Abstract:Objective This study aimed to analyze the risk factors for lower extremity deep vein thrombosis (DVT) in patients with tibiofibular fractures after treatment with open reduction and plate internal fixation.Methods The study subjects were 127 patients with tibiofibular fractures admitted to our hospital from January 2022 to January 2025. All patients underwent open reduction and plate internal fixation, and were divided into the DVT group (36 cases) and non-DVT group (91 cases) based on the presence or absence of postoperative lower extremity DVT. General data of patients in both groups were collected. Peripheral venous blood samples were taken before surgery to detect biochemical indicators, C-reactive protein (CRP), fibrinogen (FIB), activated partial thromboplastin time (APTT), and D-dimer. Logistic regression analysis was used to screen for risk factors of postoperative DVT, a nomogram prediction model was constructed, and the fitting effect of the model was evaluated.Results Patients in the DVT group were older than those in the non-DVT group (P < 0.05). The time from injury to surgery and the time to first postoperative ambulation were both longer in the DVT group (P < 0.05). Hematocrit, CRP, and D-dimer levels were higher, while APTT levels were lower in the DVT group compared with the non-DVT group (all P < 0.05). Multivariable stepwise logistic regression analysis showed that older age [O^R = 1.177 (95% CI: 1.038, 1.335) ], higher preoperative D-dimer level [O^R = 1.032 (95% CI: 1.020, 1.044)], higher hematocrit [O^R = 1.213 (95% CI: 1.051, 1.401) ], and delayed first postoperative ambulation [O^R = 1.272 (95% CI: 1.058, 1.530) ] were independent risk factors for postoperative DVT (P < 0.05), whereas higher APTT level [O^R = 0.809 (95% CI: 0.686, 0.953) ] was a protective factor (P < 0.05). Bootstrap validation demonstrated good predictive performance of the nomogram model, with a mean absolute error of 0.039 and a C-index of 0.853 (95% CI: 0.791, 0.913), indicating good discrimination ability.Conclusion A nomogram prediction model incorporating key factors, including advanced age, elevated preoperative D-dimer, increased hematocrit, and delayed first postoperative ambulation, was developed in this study. This model provides an important tool for early identification of high-risk patients, targeted use of lower extremity vascular ultrasound, and the formulation of individualized preventive strategies in clinical practice.