Acute Failure Characteristics of Six Methods for Internal Fixation of Canine Femoral Oblique Fractures

R. Nye; E. Egger; J. Huhta; M. Histand; C. Mallinckrodt

doi:10.1055/s-0038-1632513

Veterinary and Comparative Orthopaedics and Traumatology, Table of Contents

Vet Comp Orthop Traumatol 1996; 09(03): 106-10
DOI: 10.1055/s-0038-1632513

Original Research

Schattauer GmbH

Acute Failure Characteristics of Six Methods for Internal Fixation of Canine Femoral Oblique Fractures

R. Nye

¹From the Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, Colorado, USA

,

E. Egger

¹From the Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, Colorado, USA

,

J. Huhta

²Department of Engineering, Fort Collins, Colorado, USA

,

M. Histand

²Department of Engineering, Fort Collins, Colorado, USA

,

C. Mallinckrodt

³Department of Statistics, Colorado State University, Fort Collins, Colorado, USA

› Author Affiliations

Abstract

Summary

A long oblique osteotomy model of canine femoral fractures was created to compare six methods of internal fixation. The following methods were tested: three cerclage wires, three lag screws, eight-hole dynamic compression plate attached with six cerclage wires, eight-hole dynamic compression plate attached with six cortical screws, eight-hole dynamic compression plate attached with six cortical screws superimposed over three cerclage wires, and an eight-hole dynamic compression plate attached with six cortical screws superimposed over three lag screws. The repaired femurs were mounted in a mechanical testing machine in an orientation designed to mimic physiological loading. Axial compression was applied which resulted in the test specimens experiencing simultaneous compressive and bending forces. The effects of the method of osteotomy repair, bone temperature, and bone diameter were analyzed. The maximum load and the stiffness of the composite fixation and bones were determined. There were not any statistically significant differences in stiffness among the groups. All fixation methods, in which plates were attached with screws, resulted in significantly greater maximum load values than treatment techniques where plates were not used. None of the fixation methods attained a mean maximum load greater than 58% of the mean maximum load of the control femurs.

Six methods of commonly used internal fixation methods are compared. A method of in vitro positioning of test femurs to mimic in vivo orientation is presented. Maximum load capabilities of fixation do not significantly increase with the addition of interfragmentary compression to plate fixation.

Keywords

Internal fixation - test positioning - oblique osteotomy - maximum load

Full Text

References

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