Abstract: Objective  Analyze the changes in serum levels of fibrinogen monomer (FM),high-density lipoprotein (HDL-C),homocysteine (Hcy),D-dimer (D-D) in patients with lower limb fractures before and after surgery,and analyze their correlation with deep vein thrombosis (DVT) .Methods 187 patients with lower limb fractures admitted from July 2020 to June 2023 were divided into DVT group (53 cases) and non DVT group (134 cases) according to the presence or absence of DVT after surgery. Independent sample ttests were used to compare the levels of serum FM, HDL-C, Hcy, and D-D between the two groups on the day before and after surgery. Spearman correlation analysis was used to investigate the correlation between serum FM, HDL-C, Hcy, D-D and DVT on the day before and after surgery. Receiver operating characteristic (ROC) curves were used to analyze the effects of serum FM, HDL-C, Hcy, and D-D on lower limbs on the day after surgery. The predictive value of postoperative DVT in fracture patients.Results Compared with 1 day before surgery,the serum FM,HDL-C,Hcy,and D-D levels in both groups increased on the day after surgery (P<0.05),and compared with the non DVT group,the DVT group had higher serum FM,HDL-C,Hcy,and D-D levels on the day after surgery (P<0.05).According to Spearman correlation analysis,there was no correlation between preoperative serum FM,HDL-C,Hcy,D-D and DVT on day 1 (P>0.05),while postoperative serum FM,HDL-C,Hcy,D-D were positively correlated with DVT on day 1 (P<0.05).ROC curve analysis showed that the AUC of FM,HDL-C,Hcy,D-D,and their combined prediction of postoperative DVT in patients with lower limb fractures on the 1st day after surgery were 0.781,0.756,0.754,0.781,and 0.879,respectively.The sensitivity and specificity corresponding to the optimal critical value were:After 1 day of surgery,the FM was 45.3% and 100.0%,the HDL-C was 100.0% and 49.3%,the Hcy was 49.1%/100.0%,and the D-D was 100.0% and 49.3%,respectively.The combined rates of the four were 83.0% and 86.6%.Conclusion Compared with patients with lower limb fractures who did not experience DVT after surgery,patients with lower limb fractures experienced elevated serum levels of FM,HDL-C,Hcy,and D-D.There was a correlation between preoperative and postoperative serum levels of FM,HDL-C,Hcy,and D-D.The combination of serum levels of FM,HDL-C,Hcy,and D-D at 1 day after surgery has a high predictive value for postoperative DVT in patients with lower limb fractures.

Key words: lower limb fractures, deep vein thrombosis, fibrin monomer, high density lipoprotein, homocysteine, D-dimer