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Vet Comp Orthop Traumatol 2013; 26(03): 172-176
DOI: 10.3415/VCOT-12-03-0047
Original Research
Schattauer GmbH

Comparison of the axial stiffness of carbon composite and aluminium alloy circular external skeletal fixator rings

C. M. Gauthier
1   College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
,
M. P. Kowaleski
2   Department of Clinical Sciences, Cummings School of Veterinary Medicine, Tufts University, North Grafton, Massachusetts, USA
,
P. D. Gerard
3   Department of Mathematical Sciences, Clemson University, Clemson, South Carolina, USA
,
G. L. Rovesti
1   College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
› Author Affiliations
Further Information

Publication History

Received 29 March 2012

Accepted 23 April 2012

Publication Date:
19 December 2017 (online)

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Summary

Objectives: The purpose of this study was to compare the axial stiffness of aluminium alloy and carbon composite single-ring constructs.

Methods: Single-ring constructs were made with rings of different material compositions (aluminium alloy and carbon composite), diameters (55 mm, 85 mm, and 115 mm), and thicknesses (6 mm for the single-ring, 12 mm for the double-ring) with all other components remaining constant. Stiffness of each construct was determined under loading in axial compression with a materials testing machine. The axial stiffness of each group was compared using a three-factor factorial analysis of variance investigating all main effects and interactions between ring diameter, ring thickness, and ring material composition; p <0.05 was considered significant.

Results: Carbon composite constructs were 16-55% as stiff as corresponding aluminium alloy constructs. Within each combination of ring material composition and ring diameter, stiffness did not significantly increase when the ring thickness was doubled. Within each combination of ring material composition and ring thickness, stiffness significantly decreased with increased ring diameter.

Clinical significance: Aluminium alloy rings were found to be significantly stiffer than carbon composite rings. Although the carbon composite rings were considerably less stiff, clinical recommendations cannot be made from a single-ring in vitro analysis. Further studies are needed to evaluate the behaviour of these rings in vivo.

Keywords

biomechanics - circular external skeletal fixator - axial - compression
 

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