Table 2.
Baseline demographic and clinical characteristics of the study population.
| Variable | UTKA (n = 754) | SSBTKA (n = 380) | Total (n = 1134) | p value∗ (UTKA vs. SSBTKA) | |
|---|---|---|---|---|---|
| Side† | Right | 406(53.8) | 380(50) | 786(51.9) | 0.134 |
| Left | 348(46.2) | 380(50) | 728(48.1) | ||
| Sex | Male | 286(37.9) | 81(21.3) | 367(32.4) | <0.001 |
| Female | 468(62.1) | 299(78.7) | 767(67.6) | ||
| OA/RA | OA | 701(93) | 353(92.9) | 1054(92.9) | 0.962 |
| RA | 53(7) | 27(7.1) | 80(7.1) | ||
| Age, years | 62.91 ± 9.09 | 63.56 ± 8.62 | 63.13 ± 8.93 | 0.249 | |
| Age distribution | <65 years | 441 (58.5) | 201 (52.9) | 640 (56.4) | 0.079 |
| ≥65 years | 313 (41.6) | 179 (47.1) | 492 (43.6) | ||
| Comorbidities | Diabetes mellitus | 169(22.4) | 85 (22.4) | 254 (22.4) | 0.986 |
| Cardiac comorbidity | 82 (10.9) | 41 (10.8) | 123 (10.8) | 0.965 | |
| Hypertension | 172 (22.8) | 88 (23.2) | 260 (22.9) | 0.896 | |
| COPD | 20 (2.7) | 9 (2.4) | 29 (2.6) | 0.775 | |
| ASA physical status | Grade I | 368 (48.8) | 187 (49.2) | 555 (48.9) | 0.986 |
| Grade II | 353 (46.8) | 176 (46.3) | 529 (46.7) | ||
| Grade III | 33 (4.4) | 17 (4.5) | 50 (4.4) | ||
| Hemoglobin level, g/dL | 12.82 ± 1.21 | 12.82 ± 1.21 | 12.82 ± 1.21 | 0.942 | |
| OKS† | 15.16 ± 2.93 | 14.11 ± 2.98 | 14.63 ± 3.0 | <0.001 | |
| WOMAC† | 44.19 ± 4.77 | 44.21 ± 4.85 | 44.20 ± 4.81 | 0.923 | |
Data are presented as mean ± standard deviation for quantitative variables and number (percentage) for categorical variables. ∗p < 0.05 was considered statistically significant. The independent t-test was used for quantitative variables and the Chi Square test for categorical variables. †For this variable, the sample size was considered as 760 for the SSBTKA group (i.e. the total number of knees). UTKA: Unilateral total knee arthroplasty; SSBTKA: Simultaneous sequential bilateral total knee arthroplasty; OA: Osteoarthritis; RA: Rheumatoid arthritis; COPD: Chronic obstructive pulmonary disease; ASA: American Society of Anesthesiologists; OKS: Oxford Knee Score; WOMAC: Western Ontario and McMaster Universities Osteoarthritis Index.