title: Clinical outcome of posterior fixation of the C1 lateral mass and C2 pedicle by polyaxial screw and rod.
abstract: OBJECTIVE
  Because of atlantoaxial complex has a unique and complicated anatomy and instability of this complex is very dangerous. We investigated the clinical results of posterior C1-C2 fixation with a polyaxial screw-rod system.
  
  
  METHODS
  Between July 2001 and December 2007, the authors treated 17 patients suffering from atlantoaxial deformity and instability. Atlantoaxial fusion was employed in 9 patients with upper cervical fracture and dislocation, in 6 patients with atlantoaxial subluxation, in 1 patient with pure transverse ligament injury, and in 1 patient with basilar invagination. The mean age at the time of surgery was 40.4 years (range, 15-68 years).
  
  
  RESULTS
  Operative times ranged from 165 to 420 min (average 306 min), and the postoperative mean VAS score was 2.4. The mean follow-up period was 26 months. Solid fusion was achieved in 15 patients at the last follow up; no injury of the vertebral artery or spinal cord and no operative mortality occurred in these cases.
  
  
  CONCLUSIONS
  We suggest that posterior atlantoaxial fixation using the polyaxial screw-rod system is an effective and relatively safe technique. The navigation guidance system employed during the surgical procedure was helpful methods. Future studies of the feasibility of navigation system-guided surgical procedures will be required.
authors: Department of Neurosurgery, College of Medicine, Hallym University, Seoul, Republic of Korea.
authors: Sei Woong
authors: SW
authors: Jeon
authors: Je Hoon
authors: JH
authors: Jeong
authors: Gi Hoon
authors: GH
authors: Choi
authors: Seung Myung
authors: SM
authors: Moon
authors: Hyung Sik
authors: HS
authors: Hwang
authors: Sun Kil
authors: SK
authors: Choi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001268:Atlanto-Axial Joint / Q000002:abnormalities / Q000473:pathology / Q000601:surgery*; D001863:Bone Screws; D002533:Cerebral Angiography; D000013:Congenital Abnormalities; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016268:Internal Fixators; D007593:Joint Instability / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000379:methods*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000175:diagnosis / Q000453:epidemiology; D012189:Retrospective Studies; D012306:Risk; D013123:Spinal Fusion; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014711:Vertebral Artery / Q000293:injuries; D055815:Young Adult