Tierarztl Prax Ausg K Kleintiere Heimtiere 2014; 42(02): 79-87
DOI: 10.1055/s-0038-1623747
Original Article
Schattauer GmbH

In vitro biomechanical comparison of a newly designed interlocking nail system to a standard DCP

Testing of cat femora in an osteotomy gap modelIn-vitro-Testung eines neuartigen Verriegelungsnagels im Vergleich zu einer Standard-DCPEvaluierung an Katzenfemora in einem “Osteotomiespalt-Modell”
M. Brückner
1   Small Animal Clinic of Augsburg, Augsburg, Germany
,
M. Unger
1   Small Animal Clinic of Augsburg, Augsburg, Germany
,
M. Spies
2   B. Braun Vet Care GmbH, Tuttlingen, Germany
› Institutsangaben
Weitere Informationen

Publikationsverlauf

Received: 09. Mai 2013

Accepted after revision: 13. Juni 2013

Publikationsdatum:
06. Januar 2018 (online)

Summary

Objective: To describe a newly designed interlocking nail system (Targon® Vet System, TVS) tested in a model of diaphyseal femoral fractures in cats. Material and methods: Introduction of the TVS and presentation of the system components. Evaluation of application range and biomechanical testing of the TVS in cadaver bones under cyclic loading until fatigue failure occurred. The first two test groups compared the influence of implantation and immediate removal of the TVS locking bolts and six holes created by 2.0 mm cortical screws on the stability of feline femora. In the third group the two fixation systems were compared to each other with implants in place in an osteotomy gap model. The failure mode was statistically compared for each group (p < 0.05). Results: Femora after implantation and removal of the bolts of the TVS were significantly stiffer than after implantation and removal of the six 2.0 mm cortical screws. In the osteotomy gap model, femora with the TVS in place failed somewhat later, but not statistically significant, than the opposite femur of the same cat with the 2.0 8-hole DCP in place. Conclusion and clinical relevance: Using this testing method, stability of the TVS seems to be biomechanically comparable to conventional osteosynthesis plate systems. Therefore the TVS may be an encouraging alternative to conventional osteosynthesis systems in diaphyseal fractures, offering several advantages without the need for extensive specialized equipment.

Zusammenfassung

Gegenstand und Ziel: Beschreibung eines neuartigen Verriege-lungs nagel-Systems (Targon® Vet System, TVS) und Testung dieses Systems in einem In-vitro-Modell an Katzenfemora mit diaphysären Frakturen. Material und Methode: Beschreibung des Systems und der einzelnen Systemkomponenten. Ermittlung der Mindestgröße für die Anwendung des TVS und biomechanische Testung des TVS in Kadaverknochen unter zyklischer Belastung bis zum Eintreten einer Ermüdungsfraktur. In den ersten beiden Testgruppen wurde vergleichend untersucht, wie sich die Implantation und anschließende Entfernung eines TVS-Verriegelungsbolzens bzw. sechs 2,0-mm-Kortikalschrauben auf die Stabilität von Katzenfemora auswirkt. In der dritten Testgruppe erfolgte ein Vergleich beider Implantatsysteme in einem “Osteotomiespalt-Modell”. Das Versagen des jeweiligen Knochens bzw. Implantat-Knochen-Konstrukts wurde zwischen den Gruppen statistisch verglichen (p < 0,05). Ergebnisse: Die Femora nach Implantation und Entfernung der Verriegelungsbolzen waren signifikant stabiler als diejenigen nach Implantation und Entfernung von sechs 2,0-mm-Kortikalschrauben. Im „Osteotomiespalt-Modell” erwiesen sich die Femora mit dem implantierten TVS als geringfügig stabiler im Vergleich zum jeweils kontralateralen, mit einer 2,0 DCP und sechs Kortikalschrauben fixierten Femur, doch war der Unterschied statistisch nicht signifikant. Schlussfolgerung und klinische Relevanz: Die Stabilität des TVS ist unter diesen Testbedingungen biomechanisch vergleichbar zu der konventioneller Plattensysteme für die Osteosynthese. Das TVS könnte bei diaphysären Frakturen eine vielversprechende Alternative zu konventionellen Osteosynthesesystemen darstellen und bietet verschiedene Vorteile, ohne den Bedarf für ein umfangreiches spezielles Equipment.

 
  • References

  • 1 Basinger RR, Suber JT. Two techniques for supplementing interlocking nail repair of fractures of the humerus, femur, and tibia: results in 12 dogs and cats. Vet Surg 2004; 33 (06) 673-680.
  • 2 Beck AL, Pead MJ, draper E. Regional load bearing of the feline acetabulum. J Biomech 2005; 38: 427-432.
  • 3 Bernarde A, Diop A, Maurel N, Viguier E. An in vitro biomechanical study of bone plate and interlocking nail in a canine diaphyseal femoral fracture model. Vet Surg 2001; 30 (05) 397-408.
  • 4 Dejardin LM, Lansdowne JL, Sinnott MT. et al. In vitro mechanical evaluation of torsional loading in simulated canine tibiae for a novel hourglassshaped interlocking nail with a self-tapping tapered locking design. Am J Vet Res 2006; 67 (04) 678-685.
  • 5 Déjardin LM, Guillou RP, Ting D. et al. Effect of bending direction on the mechanical behaviour of interlocking nail systems. Vet Comp Orthop Traumatol 2009; 22 (04) 264-269.
  • 6 Díaz-Bertrana MC, Durall I, Puchol JL. et al. Interlocking nail treatment of long-bone fractures in cats: 33 cases (1995-2004). Vet Comp Orthop Traumatol 2005; 18 (03) 119-126.
  • 7 Dueland RT, Berglund L, Vanderby Jr R. et al. Structural properties of interlocking nails, canine femora, and femur-interlocking nail constructs. Vet Surg 1996; 25 (05) 386-396.
  • 8 Dueland RT, Johnson KA, Roe SC, Engen MH. et al. Interlocking nail treatment of diaphyseal long-bone fractures in dogs. J Am Vet Med Assoc 1999; 214 (01) 59-66.
  • 9 Duhautois B. Use of veterinary interlocking nails for diaphyseal fractures in dogs and cats: 121 cases. Vet Surg 2003; 32 (01) 8-20.
  • 10 Durall I, Diaz MC. Early experience with the use of an interlocking nail for the repair of canine femoral shaft fractures. Vet Surg 1996; 25 (05) 397-406.
  • 11 Durall I, Diaz-Bertona MC, Puchol JL. et al. Radiographic findings related to interlocking nailing: windshield-wiper effect, and locking screw failure. Vet Comp Orthop Traumatol 2003; 16 (04) 217-222.
  • 12 Durall I, Falcón C, Díaz-Bertrana MC. et al. Effects of static fixation and dynamization after interlocking femoral nailing locked with an external fixator: an experimental study in dogs. Vet Surg 2004; 33 (04) 323-332.
  • 13 Endo K, Nakamura K, Maeda H, Matsushita T. Interlocking intramedullary nail method for the treatment of femoral and tibial fractures in cats and small dogs. J Vet Med Sci 1998; 60 (01) 119-122.
  • 14 Gatineau M, Plante J. Ulnar interlocking intramedullary nail stabilization of a proximal radio-ulnar fracture in a dog. Vet Surg 2010; 1025-1029.
  • 15 Goett SD, Sinnott MT, Ting D. et al. Mechanical comparison of an interlocking nail locked with conventional bolts to extended bolts connected with a type-Ia external skeletal fixator in a tibial fracture model. Vet Surg 2007; 36 (03) 279-286.
  • 16 Horstman CL, Beale BS, Conzemius MG. et al. Biological osteosynthesis versus traditional anatomic reconstruction of 20 long-bone fractures using an interlocking nail: 1994-2001. Vet Surg 2004; 33 (03) 232-237.
  • 17 Johnston SA, von Pfeil DJF, Dejardin LM. et al. In: Veterinary Surgery Small Animal: Internal fracture fixation. St. Louis, Missouri: Saunders; 2012: 576-607.
  • 18 Lansdowne JL, Sinnott MT, Dejardin LM. et al. In vitro mechanical comparison of screwed, bolted, and novel interlocking nail systems to buttress plate fixation in torsion and mediolateral bending. Vet Surg 2007; 36 (04) 368-377.
  • 19 Larin A, Eich CS, Parker RB, Stubbs WP. Repair of diaphyseal femoral fractures in cats using interlocking intramedullary nails: 12 cases (1996-2000). J Am Vet Med Assoc 2001; 219 (08) 1098-104.
  • 20 Lu Y, Nemke B, Lorang DM. et al. Comparison of a new braid fixation system to an interlocking intramedullary nail for tibial osteotomy repair in an ovine model. Vet Surg 2009; 38 (04) 467-476.
  • 21 Moses PA, Lewis DD, Lanz OI. et al. Intramedullary interlocking nail stabilisation of 21 humeral fractures in 19 dogs and one cat. Aust Vet J 2002; 80 (06) 336-343.
  • 22 Muir P, Johnson KA, Markel MD. Area moment of interia for comparison of implant cross-sectional geometry and bending. Vet Comp Ortho Traumatol 1995; 08: 146-152.
  • 23 Muir P, Johnson KA. Interlocking intramedullary nail stabilization of a femoral fracture in a dog with osteomyelitis. J Am Vet Med Assoc 1996; 209 (07) 1262-1264.
  • 24 Patil DB, Adamiak Z, Piórek A. Veterinary interlocking nailing and its augmentation for fracture repair. Pol J Vet Sci 2008; 11 (02) 187-191.
  • 25 Pfeil DJ, Déjardin LM, DeCamp CE. et al. In vitro biomechanical comparison of a plate-rod combination-construct and an interlocking nail-construct for experimentally induced gap fractures in canine tibiae. Am J Vet Res 2005; 66 (09) 1536-1543.
  • 26 Radja D. Design and analysis of fatigue resistant welded structures. Abington Published. 1990: 71.
  • 27 Reems MR, Pluhar GE, Wheeler DL. Ex vivo comparison of one versus two distal screws in 8 mm model 11 interlocking nails used to stabilize canine distal femoral fractures. Vet Surg 2006; 35 (02) 161-167.
  • 28 Scotti S, Klein A, Pink J, Hidalgo A. et al. Retrograde placement of a novel 3.5 mm titanium interlocking nail for supracondylar and diaphyseal femoral fractures in cats. Vet Comp Orthop Traumatol 2007; 20 (03) 211-218.
  • 29 Stiffler KS. Internal fracture fixation. Clin Tech Small Anim Pract 2004; 19 (03) 105-113.
  • 30 Ting D, Cabassu JB, Guillou RP. et al. In vitro evaluation of the effect of fracture configuration on the mechanical properties of standard and novel interlocking nail systems in bending. Vet Surg 2009; 38 (07) 881-887.