Table I.
Demographics, clinical scores, blood analyses and Ktrans values in subjects with metal-on-metal (MoM) bearing compared with metal-on-polyethylene (MoP) bearing, divided by gender
| Parameter |
MoM |
MoP |
||||
|---|---|---|---|---|---|---|
| Hips (patients) | Total8 (8) | Men5 (5) | Women3 (3) | Total8 (8) | Men2 (2) | Women6 (6) |
| Ktrans (min−1) | 0.046 (0.018) (0.025 to 0.071) | 0.034 (0.005) (0.025 to 0.037)† | 0.067 (0.005) (0.062 to 0.071) | 0.051 (0.007) (0.041 to 0.061) | 0.046 (0.002) (0.040 to 0.047) | 0.053 (0.008) (0.041 to 0.061) |
| Age (yrs) | 64.5 (6.2) (55 to 72) | 65.6 (6.3) (55 to 72) | 62.7 (6.8) (55 to 68) | 65.3 (5.3) (56 to 74) | 63.0 (1.4) (62 to 64) | 66.0 (6.0) (56 to 74) |
| BMI (kg/m2) | 29.1 (4.2) (25.0 to 34.4) | 29.7 (5.3) (25.0 to 34.4) | 28.3 (3.0) (25.8 to 31.6) | 27.7 (5.8) (23.3 to 37.9) | 24.6 (1.3) (23.7 to 25.5) | 29.0 (6.6) (23.3 to 37.9) |
| Baseline WOMAC | 54.7 (23.9) (11.3 to 87.9) | 55.4 (15.5) (37.3 to 78.0) | 53.6 (38.9) (11.3 to 87.9) | 49.2 (14.6) (26.3 to 70.3) | 40.6 (0.6) (40.2 to 41.0) | 52.1 (16.1) (26.3 to 70.3) |
| Baseline UCLA | 3.7 (2.0) (2 to 7) | 3.0 (1.4) (2 to 5) | 4.7 (2.5) (2 to 7) | 4.6 (2.5) (3 to 6) | 4.5 (2.1) (3 to 6) | 4.7 (1.5) (3 to 6) |
| Follow-up WOMAC | 91.8 (9.5) (78.1 to 100) | 88.2 (10.5) (78.1 to 100) | 97.9 (2.8) (94.8 to 100) | 86.0 (13.9) (60.0 to 100) | 89.1 (0.7) (88.5 to 89.6) | 85.0 (16.3) (60.0 to 100) |
| Follow-up UCLA | 7.1 (0.8) (6 to 8) | 7.2 (0.8) (6 to 8) | 7.0 (1.0) (6 to 8) | 6.6 (1.2) (5 to 8) | 7.5 (0.7) (6 to 8) | 6.3 (1.2) (5 to 8) |
| Titanium serum concentration (mg/ml) | 2.9 (3.1) (1.1 to 7.4) | 1.4 (0.4) (1.1 to 1.8)† | 7.4 | 2.7 (0.6) (1.7 to 3.4) | 2.95 (0.32) (2.73 to 3.18) | 2.55 (0.69) (1.76 to 3.40) |
| Chromium serum concentration (mg/ml) | 1.9 (1.2) (1.0 to 4.4)* | 2.0 (1.6) (1.0 to 4.4) | 1.7 (0.8) (1.0 to 2.5) | 0.4 (0.4) (0.1 to 1.0) | 0.24 (0.06) (0.19 to 0.28) | 0.44 (0.45) (0.06 to 1.21) |
| Cobalt serum concentration (mg/ml) | 3.6 (2.6) (0.8 to 8.4)* | 4.5 (2.9) (1.4 to 8.4) | 2.3 (1.9) (0.8 to 4.4) | 0.3 (0.1) (0.2 to 0.5) | 0.29 (0.11) (0.22 to 0.37) | 0.27 (0.12) (0.17 to 0.47) |
*
Significant difference between MoM and MoP bearing
†
Significant difference between gender with MoM bearing
Values of continuous parameters are expressed as mean and standard deviation with range in parentheses; BMI, body mass index; WOMAC, Western Ontario McMasters Universities Osteoarthritis index; UCLA, University of California, Los Angeles