title: Intraprosthetic screw fixation increases primary fixation stability in periprosthetic fractures of the femur - a biomechanical study.
abstract: BACKGROUND
  The purpose of this study was to develop a new fixation technique for the treatment of periprosthetic fractures using intraprosthetic screw fixation. The goal was to biomechanically evaluate the increase in primary fixation stability compared to unicortical locked-screw plating.
  
  
  METHODS
  A Vancouver C periprosthetic fracture was simulated in femur prosthesis constructs. Fixation was then performed with either unicortical locked-screw plating using the LISS-plate or with intraprosthetic screw fixation. Fixation stability was compared in an axial load-to-failure model.
  
  
  RESULTS
  The intraprosthetic fixation model was superior to the unicortical locked-screw fixation in all tested devices. The intraprosthetic fixation model required 11,807N±1596N for failure and the unicortical locked-screw plating required 7649N±653N (p=0.002).
  
  
  CONCLUSIONS
  Intraprosthetic screw anchorage with a special prosthesis drill enhances the primary stability in treating periprosthetic fractures by internal fixation.
authors.affiliation: Trauma Department Hannover Medical School, MHH, Germany. Electronic address: brand.stephan@mh-hannover.de.
authors.forename: Stephan
authors.initials: S
authors.lastname: Brand
authors.affiliation: Leibniz University Hannover, Institute of Materials Science, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Klotz
authors.affiliation: Leibniz University Hannover, Institute of Materials Science, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hassel
authors.affiliation: Trauma Department Hannover Medical School, MHH, Germany.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Petri
authors.affiliation: Department of Orthopaedic Surgery, Hannover Medical School, Germany.
authors.forename: Max
authors.initials: M
authors.lastname: Ettinger
authors.affiliation: Leibniz University Hannover, Institute of Materials Science, Germany.
authors.forename: Friedrich-Wilhelm
authors.initials: FW
authors.lastname: Bach
authors.affiliation: Trauma Department Hannover Medical School, MHH, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Krettek
authors.affiliation: Trauma Department Hannover Medical School, MHH, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Gösling
mesh_terms: D001696:Biomechanical Phenomena; D001863:Bone Screws; D005264:Femoral Fractures / Q000209:etiology / Q000601:surgery*; D005593:Fracture Fixation, Internal; D006622:Hip Prosthesis / Q000009:adverse effects; D008422:Materials Testing; D055595:Mechanical Phenomena; D057068:Periprosthetic Fractures / Q000209:etiology / Q000601:surgery*
keywords: Intraprosthetic screw fixation; LISS-plate; Locking-screw plating; Periprosthetic fracture