Table 2.
I. Cellularity of the annulus fibrosus |
Grade |
Fibroblasts comprise more than 75 % of cells |
Neither fibroblasts nor chondrocytes comprise more than 75 % of cells |
Chondrocytes comprise more than 75 % of cells |
II. Morphology of the annulus fibrosus |
Grade |
Well-organized collagen lamellae without ruptures or serpentine |
Inward bulging, ruptured or serpentine fibers in less than one-third of the anulus |
Inward bulging, ruptured or serpentine fibers in more than one-third of the anulus |
III. Border between the annulus fibrosus and nucleus pulposus |
Grade |
Normal, without any interruption |
Minimal interruption |
Moderate or severe interruption |
IV. Cellularity of the nucleus pulposus |
Grade |
Normal cellularity with stellar-shaped nuclear cells evenly distributed throughout the nucleus |
Slight decrease in the no. of cells with some clustering |
Moderate or severe decrease (>50 %) in the number of cells with all the remaining cells clustered and separated by dense area of proteoglycans |
V. Morphology of the nucleus pulposus |
Grade |
Round, comprising at least half of the disc area in midsagittal sections |
Round or irregularly shaped, comprising less than one quarter to half of the disc area in midsagittal sections |
Irregularly shaped, comprising less than one quarter of the disc area in midsagittal sections |
The scale is based on 5 categories of degenerative change, with scores ranging from 5 points (1 in each category) for a normal disc to 15 points (3 in each category) for a severely degenerated disc