title: Polyurethane real-size models used in planning complex spinal surgery.
abstract: METHODS
  The application of polyurethane real-size models for planning and performing complex spinal surgery is described.
  
  
  OBJECTIVE
  To determine the feasibility of using polyurethane real-size models to plan osteotomies, resections, and designs of custom-made spinal implants in complex spinal surgery.
  
  
  BACKGROUND
  In selected patients with complex spinal pathology, exact planning of the surgical procedure is not possible using current imaging methods. In these cases, real-size spinal models would be desirable to enhance pre- and perioperative planning by visual and tactile feedback, and to improve the production of custom-made spinal implants.
  
  
  METHODS
  A real-size spinal model of six patients was produced from hardened polyurethane foam on the basis of data from contiguous computer tomography slices. In two patients, the models were used to plan correction osteotomies and resections, with the assistance of image-guided surgery in one of the patients. In four patients, the models were used to plan tumor resections and to produce custom-made spinal implants.
  
  
  RESULTS
  In all the patients, the surgical procedure could be performed exactly according to the preplanned intervention. The polyurethane real-size models provided essential and additional information by direct visual and tactile feedback. They allowed in vitro testing of custom-made spinal implants with a perfect fit.
  
  
  CONCLUSIONS
  Real-size spinal models made from polyurethane foam can be used to provide excellent understanding of the complex spinal pathology in highly selected patients. These models allow complex spinal surgery with a more predictable outcome.
authors.affiliation: Department of Orthopaedic Surgery, University Hospital Vrije Universiteit, Amsterdam, The Netherlands. orthop@azvu.nl
authors.forename: M
authors.initials: M
authors.lastname: van Dijk
authors.forename: T H
authors.initials: TH
authors.lastname: Smit
authors.forename: T U
authors.initials: TU
authors.lastname: Jiya
authors.forename: P I
authors.initials: PI
authors.lastname: Wuisman
mesh_terms: D000293:Adolescent; D000328:Adult; D002675:Child, Preschool; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D008953:Models, Anatomic; D009985:Orthopedics / Q000379:methods*; D011140:Polyurethanes; D013131:Spine / Q000601:surgery*; D013514:Surgical Procedures, Operative / Q000379:methods*; D014057:Tomography, X-Ray Computed
chemical_list: D011140:Polyurethanes