Table II.
Descriptive information by irradiation group.
| Variable | G1 | G2 | G3 |
|---|---|---|---|
| Radiation, Mrad | no radiation | < 5 | ≥ 5 |
| N | 12,449 | 232,562 | 45,759 |
| Sex (female), n (%) | 8,279 (66.5) | 154,886 (66.6) | 29,194 (63.8) |
| Mean age, yrs (SD) | 72.7 (9.4) | 73.8 (8.6) | 70.1 (10.7) |
| Age (years), n (%) | |||
| < 55 | 510 (4.1) | 5,349 (2.3) | 3,661 (8.0) |
| 55 to < 65 | 1,569 (12.6) | 24,884 (10.7) | 8,694 (19.0) |
| 65 to < 75 | 4,656 (37.4) | 86,280 (37.1) | 16,427 (35.9) |
| ≥ 75 | 5,714 (45.9) | 116,048 (49.9) | 16,977 (37.1) |
| Osteoarthritis indication, n (%) | 11,627 (93.4) | 217,213 (93.4) | 40,771 (89.1) |
| Acetabulum | |||
| Internal diameter size (mm), n (%) | |||
| 22.25 | 3,598 (28.9) | 29,768 (12.8) | 1,510 (3.3) |
| 26 | 523 (4.2) | 16,744 (7.2) | 0.0 (0) |
| 28 | 7,818 (62.8) | 155,584 (66.9) | 22,193 (48.5) |
| 32 | 510 (4.1) | 30,698 (13.2) | 18,624 (40.7) |
| 36 | 0.0 (0) | 0.0 (0) | 3,386 (7.4) |
| 40 | 0.0 (0) | 0.0 (0) | 46 (0.1) |
| Resin type = (1020), n (%) | 0.0 (0) | 14,186 (6.1) | 19,676 (43.0) |
| Terminal sterilization, n (%) | |||
| Gamma | 0.0 (0) | 232,562 (100) | 595 (1.3) |
| Ethylene oxide (EtO) | 12,449 (100) | 0.0 (0) | 2,059 (4.5) |
| Gas plasma | 0.0 (0) | 0.0 (0) | 43,105 (94.2) |
| Stabilization treatment (yes), n (%) | 0.0 (0) | 106,979 (46.0) | 45,759 (100) |
| Stabilization treatment typen (%) | |||
| None | 12,449 (100) | 125,583 (54.0) | 0.0 (0) |
| Heated below melting point | 0.0 | 106,979 (46.0) | 19,631 (42.9) |
| Heated above melting point | 0.0 | 0.0 (0) | 25,625 (56.0) |
| Vitamin E infused | 0.0 | 0.0 (0) | 503 (1.1) |
| Mean total radiation dose, Mrad (SD) | 0.0 (0.0) | 3.0 (0.1) | 7.0 (2.1) |
| Stem | |||
| Cementless stem, n (%) | 610 (4.9) | 10,465 (4.5) | 9,243 (20.2) |
| Head | |||
| Ceramic*, n (%) | 1,718 (13.8) | 20,465 (8.8) | 13,499 (29.5) |
| Metal, n (%) | 10,731 (86.2) | 212,097 (91.2) | 32,260 (70.5) |
| Outcomes | |||
| Mean person-time, yrs (SD) | 6.8 (3.0) | 5.6 (3.5) | 2.5 (1.7) |
| Maximum follow-up, yrs* | 13.3 | 13.3 | 7.8 |
| Outcome, n (%) | |||
| Not revised | 9,260 (74.4) | 182,757 (78.6) | 43,098 (94.2) |
| Revised | 309 (2.5) | 4,013 (1.7) | 386 (0.8) |
| Revised due to aseptic loosening (any component) | 132 | 1,376 | 68 |
| Revised due to aseptic loosening socket† | 110 | 1,107 | 41 |
| Revised due to aseptic loosening stem† | 59 | 665 | 35 |
| Expired | 2,880 (23.1) | 45,792 (19.7) | 2,275 (5.0) |
*
Includes 425 ceramicized metal (Oxinium) femoral heads.
†
Categories not mutually exclusive.