title: Biomechanical comparison of different stabilization constructs for unstable posterior wall fractures of acetabulum. A cadaveric study.
abstract: OBJECTIVE
  Operative treatment of unstable posterior wall fractures of acetabulum has been widely recommended. This laboratory study was undertaken to evaluate static fixation strength of three common fixation constructs: interfragmentary screws alone, in combination with conventional reconstruction plate, or locking reconstruction plate.
  
  
  METHODS
  Six formalin-preserved cadaveric pelvises were used for this investigation. A posterior wall fracture was created along an arc of 40-90 degree about the acetabular rim. Three groups of different fixation constructs (two interfragmentary screws alone; two interfragmentary screws and a conventional reconstruction plate; two interfragmentary screws and a locking reconstruction) were compared. Pelvises were axial loaded with six cycles of 1500 N. Dislocation of superior and inferior fracture site was analysed with a multidirectional ultrasonic measuring system.
  
  
  RESULTS
  No statistically significant difference was found at each of the superior and inferior fracture sites between the three types of fixation. In each group, the vector dislocation at superior fracture site was significantly larger than inferior one.
  
  
  CONCLUSIONS
  All those three described fixation constructs can provide sufficient stability for posterior acetabular fractures and allow early mobilization under experimental conditions. Higher posterior acetabular fracture line, transecting the weight-bearing surface, may indicate a substantial increase in instability, and need more stable pattern of fixation.
authors.affiliation: Department of Orthopaedics, Changhai Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Yuntong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Orthopaedics, Changhai Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Tang
authors.affiliation: Department of Orthopaedics, Changhai Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Panfeng
authors.initials: P
authors.lastname: Wang
authors.affiliation: Department of Orthopaedics, Changhai Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Xue
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Department of Orthopaedics, Changhai Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Shuogui
authors.initials: S
authors.lastname: Xu
authors.affiliation: Department of Orthopaedics, Changhai Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Chuncai
authors.initials: C
authors.lastname: Zhang
mesh_terms: D000077:Acetabulum / Q000293:injuries* / Q000503:physiopathology / Q000601:surgery*; D000368:Aged; D001696:Biomechanical Phenomena; D001860:Bone Plates; D001863:Bone Screws; D002102:Cadaver; D005593:Fracture Fixation, Internal / Q000295:instrumentation / Q000379:methods*; D050723:Fractures, Bone / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016474:Weight-Bearing