The intervertebral discs are cylindrical, fibrocartilaginous, articulating structures connecting the vertebral bodies, and it can be divided microscopically into an outer annulus fibrosus surrounding a centrally located nucleus pulposus.
Cervical disc degeneration and protrusion were prospectively measured using magnetic resonance imaging in 1211 relatively healthy volunteers. These included at least 100 males and 100 females in each decade of life between the 20s and the 70s. Cervical disc degeneration was defined according to the modified Pfirrmann classification system, and the amount of disc protrusion was evaluated using the anteroposterior diameter of disc protrusion on sagittal MR image.
- Mild disc degeneration was very common, including 98.0% of both sexes in their 20s.
- The severity of cervical disc degeneration significantly increased with age in both sexes at every level.
- The disc degeneration predominantly occurred at C5-C6 and C6-C7.
Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan