Silent Threats After Surgery: Incidence and Predictors of Deep Vein Thrombosis and Pulmonary Embolism in Orthopedic Patients

<b>Objectives</b>: This study aimed to determine the incidence of postoperative deep vein thrombosis (DVT) and pulmonary embolism (PE) following orthopedic surgeries and to identify independent clinical, laboratory, and procedural factors associated with thromboembolic risk. <b>Materials and Methods</b>: A retrospective cohort analysis was conducted on 300 patients who underwent elective or emergency orthopedic surgeries (hip/knee arthroplasty, fracture fixation, and spinal procedures) between January 2020 and December 2024 at two tertiary centers. Demographic, clinical, and biochemical data were collected. Patients were stratified into two groups: those who developed DVT/PE and those who did not. Univariate analyses were performed to identify significant factors, and a multivariate logistic regression model with stepwise variable selection was applied in accordance with the events-per-variable (EPV) criterion. Receiver operating characteristic (ROC) curve analyses were conducted to evaluate the discriminative performance of significant predictors. <b>Results</b>: Among 300 patients who underwent orthopedic surgery, postoperative deep vein thrombosis (DVT) and/or pulmonary embolism (PE) occurred in 50 cases (16.7%). Patients who developed thromboembolic events were older (72.5 ± 8.7 vs. 65.2 ± 10.1 years, <i>p</i> < 0.001), had higher body mass index (32.1 ± 5.3 vs. 28.3 ± 4.5 kg/m², <i>p</i> < 0.001), and showed a greater prevalence of diabetes mellitus (40% vs. 20%, <i>p</i> < 0.01) and chronic kidney disease (24% vs. 10%, <i>p</i> < 0.001) compared to those without DVT/PE. Laboratory analyses revealed significantly elevated neutrophil count, D-dimer, C-reactive protein (CRP), glucose, and troponin levels in the DVT/PE group. In the stepwise multivariate logistic regression model, age (OR = 1.44, <i>p</i> = 0.003), diabetes mellitus (OR = 2.88, <i>p</i> = 0.046), chronic kidney disease (OR = 2.33, <i>p</i> = 0.014), D-dimer (OR = 2.15, <i>p</i> = 0.019), and immobilization duration (OR = 2.21, <i>p</i> = 0.028) emerged as independent predictors of thromboembolic events. ROC analysis revealed that D-dimer > 0.9 mg/L had the highest discriminative performance (AUC = 0.89, sensitivity 88%, specificity 84%, <i>p</i> = 0.003), followed by troponin > 0.5 U/L (AUC = 0.86, <i>p</i> = 0.005), immobilization > 3 days (AUC = 0.82, <i>p</i> = 0.012), and age > 65 years (AUC = 0.74, <i>p</i> = 0.021). <b>Conclusions</b>: DVT and PE remain significant postoperative complications with a multifactorial etiology in orthopedic surgeries. Advanced age, comorbidities (such as diabetes mellitus and chronic kidney disease), and elevated inflammatory and metabolic markers (including neutrophil count, glucose, CRP, and D-dimer), together with procedural factors like prolonged immobilization, were identified as independent risk factors. Early recognition of these high-risk features and implementation of individualized prophylaxis strategies may improve postoperative outcomes and reduce thromboembolic risk.