title: Preoperative planning simulator for spinal deformity surgeries.
abstract: METHODS
  Proof of concept of a spine surgery simulator (S3) for the assessment of scoliosis instrumentation configuration strategies.
  
  
  OBJECTIVE
  To develop and assess a surgeon-friendly spine surgery simulator that predicts the correction of a scoliotic spine as a function of the patient characteristics and instrumentation variables.
  
  
  BACKGROUND
  There is currently no clinical tool sufficiently user-friendly, reliable and refined for the preoperative planning and prediction of correction using different instrumentation configurations.
  
  
  METHODS
  A kinetic model using flexible mechanisms has been developed to represent patient-specific spine geometry and flexibility, and to simulate individual substeps of correction with an instrumentation system. The surgeon-friendly simulator interface allows interactive specification of the instrumentation components, surgical correction maneuvers and display of simulation results.
  
  
  RESULTS
  The simulations of spinal instrumentation procedures of 10 scoliotic cases agreed well with postoperative results and the expected behavior of the instrumented spine (average Cobb angle differences of 3.5 degrees to 4.6 degrees in the frontal plane and of 3.6 degrees to 4.7 degrees in the sagittal plane). Forces generated at the implant-vertebra link were mostly below reported pull-out values, with more important values at the extremities of the instrumentation.
  
  
  CONCLUSIONS
  The spine surgery simulator S3 has proven its technical feasibility and clinical relevance to assist in the preoperative planning of instrumentation strategies for the correction of scoliotic deformities.
authors.affiliation: Ecole Polytechnique de Montréal, Department of Mechanical Engineering, Montreal, Quebec H3C 3A7, Canada. carl-eric.aubin@polymtl.ca
authors.forename: C E
authors.initials: CE
authors.lastname: Aubin
authors.forename: H
authors.initials: H
authors.lastname: Labelle
authors.forename: C
authors.initials: C
authors.lastname: Chevrefils
authors.forename: G
authors.initials: G
authors.lastname: Desroches
authors.forename: J
authors.initials: J
authors.lastname: Clin
authors.forename: A Boivin M
authors.initials: AB
authors.lastname: Eng
mesh_terms: D001696:Biomechanical Phenomena; D003198:Computer Simulation; D006801:Humans; D016268:Internal Fixators; D008953:Models, Anatomic; D011300:Preoperative Care / Q000379:methods*; D012600:Scoliosis / Q000473:pathology / Q000601:surgery*; D012984:Software; D013131:Spine / Q000002:abnormalities / Q000601:surgery*; D016896:Treatment Outcome