Table 1.
Demographic features of 1112 patients who underwent total knee arthroplasty surgery
| Variables | Sample, N (%) | Mean ± SD | Mean LOS (days) | P-value |
|---|---|---|---|---|
| Age (years) | 67.9 ± 7.9 | 0.036 | ||
| ≤ 65 | 396 (35.7) | 7.9 ± 2.4 | ||
| >65 | 714 (64.3) | 9.5 ± 3.6 | ||
| Gender | 0.441 | |||
| Female | 927 (83.5) | 8.3 ± 4.3 | ||
| Male | 183 (16.5) | 8.0 ± 4.2 | ||
| Clinical protocol | < 0.01 | |||
| Traditional protocol | 71 (6.4) | 11.6 ± 2.3 | ||
| Current protocol | 294 (26.5) | 7.2 ± 1.9 | ||
| Operative time(min) | 89.3 ± 21.5 | < 0.01 | ||
| ≤ 70 | 253 (22.8) | 7.4 ± 4.0 | ||
| 70–110 | 646 (58.3) | 8.2 ± 4.3 | ||
| ≥ 110 | 210 (18.9) | 9.5 ± 4.2 | ||
| Surgeon | < 0.01 | |||
| 1 | 297 (26.8) | 7.9 ± 4.5 | ||
| 2 | 320 (28.9) | 8.57 ± 4.1 | ||
| 3 | 306 (27.6) | 7.4 ± 4.0 | ||
| 4 | 186 (16.8) | 10.2 ± 3.7 | ||
| ROM | 91.3 ± 18.0 | < 0.01 | ||
| <90° | 344 (35.4) | 8.6 ± 4.4 | ||
| ≥ 90° | 583 (64.6) | 7.7 ± 4.1 | ||
| Complications | < 0.01 | |||
| Yes | 220 (19.8) | 11.0 ± 4.2 | ||
| No | 892 (80.2) | 7.6 ± 4.0 | ||
| Intraoperative blood loss(ml) | 219.8 ± 120.5 | < 0.01 | ||
| ≤ 150 | 291 (41.3) | 7.7 ± 4.0 | ||
| 150–300 | 287 (40.8) | 8.2 ± 4.2 | ||
| ≥ 300 | 126 (17.9) | 10.6 ± 4.0 | ||
| Preoperative Hb(g/L) | 127.9 ± 13.7 | 0.571 | ||
| ≤ 110 | 108 (9.7) | 7.6 ± 4.4 | ||
| 110–140 | 786 (70.8) | 8.5 ± 4.3 | ||
| ≥ 140 | 116 (10.5) | 7.3 ± 4.1 | ||
| BI Score | 0.512 | |||
| ≤ 90 | 576 (67.6) | 7.3 ± 4.0 | ||
| >90 | 276 (32.4) | 7.8 ± 4.2 | ||
| Day of operation | 0.221 | |||
| Monday | 245 (22.0) | 8.3 ± 4.4 | ||
| Tuesday | 236 (21.2) | 8.9 ± 4.1 | ||
| Wednesday | 168 (15.1) | 7.6 ± 3.9 | ||
| Thursday | 212 (19.1) | 8.4 ± 4.4 | ||
| Friday | 210 (18.9) | 8.1 ± 4.0 | ||
| Type of pay | 0.412 | |||
| Selfpay | 577 (60.8) | 8.0 ± 4.1 | ||
| Medicare | 372 (39.2) | 8.2 ± 4.4 | ||
| Ward | < 0.01 | |||
| A | 923 (83.2) | 8.0 ± 4.2 | ||
| B | 186 (16.8) | 9.8 ± 4.1 | ||
| Transfusion | < 0.01 | |||
| Yes | 87 (7.8) | 11.0 ± 5.2 | ||
| No | 1025 (92.2) | 8.1 ± 4.1 | ||
| ASA classification | 0.015 | |||
| I/II | 920(82.7) | 8.1 ± 3.5 | ||
| III/IV | 192(17.3) | 9.3 ± 4.1 | ||
| Comorbidities | 0.043 | |||
| Healthy | 674 | 7.9 ± 4. | ||
| Cardiovascular | 85 | 8.5 ± 3.7 | ||
| Neurological | 93 | 9.7 ± 3.2 |
P < 0.05 was considered statistically significant. ROM Range of motion, BI Barthel Index. SD Standard deviation, Hb Hemoglobin