Risk factors for postoperative deep vein thrombosis during hospitalization in patients with hip fractures: a prospective nested case-control study

This study aimed to investigate the risk factors for postoperative deep vein thrombosis (DVT) in patients with hip fractures during hospitalization to establish a foundation for early prevention and management of DVT. We conducted a prospective nested case-control study involving patients with hip fractures admitted to our hospital from January 2023 to December 2024. Patients with postoperative DVT formed the case group, while patients without DVT were matched in a 1:2 ratio according to the same department, identical fracture type, and comparable surgery duration (± 5 days) for the control group. The demographics, clinical data, and laboratory indicators were statistically evaluated in both groups. A total of 72 DVT cases and 144 controls were matched. Conditional logistic regression analysis showed that age (P<0.001, OR = 1.147), time from injury to surgery (P = 0.045, OR = 1.128), and D-dimer levels (P<0.001, OR = 1.100) were independent risk factors for postoperative DVT. The ROC curve analysis indicated that an age of 63 years, a duration of 5 days from injury to surgery, and a D-dimer level of 4.675 mg/L were the predictive thresholds for evaluating the risk of DVT. Besides, excessive sweating following antipyretic administration(meaning that sweat soaks through an entire set of hospital gowns) was associated with DVT in univariate analysis but did not reach statistical significance in the conditional logistic regression analysis (P = 0.307) and calls for additional research as an exploratory clinical indicator. Patients with hip fractures exhibit an increased prevalence of DVT. Our findings could help identify high-risk patients and enable more targeted interventions at an early stage.