title: Selection of a rigid internal fixation construct for stabilization at the craniovertebral junction in pediatric patients.
abstract: OBJECTIVE
  Atlantoaxial and occipitocervical instability in children have traditionally been treated with posterior bone and wire fusion and external halo orthoses. Recently, successful outcomes have been achieved using rigid internal fixation, particularly C1-2 transarticular screws. The authors describe flow diagrams created to help clinicians determine which method of internal fixation to use in complex anatomical circumstances when bilateral transarticular screw placement is not possible.
  
  
  METHODS
  The records of children who underwent either atlantoaxial or occipitocervical fixation with rigid internal fixation over an 11-year period were retrospectively reviewed to define flow diagrams used to determine treatment protocols.
  
  
  RESULTS
  Among the 95 patients identified who underwent atlantoaxial or occipitocervical fixation, the craniocervical anatomy in 25 patients (six atlantoaxial and 19 occipitocervical fixations [26%]) required alternative methods of internal fixation. Types of screw fixation included loop or rod constructs anchored by combinations of C1-2 transarticular screws (15 constructs), C-1 lateral mass screws (11), C-2 pars screws (24), C-2 translaminar screws (one), and subaxial lateral mass screws (six). The mean age of the patients (15 boys and 10 girls) was 9.8 years (range 1.3-17 years). All 22 patients with greater than 3-month follow-up duration achieved solid bone fusion and maintained stable constructs on radiographic studies. Clinical improvement was seen in all patients who had preoperative symptoms.
  
  
  CONCLUSIONS
  Novel flow diagrams are suggested to help guide selection of rigid internal fixation constructs when performing pediatric C1-2 and occipitocervical stabilizations. Use of these flow diagrams has led to successful fusion in 25 pediatric patients with difficult anatomy requiring less common constructs.
authors.affiliation: Department of Neurosurgery, Children's Hospital of New York, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA. rca24@columbia.edu
authors.forename: Richard C E
authors.initials: RC
authors.lastname: Anderson
authors.forename: Brian T
authors.initials: BT
authors.lastname: Ragel
authors.forename: J
authors.initials: J
authors.lastname: Mocco
authors.forename: Leif-Erik
authors.initials: LE
authors.lastname: Bohman
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Brockmeyer
mesh_terms: D000293:Adolescent; D001268:Atlanto-Axial Joint / Q000473:pathology / Q000601:surgery*; D001269:Atlanto-Occipital Joint / Q000473:pathology / Q000601:surgery*; D001863:Bone Screws; D002574:Cervical Vertebrae / Q000473:pathology / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D003663:Decision Trees; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D007593:Joint Instability / Q000175:diagnosis / Q000209:etiology / Q000601:surgery*; D008297:Male; D011183:Postoperative Complications / Q000175:diagnosis*; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000379:methods*; D014057:Tomography, X-Ray Computed