title: Equivalence of fusion rates after rigid internal fixation of the occiput to C-2 with or without C-1 instrumentation.
abstract: OBJECTIVE
  The object of this study was to assess a multiinstitutional experience with pediatric occipitocervical constructs to determine whether a difference exists between the fusion and complication rates of constructs with or without direct C-1 instrumentation.
  
  
  METHODS
  Seventy-seven cases of occiput-C2 instrumentation and fusion, performed at 9 children's hospitals, were retrospectively analyzed. Entry criteria included atlantooccipital instability with or without atlantoaxial instability. Any case involving subaxial instability was excluded. Constructs were divided into 3 groups based on the characteristics of the anchoring spinal instrumentation: Group 1, C-2 instrumentation; Group 2, C-1 and C-2 instrumentation without transarticular screw (TAS) placement; and Group 3, any TAS placement. Groups were compared based on rates of fusion and perioperative complications.
  
  
  RESULTS
  Group 1 consisted of 16 patients (20.8%) and had a 100% rate of radiographically demonstrated fusion. Group 2 included 22 patients (28.6%), and a 100% fusion rate was achieved, although 2 cases were lost to follow-up before documented fusion. Group 3 included 39 patients (50.6%) and demonstrated a 100% radiographic fusion rate. Complication rates were 12.5, 13.7, and 5.1%, respectively. There were 3 vertebral artery injuries, 1 (4.5%) in Group 2 and 2 (5.1%) in Group 3.
  
  
  CONCLUSIONS
  High fusion rates and low complication rates were achieved with each configuration examined. There was no difference in fusion rates between the group without (Group 1) and those with (Groups 2 and 3) C-1 instrumentation. These findings indicated that in the pediatric population, excellent occipitocervical fusion rates can be accomplished without directly instrumenting C-1.
authors.affiliation: Department of Neurosurgery, College of Physicians and Surgeons, Columbia University, New York, New York 10032, USA. tch12@columbia.edu
authors.forename: Todd C
authors.initials: TC
authors.lastname: Hankinson
authors.forename: Anthony M
authors.initials: AM
authors.lastname: Avellino
authors.forename: David
authors.initials: D
authors.lastname: Harter
authors.forename: Andrew
authors.initials: A
authors.lastname: Jea
authors.forename: Sean
authors.initials: S
authors.lastname: Lew
authors.forename: David
authors.initials: D
authors.lastname: Pincus
authors.forename: Mark R
authors.initials: MR
authors.lastname: Proctor
authors.forename: Luis
authors.initials: L
authors.lastname: Rodriguez
authors.forename: David
authors.initials: D
authors.lastname: Sacco
authors.forename: Theodore
authors.initials: T
authors.lastname: Spinks
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Brockmeyer
authors.forename: Richard C E
authors.initials: RC
authors.lastname: Anderson
mesh_terms: D000293:Adolescent; D001268:Atlanto-Axial Joint / Q000000981:diagnostic imaging / Q000601:surgery; D001368:Axis, Cervical Vertebra / Q000000981:diagnostic imaging / Q000601:surgery*; D001270:Cervical Atlas / Q000000981:diagnostic imaging / Q000601:surgery*; D002648:Child; D002675:Child, Preschool; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D016268:Internal Fixators; D007593:Joint Instability / Q000000981:diagnostic imaging / Q000601:surgery*; D009777:Occipital Bone / Q000000981:diagnostic imaging / Q000601:surgery*; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000295:instrumentation* / Q000379:methods*; D014057:Tomography, X-Ray Computed