Introduction: The authors assessed the rate of vertebral growth, curvature, and alignment for multilevel constructs in the cervical spine after occipitocervical fixation (OCF) in pediatric patients and compared these results with literature reports of growth in normal children.
Methods: The cervical spine radiographs and computed tomography images from 18 patients who underwent occipitocervical arthrodesis were assessed. Measurements were made from postoperative and last follow-up images available for 16 patients to determine cervical alignment (cervical spine alignment [CSA], C1-C7 sagittal vertical axis [SVA], and C2-C7 SVA) and curvature (cervical spine curvature [CSC] and C2-C7 lordosis angle). Seventeen patients had postoperative and last follow-up images available to measure vertebral body height (VBH), vertebral body width (VBW), and vertical growth (VG%, percent change from postoperative to follow-up). Results for cervical spine growth were compared with normal parameters of 456 patients previously reported in two studies.
Results: Ten patients were female and 8 were male. Constructs spanned O-C2 (n=2), O-C3 (n=7), and O-C4 (n=9). Mean age at surgery was 6.7 years (range, 7 months–12 years) and mean follow-up was 44.4 months (range, 24–101 months). Mean CSA increased by 1.8 ± 2.9 mm (p < 0.01). Mean C2-C7 SVA and C1-C7 SVA increased by 2.3 mm and 2.7 mm, respectively (p = 0.3). Mean CSC increased by -8.7° (p < 0.01) and C2-C7 lordosis by 2.6° (p = 0.5). The cumulative mean VG% of the instrumented levels (C2-C4) provided 51.5% of the total cervical growth (C2-C7). The annual vertical-growth rate for our patients was 4.4 mm/yr. The VBW growth from C2-C4 ranged from 13.9% to 16.6% (p < 0.001). The VBW of C2 in instrumented patients appeared to have a smaller diameter compared with normal patients, especially among those aged 5 to <10 and 10 to 15 years old, compensated by an increased diameter at the immediately inferior vertebral bodies. Cervical deformation, malalignment, or detrimental clinical status were not evident in any patients.
Conclusions: The craniovertebral junction and the upper cervical spine continue to present normal growth, curvature, and alignment parameters in children with OCF constructs as long as O-C4.
Patient Care: Provide neurosurgeons an clearer answer to the dilemma of whether the pediatric cervical spine suffers clinically and radiologically significant changes in long-term follow-ups after OC fusion.
Learning Objectives: Analyze clinical and radiographical data in pediatric patients ensuing OC fusion.