D-Dimer Variability Predicts Venous Thromboembolism in Postoperative Fracture Patients: A Single-Center Retrospective Cohort Study.

BackgroundVenous thromboembolism (VTE) is a potentially life-threatening complication following traumatic fractures. Although plasma D-dimer is widely used as a biomarker of coagulation and fibrinolysis, its utility as a standalone predictor of postoperative VTE remains limited due to poor specificity. This study aimed to investigate whether D-dimer variability is a more accurate predictor of VTE compared to D-dimer alone.MethodsDemographic data, fracture classification, and D-dimer levels were collected. D-dimer variability was defined as the ratio of postoperative D-dimer to preoperative D-dimer. Duplex ultrasonography was used to evaluate DVT in the lower extremities, while computed tomography pulmonary angiography was conducted for patients suspected of having pulmonary thromboembolism (PTE).ResultsA total of 77,609 traumatic fracture patients without VTE [median age: 53.00 (44.00, 61.00) years] and 2,813 patients with VTE [median age: 66.00 (58.00, 75.00) years] were included. Among VTE cases, 36 sustained upper limb or craniofacial fractures, 522 spinal fractures, 269 pelvic fractures, 1265 lower limb fractures, and 721 compound or other fractures. Specifically, 2743 patients developed lower extremity VTE, and 70 suffered from PTE. Postoperative D-dimer variability was significantly higher in patients with VTE (2.30 [1.57, 3.43]) than in those without VTE (1.33 [0.77, 2.15]). At a D-dimer variability cutoff of 2.0, the sensitivity and specificity were 83.44% and 88.60%, respectively. Multivariate analysis identified age > 60 years, female sex, and lower extremity fractures as independent VTE risk factors.ConclusionsThe D-dimer variability is strongly correlated with VTE in postoperative traumatic fracture patients. D-dimer variability ≥2.0 may identify a subgroup of postoperative fracture patients at elevated VTE risk. It serves as a useful predictor of VTE, particularly in elderly patients, females, and those with lower extremity fractures.