title: Biomechanical Comparison of Locking Compression Plate versus Positive Profile Pins and Polymethylmethacrylate for Stabilization of the Canine Lumbar Vertebrae.
abstract: OBJECTIVE
  To compare the stiffness, angular deformation, and mode of failure of lumbar vertebral column constructs stabilized with bilateral pins and polymethylmethacrylate (Pin-PMMA) or with a unilateral (left) locking compression plate (LCP) with monocortical screws.
  
  
  METHODS
  Ex vivo biomechanical, non-randomized.
  
  
  METHODS
  Cadaveric canine thoracolumbar specimens (n=16).
  
  
  METHODS
  Thoracolumbar (T13-L3) vertebral specimens had the L1-L2 vertebral motion unit stabilized with either Pin-PMMA or LCP. Stiffness in flexion, extension, and right and left lateral bending after nondestructive testing were compared between intact (pretreated) specimens and Pin-PMMA, and LCP constructs. The Pin-PMMA and LCP constructs were then tested to failure in flexion and left lateral bending.
  
  
  RESULTS
  Both the Pin-PMMA and LCP constructs had reduced range of motion at the stabilized L1-L2 vertebral motion unit compared to intact specimens. The Pin-PMMA constructs had less range of motion for the flexion elastic zone than LCP constructs. The Pin-PMMA constructs were stiffer than intact specimens in flexion, extension, and lateral bending, and stiffer than LCP constructs in flexion and left lateral bending. The Pin-PMMA constructs had less angular deformation at construct yield and lower residual deformation at L1-L2 than LCP constructs after destructive testing to failure in flexion. The Pin-PMMA constructs were stiffer, stronger, and had less deformation at yield than LCP constructs after destructive testing to failure in lateral bending. Most constructs failed distant to the implant and fixation site.
  
  
  CONCLUSIONS
  Pin-PMMA constructs had greater lumbar vertebral stiffness and reduced ROM than LCP constructs; however, both Pin-PMMA and LCP constructs were stronger than intact specimens.
authors.affiliation: Department of Surgical and Radiological Sciences.
authors.forename: Beverly K
authors.initials: BK
authors.lastname: Sturges
authors.affiliation: Department of Surgical and Radiological Sciences.
authors.forename: Amy S
authors.initials: AS
authors.lastname: Kapatkin
authors.affiliation: JD Wheat Veterinary Orthopedic Research Laboratory.
authors.forename: Tanya C
authors.initials: TC
authors.lastname: Garcia
authors.affiliation: William R. Pritchard Veterinary Teaching Hospital, School of Veterinary Medicine, University of California-Davis, Davis, California.
authors.forename: Cona
authors.initials: C
authors.lastname: Anwer
authors.affiliation: JD Wheat Veterinary Orthopedic Research Laboratory.
authors.forename: Shimpei
authors.initials: S
authors.lastname: Fukuda
authors.affiliation: JD Wheat Veterinary Orthopedic Research Laboratory.
authors.forename: Peta L
authors.initials: PL
authors.lastname: Hitchens
authors.affiliation: JD Wheat Veterinary Orthopedic Research Laboratory.
authors.forename: Tristan
authors.initials: T
authors.lastname: Wisner
authors.affiliation: Department of Surgical and Radiological Sciences.
authors.forename: Kei
authors.initials: K
authors.lastname: Hayashi
authors.affiliation: JD Wheat Veterinary Orthopedic Research Laboratory.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Stover
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D001858:Bone Nails / Q000662:veterinary*; D001860:Bone Plates / Q000662:veterinary*; D004285:Dogs / Q000293:injuries* / Q000601:surgery; D008159:Lumbar Vertebrae / Q000293:injuries* / Q000601:surgery; D019904:Polymethyl Methacrylate; D016059:Range of Motion, Articular; D016103:Spinal Fractures / Q000601:surgery / Q000662:veterinary*
chemical_list: D019904:Polymethyl Methacrylate