Download PDF
Vet Comp Orthop Traumatol 2002; 15(01): 44-50
DOI: 10.1055/s-0038-1632712
Original Research
Schattauer GmbH

Effects of wire tension on the biomechanics of asymmetric four-ring circular external skeletal fixator constructs

A. R. Cross
1   Department of Small Animal Clinical Sciences and the Centre for Veterinary Sports Medicine, Gainesville, FL, USA
,
D. D. Lewis
1   Department of Small Animal Clinical Sciences and the Centre for Veterinary Sports Medicine, Gainesville, FL, USA
,
S. Rigaud
2   The department of Aerospace Engineering, Mechanics and Engineering Science, University of Florida, Gainesville, FL, USA
,
G. B. Mackinzie
1   Department of Small Animal Clinical Sciences and the Centre for Veterinary Sports Medicine, Gainesville, FL, USA
,
A. J. Rapoff
2   The department of Aerospace Engineering, Mechanics and Engineering Science, University of Florida, Gainesville, FL, USA
› Author AffiliationsThe authors would like to thank D. Sundstrom and R. Sammy for technical assistance.
Further Information

Publication History

Received 13 July 2001

Accepted 01 October 2001

Publication Date:
08 February 2018 (online)

Also available at
    Permissions and Reprints

Summary

This study evaluated the effects of fixation wire tension (0 kg, 30 kg, 60 kg, and 90 kg) on the biomechanics of a four ring asymmetric circular external fixator construct in four testing modes (axial compression, medio-lateral bending, craniocaudal bending, and torsional loading) using a gap fracture model. Wire tension had a significant direct effect on gap stiffness in all of the testing modes. Axial compression load-deformation curves exhibited non-linearity, characteristic of the self-tensioning effect observed with fine wire fixation. Bending loaddeformation curves had two discrete linear segments, attributable to slipping of the bone models on the fixation wires, once a critical bending moment was exceeded. Torsional loading caused a gradual ‘windup’ of the construct which was followed by a linear load-displacement curve. Increasing wire tension had a small but significant effect on gap stiffness, which generally diminished as higher tensions were applied, thus demonstrating the need for adequate initial construct design to achieve sufficient stability during fracture healing.

Keywords

llizarov - Circular External Skeletal Fixator - Biomechanics

* Funding for this project was provided by the Florida Pari-Mutuel Wagering Trust Fund Grant Competition.


College of Veterinary Medicine Journal Series Number 597, No reprints available


 

  • References

  • 1 Bronson DG, Samchukov ML, Birch JG. et al. Stability of external circular fixation: A multi-variable biomechanical analysis. Clin Biomech 1998; 13: 441-8.
    CrossrefPubMedGoogle Scholar
  • 2 Calhoun JH, Fan L, Ledbetter BR. Biomechanics of the Ilizarov fixator for fracture fixation. Clin Orthop 1992; 28: 15-22.
    PubMedGoogle Scholar
  • 3 Cross AR, Lewis DD, Murphy ST. et al. Effects of ring diameter and wire tension on the axial biomechanics of four-ring circular external skeletal fixator constructions. Am J Vet Res 2001; 62: 1025-30.
    CrossrefPubMedGoogle Scholar
  • 4 Elkins AD, Morandi M. The Ilizarov ring fixator: Principles, techniques, and uses. In: Slatter DH. ed. Textbook of small animal surgery. Vol II (2nd ed). Philadelphia: WB Saunders; 1993: 1656-61.
    Google Scholar
  • 5 Elkins AD, Morandi M, Zembo M. Distraction osteogenesis in the dog using the Ilizarov external ring fixator. J Am Anim Hosp Assoc 1993; 29: 19-26.
    PubMedGoogle Scholar
  • 6 Ferretti A. The application of the Ilizarov technique to veterinary medicine. In: Bianchi-Maiocchi A, Aronson J. eds. Operative principals of Ilizarov. Milan, Italy: Medi Surgical Vido; 1991: 551-70.
    Google Scholar
  • 7 Fleming B, Paley D, Kristiansen T. et al. A biomechanical analysis of the Ilizarov external fixator. Clin Orthop 1989; 25: 95-105.
    PubMedGoogle Scholar
  • 8 Gasser B, Boman B, Wyder D. et al. Stiffness characteristics of the circular Ilizarov device as opposed to conventional external fixation. J Bio Eng 1990; 112: 15-21.
    PubMedGoogle Scholar
  • 9 Hillard PJ, Harrison AJ, Atkins RM. The yielding of tensioned fine wires in the Ilizarov frame. Proc Inst Mech Engrs 1998; 212 Part H: 37-47.
    CrossrefPubMedGoogle Scholar
  • 10 Ilizarov GA. The apparatus: Components and biomechanical principles of application. In: Ilizarov GA. ed. Transosseous osteosynthesis. Theoretical and clinical aspects of the regeneration and growth of tissue. Berlin: Springer-Verlag; 1992: 63-136.
    Google Scholar
  • 11 Kummer F. Biomechanics of the Ilizarov external fixator. Clin Orthop 1992; 280: 11-4.
    PubMedGoogle Scholar
  • 12 Langley-Hobbs SJ, Carmichael S, Pead MJ. et al. Management of antebrachial deformity and shortening secondary to a synostosis in a dog. J Small Anim Pract 1996; 37: 359-63.
    CrossrefPubMedGoogle Scholar
  • 13 Lesser AS. Ilizarov technique. In: Bojrab MJ. ed. Current techniques in small animal surgery. 4th ed. Baltimore: Williams & Wilkins; 1998: 950-63.
    Google Scholar
  • 14 Lewis DD, Bronson DG, Cross AR, Welch RD, Kubilis PS. Axial characteristics of circular external skeletal fixator single ring constructions. Vet Surg 2001; 30: 386-94.
    CrossrefPubMedGoogle Scholar
  • 15 Lewis DD, Bronson DG, Samchukov ML. et al. Biomechanics of circular external skeletal fixation. Vet Surg 1998; 27: 454-64.
    CrossrefPubMedGoogle Scholar
  • 16 Lewis DD, Radasch RM, Beale BS. et al. Initial clinical experience with the IMEXJ circular external skeletal fixation system. Part I: Use in fractures and arthrodesis. Vet Comp Orthop Traumatol 1999; 12: 108-17.
    Article in Thieme ConnectPubMedGoogle Scholar
  • 17 Lewis DD, Radasch RM, Beale BS. et al. Initial clinical experience with the IMEXJ circular external skeletal fixation system. Part II: Use in bone lengthening and correction of angular and rotational deformities. Vet Comp Orthop Traumatol 1999; 12: 118-27.
    Article in Thieme ConnectPubMedGoogle Scholar
  • 18 Markel M, Sielman E, Rapoff AJ. et al. Mechanical properties of long bones in dogs. Am J Vet Res 1994; 55: 1178-83.
    PubMedGoogle Scholar
  • 19 Marcellin-Little DJ, Ferretti A, Roe SC. et al. Hinged Ilizarov external fixation for correction of antebrachial deformities. Vet Surg 1998; 27: 231-45.
    CrossrefPubMedGoogle Scholar
  • 20 Marcellin-Little DJ. Fracture treatment with circular external fixation. Vet Clin North Am Small Anim Pract 1999; 29: 1153-70.
    CrossrefPubMedGoogle Scholar
  • 21 Orbay GL, Frankel VH, Kummer FJ. The effect of wire configuration on the stiffness of the Ilizarov external fixator. Clin Orthop 1992; 279: 299-302.
    PubMedGoogle Scholar
  • 22 Owen MA. Use of the Ilizarov method to manage a septic tibial fracture nonunion with a large cortical defect. J Sm Anim Pract 2000; 41: 124-7.
    CrossrefPubMedGoogle Scholar
  • 23 Paley D. Biomechanics of the Ilizarov-external fixator. In: Bianchi-Maiocchi A, Aronson J. eds. Operative principals of Ilizarov. Milan, Italy: Medi Surgical Vido; 1991: 33-41.
    Google Scholar
  • 24 Podolsky A, Chao EYS. Mechanical performance of Ilizarov circular external fixators in comparison with other external fixators. Clin Orthop 1993; 29: 61-70.
    PubMedGoogle Scholar
  • 25 Preston CA. Distraction osteogenesis to treat premature distal radial growth plate closure in a dog. Aust Vet J 2000; 78: 387-91.
    CrossrefPubMedGoogle Scholar
  • 26 Tommasini MD, Betts CW. Use of the ‘Ilizarov’ external fixator in a dog. Vet Comp Orthop Traumatol 1991; 04: 70-6.
    Article in Thieme ConnectPubMedGoogle Scholar
  • 27 Trostel CT, Radasch RM. Tarsocrural arthrodesis: A clinical report using a circular external fixator. Vet Comp Orthop Traumatol 1998; 11: 193-6.
    Article in Thieme ConnectPubMedGoogle Scholar