title: Single column locking plate fixation is inadequate in two column acetabular fractures. A biomechanical analysis.
abstract: BACKGROUND
  The objective of this study was to determine whether one can achieve stable fixation of a two column (transverse) acetabular fracture by only fixing a single column with a locking plate and unicortical locking screws. We hypothesized that a locking plate applied to the anterior column of a transverse acetabular fracture would create a construct that is more rigid than a non-locking plate, and that this construct would be biomechanically comparable to two column fixation.
  
  
  METHODS
  Using urethane foam models of the pelvis, we simulated transverse acetabular fractures and stabilized them with 1) an anterior column plate with bicortical screws, 2) an anterior locking plate with unicortical screws, 3) an anterior plate and posterior column lag screw, and 4) a posterior plate with an anterior column lag screw. These constructs were mechanically loaded on a servohydraulic material testing machine. Construct stiffness and fracture displacement were measured.
  
  
  CONCLUSIONS
  We found that two column fixation is 54% stiffer than a single column fixation with a conventional plate with bicortical screws. There was no significant difference between fixation with an anterior column locking plate with unicortical screws and an anterior plate with posterior column lag screw. We detected a non-significant trend towards more stiffness for the anterior locking plate compared to the anterior non-locking plate.
  
  
  CONCLUSIONS
  In conclusion, a locking plate construct of the anterior column provides less stability than a traditional both column construct with posterior plate and anterior column lag screw. However, the locking construct offers greater strength than a non-locking, bicortical construct, which in addition often requires extensive contouring and its application is oftentimes accompanied by the risk of neurovascular damage.
authors.affiliation: Department of Orthopaedic Surgery, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA. pleucht@stanford.edu.
authors.forename: Kiarash
authors.initials: K
authors.lastname: Khajavi
authors.forename: Arthur T
authors.initials: AT
authors.lastname: Lee
authors.forename: Derek P
authors.initials: DP
authors.lastname: Lindsey
authors.forename: Philipp
authors.initials: P
authors.lastname: Leucht
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Bellino
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Giori
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