Table 3.
Univariate and multivariate analysis of patient variables associated with need for manipulation under anesthesia
| Variable | Unadjusted HR | 95% CI | p-value | Adjusted HR | 95% CI | p-value |
|---|---|---|---|---|---|---|
| Patient Characteristics | ||||||
| Sex | ||||||
| Female | 1.06 | 0.85 – 1.31 | 0.63 | 1.13 | 0.88 – 1.44 | 0.34 |
| Male (reference) | ||||||
| Age | ||||||
| < 65 years | 2.79 | 2.24 – 3.47 | <0.001 | 2.81 | 2.16 – 3.64 | <0.001 |
| ≥ 65 years (reference) | ||||||
| Body mass index | ||||||
| ≥ 30 kg/m2 | 0.88 | 0.71 – 1.09 | 0.23 | 0.74 | 0.57 – 0.95 | 0.02 |
| < 30 kg/m2 (reference) | ||||||
| Indication for TKA | ||||||
| Post-traumatic arthritis | 2.69 | 2.08 – 3.48 | <0.001 | 1.68 | 1.25 – 2.27 | <0.001 |
| Osteoarthritis (reference) | ||||||
| Smoking status | ||||||
| Current | 1.54 | 1.01 – 2.34 | 0.04 | – | – | – |
| Never (reference) | ||||||
| Prior knee surgery | ||||||
| Yes | 1.79 | 1.44 – 2.24 | <0.001 | – | – | – |
| No (reference) | ||||||
| Surgical Characteristics | ||||||
| Unilateral or Bilateral TKAs | ||||||
| Simultaneous bilateral | 0.66 | 0.46 – 0.96 | 0.03 | 0.78 | 0.70 – 0.88 | <0.001 |
| Staged bilateral | 0.45 | 0.33 – 0.61 | <0.001 | – | – | – |
| Unilateral (reference) | ||||||
| Anesthesia | ||||||
| General | 1.49 | 1.20 – 1.85 | <0.001 | 1.36 | 1.06 – 1.73 | 0.02 |
| Neuraxial (reference) | ||||||
| Tourniquet time, min | 1.01 | 1.01 – 1.01 | <0.001 | 1.01 | 1.00 – 1.01 | <0.001 |
| Operative time, min | 1.00 | 1.00 – 1.00 | 0.005 | 1.00 | 1.00 – 1.00 | 0.55 |
| Comorbidities^ | ||||||
| Diabetes | 1.10 | 0.88 – 1.42 | 0.49 | 1.49 | 1.11 – 1.99 | 0.01 |
| Hypertension | 0.51 | 0.41 – 0.63 | <0.001 | 0.74 | 0.57 – 0.97 | 0.03 |
| Renal disease† | 0.43 | 0.26 – 0.69 | 0.001 | 0.57 | 0.34 – 0.95 | 0.03 |
| Peripheral vascular disease | 0.60 | 0.44 – 0.81 | 0.001 | – | – | – |
| Liver disease† | 1.46 | 0.78 – 2.73 | 0.24 | – | – | – |
| Metastatic solid tumor | 0.90 | 0.50 – 1.59 | 0.71 | – | – | – |
| Congestive heart failure | 0.49 | 0.30 – 0.78 | 0.003 | – | – | – |
| Rheumatologic disease | 0.75 | 0.50 – 1.12 | 0.16 | – | – | – |
| Myocardial infarct | 0.67 | 0.43 – 1.06 | 0.09 | – | – | – |
| Other cancer | 0.80 | 0.60 – 1.06 | 0.12 | – | – | – |
| Cerebrovascular disease | 0.72 | 0.50 – 1.04 | 0.08 | – | – | – |
| Dementia | 0.58 | 0.26 – 1.30 | 0.19 | – | – | – |
| Chronic pulmonary disease | 0.91 | 0.71 – 1.16 | 0.44 | – | – | – |
| Mild liver disease | 1.13 | 0.81 – 1.57 | 0.49 | – | – | – |
| Diabetes with organ damage | 0.90 | 0.57 – 1.41 | 0.63 | – | – | – |
| Ulcer | 0.83 | 0.55 – 1.26 | 0.38 | – | – | – |
| CCI | 0.40 | 0.32 – 0.49 | <0.001 | – | – | – |
*
HR = Hazard Ratio; CI = Confidence Interval; TKA = Total Knee Arthroplasty; CCI = Charlson Comorbidity Index
^
Absence of disease served as reference for comorbidity data
†
Moderate or severe disease