Table 1 Baseline characteristics of unmatched and matched patient cohorts
Patient characteristic | Unmatched cohorts | Matched cohorts | ||||
|---|---|---|---|---|---|---|
U-TKA (n = 391,855) | TA-TKA (n = 10,429) | p-Value | U-TKA (n = 8633) | TA-TKA (n = 8633) | p-Value | |
Sex—no. (%) |  |  | 0.732 |  |  | 0.826 |
 Male | 150,190 (38.3) | 4009 (38.5) |  | 3224 (37.3) | 3239 (37.5) |  |
 Female | 241,547 (61.7) | 6401 (61.5) |  | 5409 (62.7) | 5394 (62.5) |  |
Age category—no. (%) |  |  | 0.428 |  |  | 0.905 |
 18–49 | 13,580 (3.5) | 339 (3.3) | 0.236 | 143 (1.7) | 157 (1.8) | 0.415 |
 50–59 | 73,640 (18.8) | 1950 (18.7) | 0.807 | 1516 (17.6) | 1509 (17.5) | 0.889 |
 60–69 | 150,945 (38.5) | 3971 (38.1) | 0.358 | 3496 (40.5) | 3460 (40.1) | 0.576 |
 70–79 | 117,523 (30.0) | 3184 (30.5) | 0.236 | 2767 (32.1) | 2764 (32.0) | 0.961 |
 80–89 | 34,942 (8.9) | 948 (9.1) | 0.541 | 706 (8.2) | 738 (8.5) | 0.379 |
 90+ | 988 (0.3) | 33 (0.3) | 0.198 | 5 (0.1) | 5 (0.1) | 1.000 |
Race—no. (%) |  |  |  < 0.001 |  |  | 0.844 |
 White | 277,735 (70.9) | 8016 (76.9) |  < 0.001 | 7190 (83.3) | 7226 (83.7) | 0.461 |
 Hispanic | 19,923 (5.1) | 537 (5.1) | 0.766 | 272 (3.2) | 281 (3.3) | 0.697 |
 Native American or Pacific Islander | 3201 (0.8) | 44 (0.4) |  < 0.001 | 15 (0.2) | 10 (0.1) | 0.317 |
 Black/African American | 29,403 (7.5) | 582 (5.6) |  < 0.001 | 343 (4.0) | 336 (3.9) | 0.784 |
 Asian | 8164 (2.1) | 133 (1.3) |  < 0.001 | 67 (0.8) | 62 (0.7) | 0.659 |
 Unknown | 53,429 (13.6) | 1117 (10.7) | n/a | 746 (8.6) | 718 (8.3%) | n/a |
Smoking status (within 1 year)—no. (%) |  |  | 0.050 |  |  | 0.801 |
 Yes | 32,501 (8.3) | 809 (7.8) |  | 410 (4.7) | 402 (4.7) |  |
 No | 359,354 (91.7) | 9620 (92.2) |  | 8223 (95.3) | 8231 (95.3) |  |
Functional status—no. (%) |  |  |  < 0.001 |  |  | 1.000 |
 Independent | 385,003 (98.3) | 10,340 (99.1) |  < 0.001 | 8619 (99.8) | 8619 (99.8) | 1.000 |
 Partially dependent | 4601 (1.2) | 80 (0.8) |  < 0.001 | 14 (0.2) | 14 (0.2) | 1.000 |
 Totally dependent | 160 (0.0) | 3 (0.0) | 0.546 | 0 (0.0) | 0 (0.0) | n/a |
 Unknown | 2091 (0.5) | 6 (0.1) | n/a | 0 (0.0) | 0 (0.0) | n/a |
ASA classification—no. (%) |  |  |  < 0.001 |  |  | 0.108 |
 1—No disturbance | 7518 (1.9) | 134 (1.3) |  < 0.001 | 80 (0.9) | 78 (0.9) | 0.873 |
 2—Mild disturbance | 190,918 (48.7) | 5053 (48.5) | 0.586 | 4460 (51.7) | 4394 (50.9) | 0.315 |
 3—Severe disturbance | 186,442 (47.6) | 5045 (48.4) | 0.108 | 4011 (46.5) | 4104 (47.5) | 0.156 |
 4+—Life-threatening disturbance or moribund | 6532 (1.7) | 180 (1.7) | 0.241 | 82 (0.9) | 57 (0.7) | 0.033 |
 Non-assigned | 445 (0.1) | 17 (0.2) | n/a | 0 (0.0) | 0 (0.0) | n/a |
BMI—mean (SD) | 32.93 (7.10) | 32.61 (6.98) |  < 0.001 | 32.34 (6.25) | 32.36 (6.32) | 0.815 |
mFl score—mean (SD) | 0.046 (0.091) | 0.043 (0.087) |  < 0.001 | 0.035 (0.078) | 0.036 (0.079) | 0.270 |