Download PDF
Vet Comp Orthop Traumatol 2020; 33(01): 036-044
DOI: 10.1055/s-0039-1698415
Original Research
Georg Thieme Verlag KG Stuttgart · New York

Mechanical Performance of a Polyaxial Locking Plate and the Influence of Screw Angulation in a Fracture Gap Model

Jakub Kaczmarek
1   AniCura Kleintierspezialisten Augsburg, Augsburg, Germany
,
Tomasz Bartkowiak 
2   Poznan University of Technology, Poznan, Poland
,
Riccarda Schuenemann
1   AniCura Kleintierspezialisten Augsburg, Augsburg, Germany
,
Piotr Paczos
2   Poznan University of Technology, Poznan, Poland
,
Bartosz Gapinski
2   Poznan University of Technology, Poznan, Poland
,
Sandra Bogisch
1   AniCura Kleintierspezialisten Augsburg, Augsburg, Germany
,
Martin Unger
1   AniCura Kleintierspezialisten Augsburg, Augsburg, Germany
› Author Affiliations Funding This study was financially supported by the AniCura GmbH—AniCura Research Found. Implants for this study were donated from Aesculap B. Braun Vet Care and DePuy Synthes.
Further Information

Publication History

22 December 2018

03 September 2019

Publication Date:
18 October 2019 (online)

    Permissions and Reprints

Abstract

Objective The aim of this study was to compare the locking compression plate (LCP) with polyaxial locking system (PLS) using single cycle to failure 4-point bending test and to investigate the behaviour of PLS with screws inserted mono- and polyaxially using cyclic fatigue test in two bending directions.

Materials and Methods Tests were performed on bone surrogates in a fracture gap model. The 3.5 LCP and 3.5 PLS plates were tested in single cycle to failure. The 3.5 PLS plates with mono- and polyaxial screws were compared in a cyclic fatigue tests in two orthogonal directions. For both experiments, micro-computed tomography (CT) scans were performed pre- and post-testing to investigate the connections between the screw head and the plate hole. Means of forces and cycles needed to failure were statistically compared.

Results The PLS plates were on average 30% weaker than LCP plates. Mode of failure was plate bending in the single cycle to failure tests, and plate breakage in the cyclic fatigue tests. Neither screw breakage nor loss of the screw–plate interface occurred. Mono- and polyaxial constructs performed similarly when loaded in the same direction. Micro-CT revealed no additional internal cracks in the plates or screws after testing. It also showed for both PLS and LCP that there was only partial contact of the screw head with the plate hole.

Clinical Relevance PLS offers a durable locking system, even when the screws are placed polyaxially. The weaker bending properties of the PLS compared with LCP should be considered during preoperative planning.

Keywords

locking plate - micro-CT - bending - locking screws - polyaxial

Note

Results of this study were presented at the 5th WVOC Conference in Barcelona, Spain, September 2018 and was awarded as the Best Free Communication.


Authors' Contributions

Jakub Kaczmarek and Martin Unger contributed to conception of study, study design, acquisition of data and data analysis and interpretation. Riccarda Schuenemann, Sandra Bogisch contributed to conception of study, study design and data analysis and interpretation. Tomasz Bartkowiak, Bartosz Gapinski and Piotr Paczos contributed to acquisition of data and data analysis and interpretation. All authors drafted, revised and approved the submitted manuscript.


 

  • References

  • 1 Hak DJ, Banegas R, Ipaktchi K, Mauffrey C. Evolution of plate design and material composition. Injury 2018; 49 (June, Suppl 1): S8-S11
    CrossrefPubMedGoogle Scholar
  • 2 Gautier E, Sommer C. Guidelines for the clinical application of the LCP. Injury 2003; 34 (Suppl. 02) B63-B76
    CrossrefPubMedGoogle Scholar
  • 3 Bel JC. Pitfalls and limits of locking plates. Orthop Traumatol Surg Res 2019; 105 (1S): S103-S109
    CrossrefPubMedGoogle Scholar
  • 4 Kääb MJ, Frenk A, Schmeling A, Schaser K, Schütz M, Haas NP. Locked internal fixator: sensitivity of screw/plate stability to the correct insertion angle of the screw. J Orthop Trauma 2004; 18 (08) 483-487
    CrossrefPubMedGoogle Scholar
  • 5 Schoch B, Hast MW, Mehta S, Namdari S. Not all polyaxial locking screw technologies are created equal: a systematic review of the literature. JBJS Rev 2018; 6 (01) e6
    PubMedGoogle Scholar
  • 6 Barnhart MD, Rides CF, Kennedy SC. , et al. Fracture repair using a polyaxial locking plate system (PAX). Vet Surg 2013; 42 (01) 60-66
    CrossrefPubMedGoogle Scholar
  • 7 Hallbauer J, Klos K, Gräfenstein A. , et al. Does a polyaxial-locking system confer benefits for osteosynthesis of the distal fibula: a cadaver study. Orthop Traumatol Surg Res 2016; 102 (05) 645-649
    CrossrefPubMedGoogle Scholar
  • 8 Klug A, Gramlich Y, Buckup J, Wincheringer D, Hoffmann R, Schmidt-Horlohé K. Excellent results and low complication rate for anatomic polyaxial locking plates in comminuted proximal ulna fractures. J Shoulder Elbow Surg 2018; 27 (12) 2198-2206
    CrossrefPubMedGoogle Scholar
  • 9 Hallbauer J, Gräfenstein A, Rausch S. , et al. Biomechanical analysis of polyaxial locking vs. non-locking plate fixation of unstable fractures of the distal fibula: a cadaver study with a bone only model. Foot Ankle Surg 2018; 24 (04) 326-329
    CrossrefPubMedGoogle Scholar
  • 10 Al-Mouazzen L, Chou DT, Kyriakopoulos G, Hambidge J. Polyaxial versus uniaxial volar locking plate for distal radial fractures. J Orthop Surg (Hong Kong) 2014; 22 (01) 9-12
    CrossrefPubMedGoogle Scholar
  • 11 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 (03) 146-152
    Article in Thieme ConnectPubMedGoogle Scholar
  • 12 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 (06) 408-417
    Article in Thieme ConnectPubMedGoogle Scholar
  • 13 American Society for Testing and Materials. Standard Specification and Test Method for Metallic Bone Plates, ASTM F382–99 (Reapproved 2003). In: 2003 Annual Book of ASTM Standards. West Conshohocken, PA: ASTM; 2003
    Google Scholar
  • 14 Bufkin BW, Barnhart MD, Kazanovicz AJ, Naber SJ, Kennedy SC. 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 (03) 186-191
    Article in Thieme ConnectPubMedGoogle Scholar
  • 15 Malenfant RC, Sod GA. In vitro biomechanical comparison of 3.5 string of pearl plate fixation to 3.5 locking compression plate fixation in a canine fracture gap model. Vet Surg 2014; 43 (04) 465-470
    CrossrefPubMedGoogle Scholar
  • 16 Bilmont A, Palierne S, Verset M, Swider P, Autefage A. Biomechanical comparison of two locking plate constructs under cyclic torsional loading in a fracture gap model. Vet Comp Orthop Traumatol 2015; 28 (05) 323-330
    Article in Thieme ConnectPubMedGoogle Scholar
  • 17 Bertram JE, Lee DV, Case HN, Todhunter RJ. Comparison of the trotting gaits of Labrador Retrievers and Greyhounds. Am J Vet Res 2000; 61 (07) 832-838
    CrossrefPubMedGoogle Scholar
  • 18 Demner D, Garcia TC, Serdy MG, Hayashi K, Nir BA, Stover SM. Biomechanical comparison of mono- and bicortical screws in an experimentally induced gap fracture. Vet Comp Orthop Traumatol 2014; 27 (06) 422-429
    Article in Thieme ConnectPubMedGoogle Scholar
  • 19 Pearson T, Glyde M, Hosgood G, Day R. The effect of intramedullary pin size and monocortical screw configuration on locking compression plate-rod constructs in an in vitro fracture gap model. Vet Comp Orthop Traumatol 2015; 28 (02) 95-103
    Article in Thieme ConnectPubMedGoogle Scholar
  • 20 Benamou J, Demianiuk RM, Rutherford S. , et al. Effect of bending direction on the mechanical behaviour of 3.5 mm String-of-Pearls and Limited Contact Dynamic Compression Plate constructs. Vet Comp Orthop Traumatol 2015; 28 (06) 433-440
    Article in Thieme ConnectPubMedGoogle Scholar
  • 21 Tomlinson AW, Comerford EJ, Birch RS, Innes JF, Walton MB. Mechanical performance in axial compression of a titanium polyaxial locking plate system in a fracture gap model. Vet Comp Orthop Traumatol 2015; 28 (02) 88-94
    Article in Thieme ConnectPubMedGoogle Scholar
  • 22 Watrous GK, Moens NMM, Runciman J, Gibson TWG. Biomechanical properties of the 1.5 mm locking compression plate: comparison with the 1.5 and 2.0 mm straight plates in compression and torsion. Vet Comp Orthop Traumatol 2018; 31 (06) 438-444
    Article in Thieme ConnectPubMedGoogle Scholar
  • 23 Rotne R, Bertollo N, Walsh W, Dhand NK, Voss K, Johnson KA. Influence of plate-bone contact on cyclically loaded conically coupled locking plate failure. Injury 2014; 45 (03) 515-521
    CrossrefPubMedGoogle Scholar