Variable | Stable implant (N = 121) | Unstable cup (N = 32) | P |
---|---|---|---|
Age at surgery (yrs.) | 45.6 ± 7.1 | 47.8 ± 5.8 | 0.102a |
 | 45.4 (25.1-64.5) | 48.3 (37.6-56.7) |  |
Height (cm) | 165.7 ± 8.7 | 165.4 ± 9.5 | 0.864a |
 | 165 (150-195) | 165 (149-187) |  |
Weight (kg) | 75.1 ± 14.3 | 75.2 ± 14.8 | 0.918b |
 | 73 (42-114) | 73 (50-105) |  |
Cup size (mm) | 50.2 ± 3.7 | 50.5 ± 4.1 | 0.830b |
 | 50 (46-60) | 49 (46-60) |  |
PE liner thickness (mm) | 7.0 ± 1.9 | 7.2 ± 2.0 | 0.805b |
 | 6.9 (2.8-11.9) | 6.4 (4.9-11.9) |  |
Abduction angle of the cup (°) | 46.0 ± 8.2 | 43.0 ± 6.3 | 0.073b |
 | 46 (28-72) | 43 (28-54) |  |
Time to revision surgery (yrs.) | 5.7 ± 1.8 | 6.9 ± 1.8 | 0.002 a |
 | 5.7 (2.0-10.4) | 6.9 (3.7-10.5) |  |
Linear wear rate (mm/yrs.) | 0.42 ± 0.38 | 0.39 ± 0.32 | 0.764b |
 | 0.35 (0.0-2.28) | 0.31 (0.0-1.32) |  |
Volumetric wear rate (mm3/yrs.) | 157 ± 139 | 144 ± 119 | 0.774b |
 | 127 (0-815) | 107 (12-467) |  |