| Annulus fibrosus |
| Grade 1: normal pattern of fibrocartilage lamellae (U-shaped in posterior aspect and slightly convex in anterior aspect) without ruptured fibers and without serpentine appearance anywhere within annulus |
| Grade 2: ruptured or serpentine patterned fibers in less than 30% of annulus |
| Grade 3: ruptured or serpentine patterned fibers in more than 30% of annulus |
| Border between annulus fibrosus and nucleus pulposus |
| Grade 1: normal |
| Grade 2: minimally Interrupted |
| Grade 3: moderate/severe interruption |
| Cellularity of nucleus pulposus |
| Grade 1: normal cellularity with large vacuoles in gelatinous structure of matrix |
| Grade 2: slight decrease in number of cells and fewer vacuoles |
| Grade 3: moderate/severe decrease (> 50%) in number of cells and no vacuoles |
| Matrix of nucleus pulposus |
| Grade 1: normal gelatinous appearance |
| Grade 2: slight condensation of extracellular matrix |
| Grade 3: moderate/severe condensation of extracellular matrix |
