Condyle-C1 interval (CCI)
The condyle-C1 interval (CCI) is the measurement of the interval between condyle and C1 at four equidistant points on the joint surface in sagittal and coronal reconstructions of computed tomography.
The CCI is reported to have a high lateral symmetry in children . Used with a cut-off of 4 mm, the CCI has a high diagnostic accuracy regarding atlanto-occipital dislocation in pediatric patients .
Despite this, many cases of atlanto-occipital injury can be missed using this criteria alone. In patients with a mecanism of trauma compatible with this type of injury, MRI evaluation is recommended to evaluate potential ligamentous injury .