Table 1.

Histologic rating scale (total: 6‐18 points)

Annulus organization

1. Normal

2. Disrupted pattern <30%

3. Disrupted pattern >30%

Cartilage endplate

1. Normal

2. Minimally interrupted

3. Moderate/severe interruption

Cellularity of nucleus

1. Normal: notochordal cells distributed throughout matrix

2. Moderate decrease in cellularity

3. Severe decrease in cellularity

Matrix structure in nucleus

1. Cells distributed individually in lacey matrix or small clumps of notochordal cells in amorphous matrix

2. Large clumps of cells in amorphous matrix

3. Amorphous matrix with few or no clumps of cells

Size and shape of nucleus

1. Normal: large oval

2. Nucleus reduced in size <50%

3. Nucleus reduced>50%

Cellular infiltrate a

1. Absent

2. Some

3. Extensive

^aRefers to infiltration of immune cells during the inflammatory reaction to disc injury.