title: Biomechanical analysis of stacked plating techniques to stabilize distal radial fractures in small dogs.
abstract: OBJECTIVE
  To evaluate the fatigue life of partially stacked and fully stacked (1.5/2.0 and 2.0/2.7 mm) veterinary cuttable plates (VCP) in a fracture gap model of the distal aspect of the radius.
  
  
  METHODS
  In vitro biomechanical study.
  
  
  METHODS
  Constructs (n=4/group) were assembled for each of 8 groups using 8-hole plates (1.5/2.0 and 2.0/2.7 mm VCP) in the following configurations: unstacked; 2-hole stacked centered over the gap (COG); 4-hole stacked COG; and fully stacked. Plate(s) were secured to 2 separate polyvinylchloride pipe lengths, mounted to a mechanical testing system with a custom jig, and were loaded in axial compression for 10(6) cycles at 10 Hz or until failure at 6-60 N for the 1.5/2.0 mm VCP and 10-100 N for the 2.0/2.7 mm VCP. Differences in number of cycles, stiffness, and failure mode were recorded.
  
  
  RESULTS
  All construct failures occurred through a screw hole adjacent to the gap. Fully stacked and 4-hole stacked 1.5/2.0 and 2.0/2.7 mm VCP withstood 10(6) cycles. Fatigue life and stiffness of the 1.5/2.0 or 2.0/2.7 mm unstacked constructs were significantly less than the other constructs. Differences were identified in stiffness among the 1.5/2.0 mm stacked constructs and in fatigue life among the 2.0/2.7 mm VCP stacked constructs.
  
  
  CONCLUSIONS
  Four-hole partially stacked VCP (either 1.5/2.0 or 2.0/2.7 mm) have comparable mechanical properties to fully stacked VCP.
  
  
  CONCLUSIONS
  Partial stacking of 2 holes of VCP on both sides of the fracture gap may provide sufficient strength for healing, but this premise must be tested in vivo.
authors.affiliation: Department of Veterinary Clinical Sciences, University of Minnesota, St. Paul, MN 55108, USA.
authors.forename: Brian W
authors.initials: BW
authors.lastname: Rose
authors.forename: G Elizabeth
authors.initials: GE
authors.lastname: Pluhar
authors.forename: Roberto E
authors.initials: RE
authors.lastname: Novo
authors.forename: Scott
authors.initials: S
authors.lastname: Lunos
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D001860:Bone Plates / Q000662:veterinary*; D001863:Bone Screws / Q000662:veterinary; D004285:Dogs / Q000293:injuries* / Q000601:surgery; D011885:Radius Fractures / Q000601:surgery / Q000662:veterinary*; D016474:Weight-Bearing