Background: The developmental anatomy and biomechanics of the upper cervical spine are unique in children. Congenital osseous anomalies in this region may be associated with an increased risk for subsequent neurological compromise from instability and/or spinal cord encroachment. We performed a double-cohort study evaluating congenital osseous anomalies of the upper cervical spine in children who presented with one or more clinical problems, and we attempted to outline the risk of possible neurological compromise. Methods: We reviewed the medical records and imaging studies of all children seen and treated for osseous anomalies of the upper cervical spine at our institution between 1988 and 2003. Patients were divided into two cohorts on the basis of the presence or absence of associated syndromes. Parameters reviewed included demographic data, clinical presentation, and imaging features. All anomalies involving the central nervous system, the occipitocervical junction, and the upper cervical osseous canal were included. Complicating sequelae such as canal stenosis, segmental instability, and other anomalies of the central nervous system and spine were identified. Results: Sixty-eight consecutive children were identified. Twenty-one patients had an underlying described syndrome. There were 234 osseous anomalies (average, 3.4 per patient). Three or more anomalies were noted in 79% of the patients. There was no significant difference in the mean number of anomalies (p = 0.80) or in the frequency of any specific anomaly (p > 0.20 for all) between syndromic and nonsyndromic patients. The variety of clinical presentations included neck pain (twenty-six patients), neurological changes (twenty-one patients), and torticollis and/or stiffness (twenty-one patients). Twenty-three patients had more than one complaint. Six patients had isolated spinal instability, twenty-eight had isolated spinal cord encroachment, and six had a combination of both. Forty-four (65%) of the sixty-eight patients underwent surgical decompression and/or arthrodesis principally focused from the foramen magnum to the second cervical vertebra. Conclusions: As a result of these findings, we recommend a thorough evaluation and advanced imaging of the upper cervical spine in all children who present with symptoms related to the upper cervical spine, to identify associated anomalies and further define the nature of canal encroachment including any potential for neurologic compromise. Level of Evidence: Prognostic Level III. See Instructions to Authors for a complete description of levels of evidence.
