| Baseline Characteristics | TKA | KAR | P value |
| n = 5.879 | n = 482 | ||
| Group, age------ no. (%) | |||
| 18 - 39 yr. | 31 (0.5) | 4 (0.8) | 0.014 |
| 40 - 49 yr. | 96 (1.6) | 12 (2.5) | 0.014 |
| 50 - 59 yr. | 795 (13.5) | 77 (16.0) | 0.014 |
| 60 - 69 yr. | 2236 (38.0) | 162 (33.6) | 0.014 |
| 70 - 79 yr. | 2149 (36.6) | 162 (33.6) | 0.014 |
| ≥80 yr. | 572 (9.7) | 65 (13.5) | 0.014 |
| Gender------no. (%) | |||
| Male | 1669(28.9) | 164(34.0) | 0.020 |
| Coexistent diseases------ no. (%) | |||
| Arterial hypertension | 4177 (71.0) | 330 (68.5) | 0.251 |
| Diabetes mellitus | 1184 (20.1) | 114 (23.7) | 0.075 |
| Connective tissue disorder | 437 (7.4) | 61 (12.7) | <0.001 |
| Chronic pulmonary disease | 398 (6.8) | 45 (9.3) | 0.042 |
| Myocardial infarction | 177 (3.0) | 8 (1.7) | 0.120 |
| Dementia | 92 (1.6) | 9 (1.9) | 0.748 |
| Cerebrovascular disease | 80 (1.4) | 13 (2.7) | 0.031 |
| Peripheral vascular disease | 38 (0.6) | 3 (0.6) | <1.000 |
| HIV/AIDS | 33 (0.6) | 2 (0.4) | 0.922 |
| Congestive heart failure | 31 (0.5) | 3 (0.6) | <1.000 |
| Kidney disease | 23 (0.4) | 4 (0.8) | 0.289 |
| Cancer | 21 (0.4) | 3 (0.6) | 0.598 |
| Liver disease | 5 (0.1) | 3 (0.6) | 0.011 |
| Plegía | 1 (0.0) | 0 (0.0) | <1.000 |
| Death | 91(1.5) | 13(2.7) | 0.084 |