title: Vertebral osteoporosis: perfused animal cadaver model for testing new vertebroplastic agents.
abstract: METHODS
  Experimental study.
  
  
  OBJECTIVE
  It was aimed to establish a cadaver model to imitate osteoporotic perfused vertebral bone and to allow for transpedicular transfer of bone cement and various new materials into vertebrae. The model was perfused to simulate vertebroplasty in the presence of transvertebral blood flow.
  
  
  BACKGROUND
  The injection of bone cement into vertebrae bears the risk of irreversible discharge of material into the venous system of the spinal canal. The bovine cadaver model studied allows visual studies of material distribution in a vertebral bone, the potential spill-out of material, and quantification of washout and disintegration phenomena.
  
  
  METHODS
  Thoracic and lumbar vertebrae from 1-year-old calves were cut transversally into 5 mm slices, macerated, and decalcified. The softened bone slices were compressed between 2 transparent plastic discs. A standard vertebroplasty cannula (outer diameter 3.5 mm, inner diameter 2.5 mm) was inserted into the vertebral body via the pedicle to transfer the different vertebroplasty materials. Arterial blood flow was simulated by means of liquid irrigation via 2 needles in the ventral part of the vertebral body slice. Metal powder was mixed with the solution to indicate the blood flow in the bone. The model was evaluated with the vertebroplasty cement polymethylmethacrylate.
  
  
  RESULTS
  The model permitted visualization of the insertion and distribution of vertebroplasty materials. Liquid bone cement was effused into the spinal canal as in the clinical situation. Higher modulus cement acted in the same way as in clinical vertebroplasty. Rigid vertebroplasty agents led to trabecular fractures and stable mechanical interactions with the bone and eventually moved dorsal bone fragments into the spinal canal. Sedimentation of the metal powder indicated regions of perfusion.
  
  
  CONCLUSIONS
  The model simulated the clinical behavior of liquid and higher modulus vertebroplasty agents in the presence of blood flow. It enabled safe ex vivo testing of the mechanical and physical properties of alternative vertebroplasty materials under flow conditions.
authors.affiliation: Spine Center Baden, Mittelbaden Hospital, Baden-Baden, Germany. Hoell@klinikum-mittelbaden.de
authors.forename: Thomas
authors.initials: T
authors.lastname: Hoell
authors.forename: Gerald
authors.initials: G
authors.lastname: Huschak
authors.forename: Andre
authors.initials: A
authors.lastname: Beier
authors.forename: Hans-Juergen
authors.initials: HJ
authors.lastname: Holzhausen
authors.forename: Hans-Joerg
authors.initials: HJ
authors.lastname: Meisel
authors.forename: Frank
authors.initials: F
authors.lastname: Emmrich
mesh_terms: D000818:Animals; D001843:Bone Cements; D002417:Cattle; D004195:Disease Models, Animal; D058498:Kyphoplasty; D008159:Lumbar Vertebrae / Q000601:surgery*; D010024:Osteoporosis / Q000601:surgery*; D013904:Thoracic Vertebrae / Q000601:surgery*; D054854:Vertebroplasty
chemical_list: D001843:Bone Cements