Table 1 Radiological Classification of Migrated Disc Herniation [22]
Zone | Direction | Range of Distance |
|---|---|---|
Zone 1 | Far upward | From the inferior margin of the upper pedicle to 3 mm below the inferior margin of the upper pedicle |
Zone 2 | Near upward | From 3 mm below the inferior margin of the upper pedicle to the inferior margin of the upper vertebral body |
Zone 3 | Near downward | From the superior margin of the lower vertebral body to the center of the lower pedicle |
Zone 4 | Far downward | From the center to the inferior margin of the lower pedicle |