Table 1.
Baseline characteristics of study cohorts
| Variable | Primary THA (n = 7205) |
Revision THA (n = 2515) |
Primary TKA (n = 8929) |
Revision TKA (n = 1522) |
Total (n = 20,171) |
|---|---|---|---|---|---|
| Age (mean years ± SD) | 64.0 ± 14.1 | 66.5 ± 13.9 | 67.8 ± 10.5 | 67.1 ± 11.8 | 66.2 ± 12.6 |
| Men, n (%) | 3496 (49) | 1117 (44) | 3899 (44) | 665 (44) | 9177 (45) |
| Prior operation, n (%) | 689 (10) | 2514 (100) | 2295 (26) | 1522 (100) | 7020 (35) |
| Operative time (mean minutes ± SD) | 132.9 ± 56.3 | 194.2 ± 89.6 | 143.4 ± 60.7 | 182.6 ± 79.3 | 148.9 ± 68.5 |
| ASA score, n (%) | |||||
| 1 | 353 (5) | 68 (3) | 161 (2) | 29 (2) | 611 (3) |
| 2 | 4342 (61) | 1311 (53) | 5232 (60) | 862 (58) | 11747 (59) |
| 3 | 2347 (33) | 1074 (43) | 3301 (38) | 584 (39) | 7306 (37) |
| 4 | 60 (1) | 31 (1) | 50 (1) | 12 (1) | 153 (1) |
| BMI* (mean kg/m2 ± SD) | 29.7 ± 6.3 | 29.0 ± 6.0 | 32.2 ± 6.7 | 31.8 ± 6.3 | 30.9 ± 6.6 |
| Morbid obesity*, n (%) | 476 (7) | 123 (5) | 1069 (12) | 158 (10) | 1826 (9) |
| Comorbidities†, n (%) | |||||
| Myocardial infarction | 539 (7) | 212 (8) | 821 (9) | 97 (6) | 1669 (8) |
| Congestive heart failure | 669 (9) | 243 (10) | 988 (11) | 124 (8) | 2024 (10) |
| Peripheral vascular disease | 717 (10) | 200 (8) | 1011 (11) | 100 (7) | 2028 (10) |
| Cerebrovascular disease | 928 (13) | 268 (11) | 1368 (15) | 158 (10) | 2722 (13) |
| Dementia | 69 (1) | 25 (1) | 77 (1) | 11 (1) | 182 (1) |
| Pulmonary disease | 1059 (15) | 315 (13) | 1695 (19) | 217 (14) | 3286 (16) |
| Ulcers | 636 (9) | 187 (7) | 1092 (12) | 135 (9) | 2050 (10) |
| Mild liver disease | 230 (3) | 85 (3) | 446 (5) | 41 (3) | 802 (4) |
| Severe liver disease | 53 (1) | 23 (1) | 137 (2) | 8 (1) | 221 (1) |
| Diabetes mellitus | 1087 (15) | 320 (13) | 1829 (20) | 271 (18) | 3507 (17) |
| Diabetes with organ damage | 300 (4) | 73 (3) | 564 (6) | 55 (4) | 992 (5) |
| Hemiplegia | 68 (1) | 21 (1) | 98 (1) | 7 (0) | 194 (1) |
| Renal disease | 879 (12) | 274 (11) | 1267 (14) | 149 (10) | 2569 (13) |
| Metastatic tumors | 407 (6) | 96 (4) | 559 (6) | 59 (4) | 1121 (6) |
| Rheumatologic disease | 564 (8) | 266 (11) | 797 (9) | 136 (9) | 1763 (9) |
| Cancer | 1613 (22) | 389 (15) | 2331 (26) | 248 (16) | 4581 (23) |
* BMI defined using actual patient height and weight measurements at time of surgery. Morbid obesity = BMI > 40 kg/m2; †Comorbidities defined per the Charlson comorbidity index; ASA = American Society of Anesthesiologists.