Grisel’s Syndrome in Children: Two Case Reports and Systematic Review of the Literature

Table 1

Fielding–Hawkins classification.

Type 1	Rotation of the atlas on the axis without displacement, or with anterior displacement ≤3 mm
Type 2	Rotatory fixation with anterior displacement of the atlas 3–5 mm
Type 3	Rotatory fixation with anterior displacement of the atlas ≥5 mm
Type 4	Rotatory fixation with posterior displacement (extremely rare condition)