Table 1.
Demographics and surgical factors
| Baseline data | LOS ≤ 3 (n = 196) | LOS > 3 (n = 115) | P value |
|---|---|---|---|
| Demographic characteristics | |||
| Age (years) | 55.7 ± 13.4 | 53.6 ± 16.2 | 0.243 |
| Gender (female)* | 90 (45.9%) | 75 (65.2%) | 0.001 |
| BMI (kg/m2) | 23.1 ± 3.5 | 23.7 ± 4.0 | 0.210 |
| Living situation (living alone)* | 10 (5.1%) | 21 (18.3%) | <0.001 |
| Preoperative HHS | 55.6 ± 10.6 | 53.9 ± 13.4 | 0.251 |
| Operation history of involved hip | 10 (5.1%) | 10 (8.7%) | 0.212 |
| Diagnosis* | 0.020 | ||
| ONFH | 90 (45.9%) | 35 (33.4%) | ‐ |
| DDH | 69 (35.2%) | 36 (31.3%) | ‐ |
| Primary osteoarthritis | 13 (6.6%) | 16 (13.9%) | ‐ |
| Suppurative arthritis | 7 (3.6%) | 12 (10.4%) | ‐ |
| Rheumatoid arthritis | 4 (2.0%) | 4 (3.5%) | ‐ |
| Fracture of femoral neck | 4 (2.0%) | 5 (4.3%) | ‐ |
| Legg‐Calve‐Perthes disease | 6 (3.1%) | 5 (4.3%) | ‐ |
| Ankylosing spondylitis | 3 (1.5%) | 2 (1.7%) | ‐ |
| Laboratory values | |||
| Preoperative HB* | 135.8 ± 15.9 | 130.1 ± 16.2 | 0.002 |
| Postoperative HB* | 115.4 ± 15.2 | 108.3 ± 15.6 | <0.001 |
| Preoperative albumin | 44.9 ± 4.3 | 44.4 ± 4.4 | 0.346 |
| Postoperative albumin | 36.7 ± 3.8 | 36.2 ± 3.6 | 0.258 |
| Operative variables | |||
| Catheter use | 13 (6.6%) | 8 (7.0%) | 0.913 |
| Drain use* | 6 (3.1%) | 12 (10.4%) | 0.007 |
| Estimated blood loss (mL) | 662.8 ± 471.0 | 672.5 ± 448.0 | 0.859 |
| Blood transfusion* | 1 (0.5%) | 4 (3.5%) | 0.064 |
BMI, body mass index; DDH, developmental dysplasia of hip; HB, hemoglobin; HHS, Harris Hip Score; ONFH, osteonecrosis of femoral head.
*
Variables with P value < 0.1 were further included in the multivariate logistic regression model.