title: Long-term growth and alignment after occipitocervical and atlantoaxial fusion with rigid internal fixation in young children.
abstract: OBJECT The long-term consequences of atlantoaxial (AA) and occipitocervical (OC) fusion and instrumentation in young children are unknown. Anecdotal reports have raised concerns regarding altered growth and alignment of the cervical spine after surgical intervention. The purpose of this study was to determine the long-term effects of these surgeries on the growth and alignment of the maturing spine. METHODS A multiinstitutional retrospective chart review was conducted for patients less than or equal to 6 years of age who underwent OC or AA fusion with rigid instrumentation at 9 participating centers. All patients had at least 3 years of clinical and radiographic follow-up data and radiographically confirmed fusion. Preoperative, immediate postoperative, and most recent follow-up radiographs and/or CT scans were evaluated to assess changes in spinal growth and alignment. RESULTS Forty children (9 who underwent AA fusion and 31 who underwent OC fusion) were included in the study (mean follow-up duration 56 months). The mean vertical growth over the fused levels in the AA fusion patients represented 30% of the growth of the cervical spine (range 10%-50%). Three different vertical growth patterns of the fusion construct developed among the 31 OC fusion patients during the follow-up period: 1) 16 patients had substantial growth (13%-46% of the total growth of the cervical spine); 2) 9 patients had no meaningful growth; and 3) 6 patients, most of whom presented with a distracted atlantooccipital dislocation, had a decrease in the height of the fused levels (range 7-23 mm). Regarding spinal alignment, 85% (34/40) of the patients had good alignment at follow-up, with straight or mildly lordotic cervical curvatures. In 1 AA fusion patient (11%) and 5 OC fusion patients (16%), we observed new hyperlordosis (range 43°-62°). There were no cases of new kyphosis or swan-neck deformity, evidence of subaxial instability, or unintended subaxial fusion. No preoperative predictors of these growth patterns or alignment were evident. CONCLUSIONS These results demonstrate that most young children undergoing AA and OC fusion with rigid internal fixation continue to have good cervical alignment and continued growth within the fused levels during a prolonged follow-up period. However, some variability in vertical growth and alignment exists, highlighting the need to continue close long-term follow-up.
authors.affiliation: Department of Neurological Surgery, Columbia University, New York, New York;
authors.forename: Benjamin C
authors.initials: BC
authors.lastname: Kennedy
authors.affiliation: Department of Neurological Surgery, Columbia University, New York, New York;
authors.forename: Randy S
authors.initials: RS
authors.lastname: D'Amico
authors.affiliation: Department of Neurological Surgery, Columbia University, New York, New York;
authors.forename: Brett E
authors.initials: BE
authors.lastname: Youngerman
authors.affiliation: Department of Neurological Surgery, University of Pittsburgh, Pennsylvania;
authors.forename: Michael M
authors.initials: MM
authors.lastname: McDowell
authors.affiliation: Department of Neurological Surgery, University of Florida, Gainesville, Florida;
authors.forename: Kristopher G
authors.initials: KG
authors.lastname: Hooten
authors.affiliation: Department of Neurological Surgery, Wake Forest University Baptist Medical Center, Winston-Salem, North Carolina;
authors.forename: Daniel
authors.initials: D
authors.lastname: Couture
authors.affiliation: Division of Pediatric Neurosurgery, Texas Children's Hospital, Houston, Texas;
authors.forename: Andrew
authors.initials: A
authors.lastname: Jea
authors.affiliation: Department of Neurological Surgery, Ohio State University, Columbus, Ohio;
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Leonard
authors.affiliation: Department of Neurological Surgery, Medical College of Wisconsin/Children's Hospital of Wisconsin, Milwaukee, Wisconsin;
authors.forename: Sean M
authors.initials: SM
authors.lastname: Lew
authors.affiliation: Department of Neurological Surgery, University of Florida, Gainesville, Florida;
authors.forename: David W
authors.initials: DW
authors.lastname: Pincus
authors.affiliation: Department of Neurological Surgery, All Children's Hospital, St. Petersburg, Florida;
authors.forename: Luis
authors.initials: L
authors.lastname: Rodriguez
authors.affiliation: Department of Neurological Surgery, All Children's Hospital, St. Petersburg, Florida;
authors.forename: Gerald F
authors.initials: GF
authors.lastname: Tuite
authors.affiliation: Department of Neurological Surgery, Yale University School of Medicine, New Haven, Connecticut; and.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Diluna
authors.affiliation: Department of Neurological Surgery, University of Utah, Salt Lake City, Utah.
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Brockmeyer
authors.affiliation: Department of Neurological Surgery, Columbia University, New York, New York;
authors.forename: Richard C E
authors.initials: RC
authors.lastname: Anderson
mesh_terms: D001268:Atlanto-Axial Joint / Q000601:surgery; D002574:Cervical Vertebrae / Q000254:growth & development* / Q000601:surgery*; D002648:Child; D002675:Child, Preschool; D005500:Follow-Up Studies; D005593:Fracture Fixation, Internal / Q000009:adverse effects* / Q000379:methods; D006801:Humans; D007223:Infant; D009777:Occipital Bone / Q000601:surgery; D012189:Retrospective Studies; D013121:Spinal Curvatures / Q000209:etiology*; D013123:Spinal Fusion / Q000379:methods*; D016896:Treatment Outcome
keywords: AA = atlantoaxial; OC = occipitocervical; atlantoaxial; craniocervical; fixation; fusion; occipitocervical; spine