title: Periprosthetic supracondylar femoral fractures following knee arthroplasty: a biomechanical comparison of four methods of fixation.
abstract: OBJECTIVE
  The aim of this study was to determine the biomechanical properties of four fixation options for periprosthetic supracondylar femoral fractures.
  
  
  METHODS
  Fourth-generation composite femurs were implanted with a posterior-stabilizing femoral component of total knee arthroplasty. All femurs were osteotomized to produce a AO/OTA 33-A3 fracture pattern and four different constructs were tested: (1) non-locking plate; (2) polyaxial locking plate; (3) intramedullary fibular strut allograft with polyaxial locking plate; (4) retrograde intramedullary nail. The composite femurs underwent non-destructive tests to determine construct stiffness in axial and torsional cyclic loading. The final testing consisted of quasi-static axial loading until failure.
  
  
  RESULTS
  Under cyclic torsional loading, the retrograde intramedullary nail was less stiff than non-locking plate, polyaxial locking plate and intramedullary fibular strut allograft with polyaxial locking plate (p = 0.046). No differences were detected in cyclic axial loading between the different constructs. During quasi-static axial loading to failure, the intramedullary nail achieved the highest axial stiffness while the non-locking plate showed the lowest (p = 0.036).
  
  
  CONCLUSIONS
  The intramedullary fibular strut allograft with polyaxial locking plate did not prove to be significantly better to the polyaxial locking plate only in a periprosthetic distal femur fracture model.
authors: Mount Sinai Hospital, Division of Orthopaedic Surgery, University of Toronto, 600 University Avenue, Toronto, Ontario, M5G 1X5, Canada, tatu.makinen@hus.fi.
authors: Tatu J
authors: TJ
authors: Mäkinen
authors: Herman S
authors: HS
authors: Dhotar
authors: Simcha G
authors: SG
authors: Fichman
authors: Matthew J
authors: MJ
authors: Gunton
authors: Mitchell
authors: M
authors: Woodside
authors: Oleg
authors: O
authors: Safir
authors: David
authors: D
authors: Backstein
authors: Thomas L
authors: TL
authors: Willett
authors: Paul R T
authors: PR
authors: Kuzyk
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D001696:Biomechanical Phenomena; D001858:Bone Nails; D001860:Bone Plates; D005264:Femoral Fractures / Q000601:surgery*; D006801:Humans; D008953:Models, Anatomic; D057068:Periprosthetic Fractures / Q000601:surgery*