Levine and Effendi classification

The system of Effendi et al, as modified by Levine and others, is widely used in grading adult HF (not applicable to peds). Angulation is measured as the angle between the inferior endplates of C2 and C3. Anterior subluxation of C2 on C3 > 3 mm (Type II) is a surrogate marker for C2–3 disc disruption, which can be evaluated more directly with cervical MRI.

Effendi classification.