ALB and deep vein thrombosis: The seven variables were entered into the final model of the multivariate analysis and three variables were identified to be independent risk factors of the preoperative DVT in closed isolated patella fracture, including age ≥ 65years old, (OR, 3.0, 95% CI, 1.1–8.1), D-dimer > 0.5 mg/L, (OR, 2.3, 95% CI, 1.1–4.8), and albumin < 35 g/L, (OR, 2.5, 95% CI, 1.2–5.3), (Table 2).