Table 3.
Patient demographics for the population studied, by bearing
| All patients | Metal-on-polyethylene (Reference) | Bearing Ceramic-on-polyethylene | Ceramic-on-ceramic | p-value a | |
|---|---|---|---|---|---|
| Number (%) | 4,596 | 2,171 (47.2) | 361 (7.9) | 2,064 (44.9) | |
| Patient factors | |||||
| Age, mean (SD) range | 66.0 (9.7) 25.2–95.1 | 70.8 (8.0) 31.0–95.1 | 64.6 (8.3) 39.0–87.2 | 61.1 (9.1) 25.2–91.5 | < 0.001 |
| Females, n (%) | 2,620 (57.0) | 1,259 (58.0) | 220 (60.9) | 1,141 (55.3) | 0.06 |
| ASA, n (%) | < 0.001 | ||||
| 1 | 804 (17.5) | 246 (11.3) | 64 (17.7) | 494 (23.9) | |
| 2 | 3,360 (73.1) | 1,673 (77.1) | 249 (69.0) | 1,438 (69.7) | |
| 3+ | 432 (9.4) | 252 (11.6) | 48 (13.3) | 132 (6.4) | |
| BMI (SD) range b | 29.0 (5.4) 15–65 | 28.7 (5.2) 15–56 | 29.3 (5.3) 18–54 | 29.2 (5.6) 18–65 | 0.09 |
| Comorbidities, n (%) | |||||
| Heart disease | 388 (8.4) | 233 (10.7) | 28 (7.8) | 127 (6.2) | < 0.001 |
| Stroke | 67 (1.5) | 42 (1.9) | 4 (1.1) | 21 (1.0) | 0.04 |
| Diabetes | 355 (7.7) | 201 (9.3) | 27 (7.5) | 127 (6.2) | 0.001 |
| Hypertension | 1,764 (38.4) | 960 (44.2) | 136 (37.7) | 668 (32.4) | < 0.001 |
| Circulation | 221 (4.8) | 132 (6.1) | 25 (6.9) | 64 (3.1) | < 0.001 |
| Lung | 270 (5.9) | 122 (5.6) | 21 (5.8) | 127 (6.2) | 0.8 |
| Depression | 309 (6.7) | 123 (5.7) | 25 (6.9) | 161 (7.8) | 0.02 |
| Preoperative general health | 0.001 | ||||
| Excellent | 265 (5.8) | 104 (4.8) | 20 (5.5) | 137 (6.6) | |
| Very good | 1,413 (30.7) | 649 (29.9) | 93 (25.8) | 669 (32.4) | |
| Good | 2,008 (43.7) | 1,004 (46.2) | 184 (51.0) | 819 (39.7) | |
| Fair | 781 (17.0) | 363 (16.7) | 53 (14.7) | 380 (18.4) | |
| Poor | 129 (2.9) | 51 (2.3) | 11 (3.0) | 59 (2.9) | |
| Preoperative disability | 2,229 (48.5) | 1,117 (51.5) | 192 (53.2) | 920 (44.6) | < 0.001 |
| Surgical factors | |||||
| Chemical VTE prophylaxis | < 0.001 | ||||
| LMWH only | 2,583 (56.2) | 1,322 (60.9) | 211 (49.0) | 1,050 (50.9) | |
| Aspirin only | 415 (9.0) | 179 (8.3) | 21 (5.8) | 215 (10.4) | |
| Other | 544 (11.8) | 189 (8.7) | 45 (12.5) | 310 (15.0) | |
| None | 304 (6.6) | 115 (5.3) | 27 (7.5) | 62 (7.8) | |
| Not recorded | 750 (16.3) | 366 (16.9) | 57 (15.8) | 327 (15.8) | |
| Mechanical VTE prophylaxis | < 0.001 | ||||
| Compression stockings (CS) | 1,249 (27.2) | 644 (29.7) | 98 (27.2) | 507 (24.6) | |
| CS + mechanical pump | 918 (20.0) | 342 (15.8) | 79 (21.9) | 497 (24.1) | |
| Foot pump only | 523 (11.4) | 324 (14.9) | 10 (2.8) | 189 (9.2) | |
| Mechanical calf pump only | 756 (16.5) | 311 (14.3) | 70 (19.4) | 375 (18.2) | |
| Other | 22 (0.5) | 4 (0.2) | 1 (0.3) | 17 (0.8) | |
| None | 378 (8.2) | 180 (8.3) | 46 (12.7) | 152 (7.4) | |
| Not recorded | 750 (16.3) | 366 (16.9) | 57 (15.8) | 327 (15.4) | |
| Head size | < 0.001 | ||||
| 28 mm | 1,864 (40.6) | 1,423 (65.6) | 198 (54.9) | 243 (11.8) | |
| 32 mm | 869 (18.9) | 510 (23.5) | 100 (27.7) | 869 (18.9) | |
| 36 mm | 1,863 (40.5) | 238 (11.0) | 63 (17.5) | 1,562 (40.5) | |
| Anesthesia | 0.01 | ||||
| Regional | 2,077 (45.2) | 987 (45.5) | 153 (42.4) | 937 (45.4) | |
| General | 827 (18.0) | 344 (15.9) | 72 (19.9) | 411 (19.9) | |
| Regional and general | 906 (19.7) | 454 (20.9) | 77 (18.2) | 375 (18.2) | |
| Not recorded | 786 (17.1) | 386 (17.8) | 59 (16.3) | 341 (16.5) | |
| Lead surgeon grade | 0.002 | ||||
| Consultant | 3,475 (75.6) | 1,600 (73.7) | 294 (81.4) | 1,581 (76.6) | |
| Other | 1,121 (24.4) | 571 (26.3) | 67 (18.6) | 483 (23.4) | |
| Position | 0.1 | ||||
| Lateral | 3,598 (78.3) | 1,708 (78.7) | 284 (78.7) | 1,606 (77.8) | |
| Supine | 248 (5.4) | 97 (4.5) | 20 (5.5) | 131 (6.4) | |
| Not recorded | 750 (16.3) | 366 (16.9) | 57 (15.8) | 327 (15.8) |
ASA: American Society of Anaesthesiologists score; PROMs: patient-reported outcomes measures.
a
Difference between groups with 1-way ANOVA (continuous data variables) or chi-squared test (categorical data variables).
b
BMI (body mass index) data on 2,726.