| Age < 45 | Age 45-54 | Age 55-64 | Age 65+ |
---|---|---|---|---|
No degeneration | 16 (20%) | 7 (9%) | 4 (4%) | 4 (4%) |
Isolated anterior degeneration | 35 (44%) | 35 (44%) | 11 (12%) | 8 (7%) |
Combined anterior/posterior degeneration | 22 (28%) | 32 (40%) | 66 (72%) | 87 (80%) |
Isolated posterior degeneration | 7 (9%) | 6 (8%) | 11 (12%) | 10 (9%) |