title: Peri-implant failure in dual plating of the distal humerus-A biomechanical analysis with regard to screw and plate positioning.
abstract: OBJECTIVE
  The aim of this biomechanical study was to analyse the influence of plate and screw positioning on peri-implant failure in dual plate osteosynthesis. We hypothesized that screw positioning rather than plate configuration influences the risk of peri-implant fractures.
  
  
  METHODS
  Twenty macerated humerus specimens were available. 5 groups of 4 were built according to specimen size. Locking dual plates (Medartis, Switzerland) were randomly applied to the distal humerus of the specimens in 4 types of configuration: Bending forces were applied using a universal testing machine until peri-implant fracture occurred.
  
  
  RESULTS
  Mean failure loads for respective configuration types were as follows: P1: 428.7 (±84.2) N, A1: 410.0 (±54.7) N, A0: 297.8 (±48.3) N, P0: 261.0 (±65.0) N. Configurations with positioning of the most proximal screws at different levels (P1, A1) reached significantly higher failure loads when compared to screw placement at the same level (P0, A0) (0.01≤p≤0.03). Altering the plate configuration did not significantly influence failure loads (0.34≤p≤0.58).
  
  
  CONCLUSIONS
  The results of this study suggest that placement of the most proximal screws rather than the configuration of the plates is critical regarding the predetermined risk of peri-implant failure in dual plate osteosynthesis of the distal humerus. Varying levels of the outermost screws of corresponding double plates seem to be crucial to avoid complications related to the osteosynthesis.
authors: Center for Orthopedic and Trauma Surgery, University Medical Center, Cologne, Germany; Cologne Center for Musculoskeletal Biomechanics, Medical Faculty, University of Cologne, Cologne, Germany; Institute of Anatomy I, University of Cologne, Cologne, Germany. Electronic address: michael.hackl@uk-koeln.de.
authors: Michael
authors: M
authors: Hackl
authors: Center for Orthopedic and Trauma Surgery, University Medical Center, Cologne, Germany; Cologne Center for Musculoskeletal Biomechanics, Medical Faculty, University of Cologne, Cologne, Germany.
authors: Kilian
authors: K
authors: Wegmann
authors: Center for Orthopedic and Trauma Surgery, University Medical Center, Cologne, Germany.
authors: Soudad
authors: S
authors: Taibah
authors: Clinic for Shoulder Surgery, Bad Neustadt/Saale, Germany.
authors: Klaus Josef
authors: KJ
authors: Burkhart
authors: Cologne Center for Musculoskeletal Biomechanics, Medical Faculty, University of Cologne, Cologne, Germany; Institute of Anatomy II, University of Cologne, Cologne, Germany.
authors: Martin
authors: M
authors: Scaal
authors: Center for Orthopedic and Trauma Surgery, University Medical Center, Cologne, Germany; Cologne Center for Musculoskeletal Biomechanics, Medical Faculty, University of Cologne, Cologne, Germany.
authors: Lars Peter
authors: LP
authors: Müller
mesh_terms: D001696:Biomechanical Phenomena; D015519:Bone Density; D001860:Bone Plates; D001863:Bone Screws; D002102:Cadaver; D005594:Fracture Fixation, Intramedullary / Q000379:methods*; D006801:Humans; D008422:Materials Testing; D057068:Periprosthetic Fractures / Q000601:surgery*; D011475:Prosthesis Failure
keywords: Distal humerus; Double plating; Dual plating; Osteosynthesis; Peri-implant failure; Peri-implant fracture