range of Motion, Articular; D013718:Tensile Strength; D016474:Weight-Bearing
keywords: Posterior wall fracture; acetabulum; finite element analysis; fixation systems