Table 1.
Number of patients (n) with metal-on-metal or metal-on-polyethylene prostheses stratified by age at operation and number of person-years at risk up to the end of 2005 by age at follow-up.
| Age (years) | Metal-on-metal prosthesis | Metal-on-polyethylene prosthesis | ||
|---|---|---|---|---|
| n | Person-years | n | Person-years | |
| 20 to 29 | 2 | 15.5 | 4 | 7.1 |
| 30 to 39 | 6 | 28.7 | 16 | 107.0 |
| 40 to 49 | 25 | 176.2 | 55 | 354.7 |
| 50 to 59 | 145 | 855.6 | 291 | 1800.0 |
| 60 to 69 | 278 | 2836.3 | 779 | 6694.5 |
| 70 to 79 | 113 | 3898.4 | 419 | 10848.2 |
| ≥ 80 | 10 | 2374.3 | 21 | 6595.5 |
| Total | 579 | 10185.1 | 1585 | 26406.9 |