Comparison of the mechanical behaviors of semicontoured, locking plate–rod fixation and anatomically contoured, conventional plate–rod fixation applied to experimentally induced gap fractures in canine femora

Clara S. S. Goh Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523.

Search for other papers by Clara S. S. Goh in
Current site
Google Scholar
PubMed
Close
 BVSc
,
Brandon G. Santoni Department of Mechanical Engineering, School of Biomedical Engineering, Colorado State University, Fort Collins, CO 80523.

Search for other papers by Brandon G. Santoni in
Current site
Google Scholar
PubMed
Close
 PhD
,
Christian M. Puttlitz Department of Mechanical Engineering, School of Biomedical Engineering, Colorado State University, Fort Collins, CO 80523.

Search for other papers by Christian M. Puttlitz in
Current site
Google Scholar
PubMed
Close
 PhD
, and
Ross H. Palmer Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Department of Mechanical Engineering, School of Biomedical Engineering, Colorado State University, Fort Collins, CO 80523.

Search for other papers by Ross H. Palmer in
Current site
Google Scholar
PubMed
Close
 DVM, MS

Abstract

Objective—To compare the mechanical behaviors of a semicontoured, locking compression plate–rod (LCP-rod) construct and an anatomically contoured, limited-contact dynamic compression plate–rod (LC–DCP-rod) construct applied to experimentally induced gap fractures in canine femora.

Sample Population—16 femora from 8 cadaveric dogs.

Procedures—8 limbs from 8 dogs were assigned to the LCP-rod construct group or the LC–DCP-rod construct group. In each femur, a 39-mm mid-diaphyseal ostectomy was performed at the same plate location and the assigned construct was applied. Construct stiffness and ostectomy gap subsidence were determined before and after cyclic axial loading (6,000 cycles at 20%, 40%, and 60% of live body weight [total, 18,000 cycles]). Three constructs from each group further underwent 45,000 cycles at 60% of body weight (total, 63,000 cycles). Following cyclic loading, mode of failure during loading to failure at 5 mm/min was recorded for all constructs.

Results—After 18,000 or 63,000 cycles, construct stiffness did not differ significantly between construct groups. No implant failure occurred in any construct that underwent 63,000 cycles. In both construct groups, ostectomy gap subsidence similarly increased as axial load increased but did not change after 18,000 cycles. Mean ± SEM loads at failure in the LCP-rod (1,493.83 ± 200.12 N) and LC–DCP-rod (1,276.05 ± 156.11 N) construct groups were not significantly different. The primary failure event in all constructs occurred at the screw hole immediately distal to the ostectomy.

Conclusions and Clinical Relevance—Biomechanically, the semicontoured LCP-rod construct is similar to the anatomically contoured LC–DCP-rod system.

Abstract

Objective—To compare the mechanical behaviors of a semicontoured, locking compression plate–rod (LCP-rod) construct and an anatomically contoured, limited-contact dynamic compression plate–rod (LC–DCP-rod) construct applied to experimentally induced gap fractures in canine femora.

Sample Population—16 femora from 8 cadaveric dogs.

Procedures—8 limbs from 8 dogs were assigned to the LCP-rod construct group or the LC–DCP-rod construct group. In each femur, a 39-mm mid-diaphyseal ostectomy was performed at the same plate location and the assigned construct was applied. Construct stiffness and ostectomy gap subsidence were determined before and after cyclic axial loading (6,000 cycles at 20%, 40%, and 60% of live body weight [total, 18,000 cycles]). Three constructs from each group further underwent 45,000 cycles at 60% of body weight (total, 63,000 cycles). Following cyclic loading, mode of failure during loading to failure at 5 mm/min was recorded for all constructs.

Results—After 18,000 or 63,000 cycles, construct stiffness did not differ significantly between construct groups. No implant failure occurred in any construct that underwent 63,000 cycles. In both construct groups, ostectomy gap subsidence similarly increased as axial load increased but did not change after 18,000 cycles. Mean ± SEM loads at failure in the LCP-rod (1,493.83 ± 200.12 N) and LC–DCP-rod (1,276.05 ± 156.11 N) construct groups were not significantly different. The primary failure event in all constructs occurred at the screw hole immediately distal to the ostectomy.

Conclusions and Clinical Relevance—Biomechanically, the semicontoured LCP-rod construct is similar to the anatomically contoured LC–DCP-rod system.

  • 1.

    Unger M, Montavon PM, Heim UFA. Classification of fractures of long bones in the dog and cat: introduction and clinical application. Vet Comp Orthop Traumatol 1990;3:4150.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 2.

    Perren SM. The concept of biological plating using the limited contact-dynamic compression plate (LC-DCP). Scientific background, design and application. Injury 1991;22(suppl 1):141.

    • Search Google Scholar
    • Export Citation
  • 3.

    Gautier E, Sommer C. Guidelines for the clinical application of the LCP. Injury 2003;34:S-B63S-B76.

  • 4.

    Wagner M. General principles for the clinical use of the LCP. Injury 2003;34:S-B31S-B42.

  • 5.

    Korner J, Lill H, Muller LP, et al. The LCP-concept in the operative treatment of distal humerus fractures—biological, biomechanical and surgical aspects. Injury 2003;34:S-B20S-B30.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 6.

    Hedequist DJ, Sink E. Technical aspects of bridge plating for pediatric femur fractures. J Orthop Trauma 2005;19:276279.

  • 7.

    Farouk O, Krettek C, Miclau T, et al. Effects of percutaneous and conventional plating techniques on the blood supply to the femur. Arch Orthop Trauma Surg 1998;117:438441.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 8.

    Schmökel HG, Stein S, Radke H, et al. Treatment of tibial fractures with plates using minimally invasive percutaneous osteosynthesis in dogs and cats. J Small Anim Pract 2007;48:157160.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 9.

    Hulse D, Hyman W, Nori M, et al. Reduction in plate strain by addition of an intramedullary pin. Vet Surg 1997;26:451459.

  • 10.

    Hulse D, Ferry K, Fawcett A, et al. Effect of intramedullary pin size on reducing bone plate strain. Vet Comp Orthop Traumatol 2000;13:185190.

  • 11.

    Kessler SB, Deiler S, Schiffl-Deiler M, et al. Refractures: a consequence of impaired local bone viability. Arch Orthop Trauma Surg 1992;111:96101.

  • 12.

    Perren SM. Evolution of the internal fixation of long bone fractures. The scientific basis of biological internal fixation: choosing a new balance between stability and biology. J Bone Joint Surg Br 2002;84:10931110.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 13.

    Frigg R. Locking compression plate (LCP). An osteosynthesis plate based on the dynamic compression plate and point contact fixator (PC-Fix). Injury 2001;32:6366.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 14.

    Sommer C, Gautier E, Muller M, et al. First clinical results of the locking compression plate (LCP). Injury 2003;34:S-B43S-B54.

  • 15.

    Aguila AZ, Manos JM, Orlansky AS, et al. In vitro biomechanical comparison of limited contact dynamic compression plate and locking compression plate. Vet Comp Orthop Traumatol 2005;18:220226.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 16.

    Kirsch JA, Déjardin LM, DeCamp CE, et al. In vitro mechanical evaluation on the use of an intramedullary pin-plate combination for pantarsal arthrodesis in dogs. Am J Vet Res 2005;66:125131.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 17.

    DeCamp CE. Kinetic and kinematic gait analysis and the assessment of lameness in the dog. Vet Clin North Am Small Anim Pract 1997;27:825840.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 18.

    Aper RL, Litsky AS, Roe SC, et al. Effect of bone diameter and eccentric loading on fatigue life of cortical screws used with interlocking nails. Am J Vet Res 2003;64:569573.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 19.

    Bernarde A, Diop A, Maurel N, et al. An in vitro biomechanical study of bone plate and interlocking nail in a canine diaphyseal femoral fracture model. Vet Surg 2001;30:397408.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 20.

    Roush JK & McLaughlin RM Jr. Effects of subject stance time and velocity on ground reaction forces in clinically normal Greyhounds at the walk. Am J Vet Res 1994;55:16721676.

    • Search Google Scholar
    • Export Citation
  • 21.

    Budsberg SC, Verstraete MC, Soutas-Little RW. Force plate analysis of the walking gait in healthy dogs. Am J Vet Res 1987;48:915918.

  • 22.

    Bertram JEA, Lee DV, Case HN, et al. Comparison of the trotting gaits of Labrador Retrievers and Greyhounds. Am J Vet Res 2000;61:832838.

  • 23.

    Cheal EJ, Mansmann KA, DiGioia AM III, et al. Role of interfragmentary strain in fracture healing: ovine model of a healing osteotomy. J Orthop Res 1991;9:131142.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 24.

    Stoffel K, Dieter U, Stachowiak G, et al. Biomechanical testing of the LCP—how can stability in locked internal fixators be controlled? Injury 2003;34:S-B11S-B19.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 25.

    Markel MD, Sielman E, Bodganske JJ. Densitometric properties of long bones in dogs, as determined by use of dual-energy x-ray absorptiometry. Am J Vet Res 1994;55:17501756.

    • Search Google Scholar
    • Export Citation
  • 26.

    Markel MD, Sielman E, Rapoff AJ, et al. Mechanical properties of long bones in dogs. Am J Vet Res 1994;55:11781182.

  • 27.

    Johnson AL, Smith CW, Schaeffer DJ. Fragment reconstruction and bone plate fixation versus bridging plate fixation for treating highly comminuted femoral fractures in dogs: 35 cases (1987–1997). J Am Vet Med Assoc 1998;213:11571161.

    • Search Google Scholar
    • Export Citation
  • 28.

    Aron DN, Palmer RH, Johnson AL. Biologic strategies and a balanced concept for repair of highly comminuted long bone fractures. Compend Contin Educ Pract Vet 1995;17:3549.

    • Search Google Scholar
    • Export Citation

Advertisement