title: Usefulness of 3-dimensional full-scale modeling for preoperative simulation of surgery in a patient with old unilateral cervical fracture-dislocation.
abstract: METHODS
  Case report.
  
  
  OBJECTIVE
  We describe the usefulness of 3-dimensional full-scale modeling for preoperative simulation of surgery in a patient with old cervical fracture-dislocation.
  
  
  BACKGROUND
  Many different surgical procedures have been used in the treatment of unilateral cervical fracture-dislocation. However, consistent protocols and procedures for the surgical correction of old fracture-dislocations associated with nerve root lesions have not been established.
  
  
  METHODS
  Two months after an automobile accident, a 50-year-old man developed symptoms of left C5 palsy. Four months after the accident, he was diagnosed with a fracture-dislocation at left C4-C5 facet with impingement of the left C5 root at the neural foramen. In addition, his left vertebral artery was completely occluded. Spontaneous bony fusion had progressed around the left facet and the anterior aspect of the vertebrae at C4-C5. Before surgery, a 3-dimensional full-scale model in the patient's cervical spine was made in order to simulate the planned surgical reconstruction.
  
  
  RESULTS
  Through this simulation, we were able to accurately evaluate the deformed bony structures around the fractured C4-C5 facet. During the actual surgery, all the planned procedures were successfully achieved, including anterior release, insertion of pedicle screws at left C4 and C5, unroofing of the left C5 root, reduction of the displaced facet with the pedicle screw-rod system, and spinal fusion at C4-C5. After surgery, the patient's left C5 palsy was dramatically relieved and the spinal fusion went on to successful healing.
  
  
  CONCLUSIONS
  The surgical simulation made possible by the 3-dimensional full-scale model appeared to simplify the surgical procedure and may enhance the safety of the complex spinal reconstruction.
authors: Department of Orthopaedic Surgery, Chiba University Graduate School of Medicine, Inohana, Chuo-ku, Chiba, Japan. masashiy@faculty.chiba-u.jp
authors: Masashi
authors: M
authors: Yamazaki
authors: Akihiko
authors: A
authors: Okawa
authors: Tsutomu
authors: T
authors: Akazawa
authors: Masao
authors: M
authors: Koda
mesh_terms: D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery*; D003198:Computer Simulation; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008875:Middle Aged; D008953:Models, Anatomic; D011300:Preoperative Care / Q000379:methods; D011859:Radiography; D016103:Spinal Fractures / Q000000981:diagnostic imaging / Q000601:surgery*