Facet coverage in children on flexion lateral cervical radiographs.

STUDY DESIGN: This radiographic study was designed to attempt to develop standards of facet coverage (overlap) on lateral cervical radiographs during voluntary flexion. OBJECTIVE: To produce normative standards for minimum facet coverage in children. SUMMARY OF BACKGROUND DATA: Previous studies on normative standards of facet coverage have been performed only in adults. METHODS: Thirty-six children with minor trauma had lateral flexion-extension radiographs. A standard filming sequence was used in all. Facet joint overlap at each level was divided by the anteroposterior diameter of the upper adjacent cervical body at each level. RESULTS: On linear regression analysis, these ratios did not vary significantly with age at C2-C3 through C6-C7. Means and standard deviations were determined for C2-C7. CONCLUSIONS: These ratios may prove useful in evaluation of children with possible ligamentous injury.