Numericals in the right column are AF: annulus fibrosus; NP: nucleus pulposus; VB: vertebral bone; EP: cartilage endplate; MC: microcrack

Figure 4: Representative histologic slides. Top row; x4 Safranin-O stained slides, Middle row; x20 Safranin-O stained slides. Lower row; Alcian Blue-PAS photographed at 20x magnification.