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.
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.
Halling
Krista B
KB
Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
Lewis
Daniel D
DD
Cross
Alan R
AR
Sammy
Richard J
RJ
Rapoff
Andrew J
AJ
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*