title: Biomechanical comparison of a circular external skeletal fixator construct to pin and tension band wire fixation for the stabilization of olecranon osteotomies in dogs: a cadaveric study.
abstract: OBJECTIVE
  To compare anatomic reduction and the biomechanical properties of a circular external skeletal fixator (CESF) construct to pin and tension band wire (PTBW) fixation for the stabilization of olecranon osteotomies in dogs.
  
  
  METHODS
  Cadaveric study.
  
  
  METHODS
  Forelimbs from 12 skeletally mature mixed-breed dogs, weighing 23 to 28 kg.
  
  
  METHODS
  An olecranon osteotomy was stabilized with either a CESF construct or PTBW fixation. A single distractive load to failure was applied to each specimen through the triceps tendon. Osteotomy reduction and biomechanical properties were compared between fixation groups.
  
  
  RESULTS
  Reduction was not significantly different (gap: P =.171; malalignment: P =.558) between fixation groups. Osteotomies stabilized with the CESF had greater stiffness (P <.0001) and maximum load sustained (P <.0001) compared to PTBW fixation. There was no significant difference for yield load (P =.318) or for load at 1 mm of axial displacement (P =.997) between fixation groups. Failure of fixation occurred by bending of the intramedullary Steinmann pin and the fixation wires in the CESF specimens and by untwisting of the tension band wire knot with pullout and bending of the Kirschner wires in the PTBW specimens.
  
  
  CONCLUSIONS
  Specimens stabilized with the CESF construct had similar reduction and yield load, greater stiffness and maximum load sustained, and less elastic deformation than specimens stabilized with PTBW fixation.
  
  
  CONCLUSIONS
  The CESF construct may provide a biomechanically favorable alternative to PTBW fixation for stabilization of olecranon osteotomies in dogs, and its application warrants clinical investigation.
authors.affiliation: Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
authors.forename: Krista B
authors.initials: KB
authors.lastname: Halling
authors.forename: Daniel D
authors.initials: DD
authors.lastname: Lewis
authors.forename: Alan R
authors.initials: AR
authors.lastname: Cross
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Sammy
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Rapoff
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D001858:Bone Nails / Q000662:veterinary; D001864:Bone Wires / Q000662:veterinary; D002102:Cadaver; D004285:Dogs / Q000293:injuries*; D016267:External Fixators / Q000662:veterinary*; D005592:Fracture Fixation / Q000295:instrumentation / Q000662:veterinary*; D006810:Humeral Fractures / Q000601:surgery / Q000662:veterinary*; D010027:Osteotomy / Q000295:instrumentation / Q000379:methods / Q000662:veterinary*