title: Biomechanical comparison of anatomical plating systems for comminuted distal humeral fractures.
abstract: Six different mono-axial and poly-axial distal humeral plating systems with an anatomical plate design were compared. The aim of the biomechanical tests was to examine differences regarding system stiffness, median fatigue limit, and failure mechanisms.
  
  
  
  Different configurations of two double plate fixation systems by two manufacturers for the treatment of complex distal humeral fractures (AO/OTA type C2.3) were biomechanically tested in a physiologically relevant setup.
  
  
  
  The 180° Stryker configuration presented itself as the system with the highest stiffness, being significantly stiffer (p < 0.001) than every system other than the poly-axial 180° aap system (p = 0.378). For the median fatigue limit the 180° Stryker and poly-axial aap systems were ranked first and second. The failure mechanism for all 90° systems was a fatigue breakage of the posterolateral plate. The 180° aap systems demonstrated breakage of the most distal screws of the lateral plate. The 180° Stryker system demonstrated screw breakage on both the medial and lateral plates.
  
  
  
  Breakage of the posterolateral plate as a failure mechanism for the 90° systems was expected. The 180° systems demonstrated a higher stiffness compared to the 90° constructs for the axial loading. In conclusion, both poly-axial anatomical plating systems provide sufficient stability in this scenario, and the 180° configurations demonstrated superior stiffness.
authors.affiliation: Institute of Biomechanics, Paracelsus Medical University, Salzburg, Austria. p.varady@ibmb.tu-bs.de.|Institute of Biomechanics, Trauma Centre Murnau, Professor Küntscher Str. 8, 82418, Murnau, Germany. p.varady@ibmb.tu-bs.de.
authors.forename: Patrick A
authors.initials: PA
authors.lastname: Varady
authors.affiliation: Institute of Biomechanics, Paracelsus Medical University, Salzburg, Austria.|Institute of Biomechanics, Trauma Centre Murnau, Professor Küntscher Str. 8, 82418, Murnau, Germany.|Department of Trauma Surgery, Trauma Centre Murnau, Professor Küntscher Str. 8, 82418, Murnau, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: von Rüden
authors.affiliation: Institute of Biomechanics, Paracelsus Medical University, Salzburg, Austria.|Institute of Biomechanics, Trauma Centre Murnau, Professor Küntscher Str. 8, 82418, Murnau, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Greinwald
authors.affiliation: Institute of Biomechanics, Paracelsus Medical University, Salzburg, Austria.|Institute of Biomechanics, Trauma Centre Murnau, Professor Küntscher Str. 8, 82418, Murnau, Germany.|Department of Trauma Surgery, Trauma Centre Murnau, Professor Küntscher Str. 8, 82418, Murnau, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Hungerer
authors.affiliation: Institute of Biomechanics, Paracelsus Medical University, Salzburg, Austria.|Institute of Biomechanics, Trauma Centre Murnau, Professor Küntscher Str. 8, 82418, Murnau, Germany.|Department of Trauma Surgery, Trauma Centre Murnau, Professor Küntscher Str. 8, 82418, Murnau, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Pätzold
authors.affiliation: Institute of Biomechanics, Paracelsus Medical University, Salzburg, Austria.|Institute of Biomechanics, Trauma Centre Murnau, Professor Küntscher Str. 8, 82418, Murnau, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Augat
mesh_terms: D001696:Biomechanical Phenomena; D001860:Bone Plates / Q000009:adverse effects*; D001863:Bone Screws; D004551:Elbow Joint; D005593:Fracture Fixation, Internal / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D018460:Fractures, Comminuted / Q000601:surgery*; D006801:Humans; D006810:Humeral Fractures / Q000601:surgery*; D006811:Humerus / Q000601:surgery*; D011474:Prosthesis Design / Q000009:adverse effects; D011475:Prosthesis Failure / Q000209:etiology
keywords: Anatomical poly-axial plate; Distal humeral fracture; Failure mechanism; Fatigue limit; System stiffness