title: Posterior occipitocervical reconstruction using cervical pedicle screws and plate-rod systems.
abstract: METHODS
  This retrospective study was conducted to analyze the clinical results in 26 patients with lesions at the craniocervical junction that had been treated by occipitocervical reconstruction using pedicle screws in the cervical spine and occipitocervical rod systems.
  
  
  OBJECTIVE
  To evaluate the effectiveness of pedicle screw fixation in occipitocervical reconstructive surgery and to introduce surgical techniques.
  
  
  BACKGROUND
  Many methods of occipitocervical reconstruction have been reported, but there have been no reports of occipitocervical reconstruction using pedicle screws and occipitocervical rod systems for reduction and fixation.
  
  
  METHODS
  Twenty-six patients with lesions at the craniocervical junction underwent reconstructive surgery using pedicle screws in the cervical spine and occipitocervical rod systems. The occipitocervical lesions were atlantoaxial subluxation associated with basilar invagination, which was caused by rheumatoid arthritis in 19 patients and other disorders in 7. The lowest cervical vertebra of fusion in 16 patients was C2, and the remaining 10 patients underwent fusion downward from C3 to C7. Flexion deformity of the occipitoatlantoaxial complex was corrected by application of extensional force, and upward migration of the odontoid process was reduced by application of combined force of extension and distraction between the occiput and the cervical pedicle screws.
  
  
  RESULTS
  Solid fusion was achieved in all patients except two with metastatic vertebral tumors who did not receive bone graft for fusion. Correction of malalignment at the craniocervical junction was adequate, and postoperative magnetic resonance imaging showed improvement of anterior compression of the medulla oblongata. There were no neurovascular complications of cervical pedicle screws.
  
  
  CONCLUSIONS
  Occipitocervical reconstruction by the combination of cervical pedicle screws and occipitocervical rod systems provided the high fusion rate and sufficient correction of malalignment in the occipitoatlantoaxial region. Results of this study showed the effectiveness of cervical pedicle screw as a fixation anchor for occipitocervical reconstruction.
authors.affiliation: Department of Orthopaedic Surgery, Hokkaido University, School of Medicine, Sapporo, Japan. abumi@med.hokudai.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Abumi
authors.forename: T
authors.initials: T
authors.lastname: Takada
authors.forename: Y
authors.initials: Y
authors.lastname: Shono
authors.forename: K
authors.initials: K
authors.lastname: Kaneda
authors.forename: M
authors.initials: M
authors.lastname: Fujiya
mesh_terms: D000328:Adult; D001268:Atlanto-Axial Joint; D001858:Bone Nails; D001860:Bone Plates; D001863:Bone Screws; D002574:Cervical Vertebrae / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009777:Occipital Bone / Q000601:surgery*; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000379:methods*; D016896:Treatment Outcome