Improved Healing of Large, Osseous, Segmental Defects by Reverse Dynamization: Evaluation in a Sheep Model

Abstract

Mechanical testing of the finalized fixator design was completed during course of current project year. Using cadaveric sheep tibiae it was found that when the fixator was modulated from low to high stiffness, the stiffness doubled, which is sufficiently close to desired increment of 2.5-fold to justify the in vivo studies on living sheep. To confirm that the fixator could bear the forces imposed by adult, ambulating sheep, aplastic yield point above 500Nwas determined. Moreover, negligible inter-fragmentary movement differences of the fracture gap occurred during repeated load-cycling to mimic the projected lifecycle of the fixator while attached to the sheep. This information has been coupled with a finite element analysis model of the mechanical stress properties of the fixator. This completes SOW tasks 1-3. Finalization of surgical procedure (through mock surgeries) and animal husbandry protocols have been completed. This will allow a seamless transition into the live animal surgeries (SOW task 4).

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Document Details

Document Type
Technical Report
Publication Date
Oct 01, 2015
Accession Number
AD1008489

Entities

People

  • Christopher H. Evans
  • Nicholas P. Quirk

Tags

DTIC Thesaurus Topics

  • Animal Husbandry
  • Biomedical Research
  • Elements
  • Extensometers
  • Finite Element Analysis
  • Manufacturing
  • Mechanical Properties
  • Mechanics
  • Osteogenesis
  • Peptide Growth Factors
  • Plastic Deformation
  • Stiffness
  • Stresses
  • Surgery
  • Tensile Strength
  • Test And Evaluation
  • Yield Strength

Readers

  • Clinical Trial Research.
  • Structural Dynamics.
  • Trauma Surgery or Emergency Medicine.