Vet Comp Orthop Traumatol 2017; 30(03): 172-177
DOI: 10.3415/VCOT-16-07-0111
Original Research
Schattauer GmbH

Single cycle to failure in bending of three titanium polyaxial locking plates

Chadi Eid
1   Ortovet stp srl, Fidenza, Italy
,
Filippo Maria Martini
1   Ortovet stp srl, Fidenza, Italy
2   University of Parma, School of Veterinary Medicine, Parma, Italy
,
Andrea Bonardi
1   Ortovet stp srl, Fidenza, Italy
,
Filippo Lusetti
1   Ortovet stp srl, Fidenza, Italy
,
Anna Brandstetter de Belesini
1   Ortovet stp srl, Fidenza, Italy
,
Gianni Nicoletto
3   University of Parma, Department of Industrial Engineering, Parma, Italy
› Author Affiliations
Further Information

Publication History

Received: 23 July 2016

Accepted: 07 February 2017

Publication Date:
23 December 2017 (online)

Summary

Objective: Evaluation of the bending properties in one direction of three titanium polyaxial locking plate systems.

Materials and methods: The Polyaxial Advanced Locking System (PAX®) straight plate (PAX SP), the PAX® reconstruction plate (PAX RP), and the VetLOX reconstruction plates (VetLOX) were evaluated individually and as constructs applied to a bone model simulating a fracture gap and compared using a two-way analysis of variance and Tukey posthoc analysis.

Results: The PAX SP had the highest values of bending stiffness, bending structural stiffness and bending strength. When tested as plates alone, the PAX RP and VetLOX showed no differences with regard to bending stiffness and bending structural stiffness, whilst the PAX RP had significantly higher strength. The PAX RP construct had significantly higher bending stiffness, bending structural stiffness and bending strength than the VetLOX construct.

Clinical relevance: The PAX RP and VetLOX reconstruction plates are much more likely to fail when used as bridging implants, thus adjunct support is needed. The lower bending strength of the VetLOX reconstruction plates suggests it should not be used in fractures under high loads.

 
  • References

  • 1 Hudson CC, Pozzi A, Lewis DD. Minimally invasive plate osteosynthesis: applications and techniques in dogs and cats. Vet Comp Orthop Traumatol 2009; 22: 175-182.
  • 2 Hulse D, Hyman W, Nori M. et al. Reduction in plate strain by addition of an intramedullary pin. Vet Surg 1997; 26: 451-469.
  • 3 Johnson AL. Current concepts in fracture reduction. Vet Comp Orthop Traumatol 2003; 16: 59-66.
  • 4 Wagner M. General principles for the clinical use of the LCP. Injury 2003; 34 (Suppl. 02) Suppl B31-42.
  • 5 Haidukewych GJ. Innovations in locking plate technology. J Am Acad Orthop Surg 2004; 12: 205-212.
  • 6 Szypryt P, Forward D. The use and abuse of locking plates. Orthopaedics and Trauma 2009; 23: 281-290.
  • 7 Haidukewych GJ, Ricci W. Locked plating in orthopaedic trauma: A clinical update. J Am Acad Orthop Surg 2008; 16: 347-355.
  • 8 Cronier P, Pietu G, Dujardin C. et al. The concept of locking plates. Orthop Traumatol Surg Research 2010; 96: S17-36.
  • 9 Gautier E, Sommer C. Guidelines for the clinical application of the LCP. Injury 2003; 34 (Suppl. 02) Suppl B63-76.
  • 10 Kääb MJ, Frenk A, Schmelling A. et al. Locked internal fixator. Sensitivity of screw plate stability to the correct insertion angle of the screw. J Orthop Trauma 2004; 18: 483-487.
  • 11 Sommer C. Biomechanics and clinical application principles of locking plates. Suomen Ortopedia ja Traumatologia 2006; 29: 20-24.
  • 12 Barnhart MD, Rides CF, Kennedy SC. et al. Fracture repair using a polyaxial locking plate system (PAX). Vet Surg 2013; 42: 60-66.
  • 13 Dickomeit M, Alves L, Pekarkova M. et al. Use of a 1.5 mm butterfly locking plate for stabilization of atlantoaxial pathology in three toy breed dogs. Vet Comp Orthop Traumatol 2011; 24: 246-251.
  • 14 Bufkin BW, Barnhart MD, Kazanovicz AJ. et al. The effect of screw angulation and insertion torque on the push-out strength of polyaxial locking screws and the single cycle to failure in bending of polyaxial locking plates. Vet Comp Orthop Traumatol 2013; 26: 186-191.
  • 15 Tomlinson AW, Comerford EJ, Birch RS. et al. Mechanical performance in axial compression of a titanium polyaxial locking plate system in a fracture gap model. Vet Comp Orthop Traumatol 2015; 28: 88-94.
  • 16 Blake CA, Boudrieau RJ, Torrance BS. et al. Single cycle to failure in bending of three standard and five locking plates and plate constructs. Vet Comp Orthop Traumatol 2011; 24: 408-417.
  • 17 Chao P, Conrad BP, Lewis DD. et al. Effect of plate working length on plate stiffness and cyclic fatigue life in a cadaveric femoral fracture gap model stabilized with a 12-hole 2.4 mm locking compression plate. BMC Vet Res 2013; 9: 125-131.
  • 18 Benamou J, Demianiuk RM, Rutherford S. et al. Effect of bending direction on the mechanical behaviour of 3.5mm String-of-Pearls and Limited Contact Dynamic Compression Plate constructs. Vet Comp Orthop Traumatol 2015; 28: 433-440.
  • 19 Muir P, Johnson KA, Markel MD. Area moment of inertia for comparison of implant cross-sectional geometry and bending stiffness. Vet Comp Orthop Traumatol 1995; 8: 146-152.
  • 20 American Society for Testing and Materials. Standard Specification and Test Method for Metallic Bone Plates, ASTM F382-99 (Reapproved 2008). In: 2008 Annual Book of ASTM Standards. West Conshohocken, PA: ASTM 2008; 4-7.
  • 21 Chao P, Lewis DD, Kowaleski MP. et al. Biomechanical concepts applicable to minimally invasive fracture repair in small animals. Vet Clin Small Anim 2012; 42: 853-872.
  • 22 Pearson T, Glyde MR, Day RE. et al. The effect of intramedullary pin size and plate working length on plate strain in locking compression plate- rod constructs under axial load. Vet Comp Orthop Traumatol 2016; 29: 451-458.
  • 23 Johnson KA. Locking plates - The ultimate implant?. Vet Comp Orthop Traumatol 2009; 22 (02) I-II.
  • 24 Wilkens KJ, Curtiss S, Lee M. Polyaxial locking plate fixation in distal femur fractures: a biomechanical comparison. J Orth trauma 2008; 22: 624-628.
  • 25 Cullen AB, Curtiss S, Lee MA. Biomechanical comparison of polyaxial and uniaxial locking plate fixation in a proximal tibial gap model. J Orthop Trauma 2009; 23: 507-513.
  • 26 Zettl R, Müller T, Topp T. et al. Monoaxial versus polyaxial locking systems: a biomechanical analysis of different locking systems for the fixation of proximal humeral fractures. Int Orthop 2011; 35: 1245-1250.