title: Preliminary testing of a novel bilateral plating technique for treating periprosthetic fractures of the distal femur.
abstract: BACKGROUND
  Current stabilization methods for periprosthetic fractures of the distal femur are inadequate in achieving fracture fixation, with complication rates as high as 29%. A major contributor to poor outcomes is that these methods rely only on screw purchase in the bone to maintain fracture reduction. We designed, manufactured and evaluated a novel plating method that utilizes the femoral prosthesis to enhance stability for treatment of distal femoral periprosthetic fractures.
  
  
  METHODS
  Medial and lateral plates were designed and manufactured based on geometry of a synthetic femur and femoral prosthesis. The two plates were linked via a compression screw and a small tab on each plate that inserted into pre-existing slots on the prosthesis. Mechanical tests (500N compression or 250N anterior directed cantilever bending), were performed on synthetic femurs with simple transverse fractures (3mm gap) just superior to the distal femoral prosthesis that were stabilized using either the prototype plates or a single lateral plate. Translational movements of the fracture site during loading were measured using 3D motion tracking.
  
  
  RESULTS
  With the single lateral plate, the distal fragment experienced a resultant displacement of 0.40mm under cantilever bending and 0.61mm under compression (13% and 20% respectively of fracture gap width). With the bilateral plates, fracture gap motion was significantly reduced to 0.13mm under bending and compression (4.3% of the fracture gap).
  
  
  CONCLUSIONS
  Our results indicate that a bilateral plating method is capable of improving stabilization of periprosthetic fractures compared to the traditional lateral plating technique.
authors.affiliation: Department of Mechanical Engineering, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Aaron
authors.initials: A
authors.lastname: Muizelaar
authors.affiliation: Department of Surgery, Division of Orthopaedics, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Mitchell J
authors.initials: MJ
authors.lastname: Winemaker
authors.affiliation: Department of Mechanical Engineering, McMaster University, Hamilton, Ontario, Canada; McMaster School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Cheryl E
authors.initials: CE
authors.lastname: Quenneville
authors.affiliation: Department of Mechanical Engineering, McMaster University, Hamilton, Ontario, Canada; McMaster School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada. Electronic address: wohlg@mcmaster.ca.
authors.forename: Gregory R
authors.initials: GR
authors.lastname: Wohl
mesh_terms: D001860:Bone Plates; D001863:Bone Screws; D005264:Femoral Fractures / Q000601:surgery*; D005593:Fracture Fixation, Internal / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D057068:Periprosthetic Fractures / Q000601:surgery*
keywords: Bending; Bilateral plates; Compression; Distal femur; Fracture displacement; Lateral locking plate; Periprosthetic fracture