Incidence and Hematological Biomarkers Associated With Preoperative Deep Venous Thrombosis Following Foot Fractures

Background: This study was designed to investigate the incidence and hematological biomarker levels that are associated with deep venous thrombosis (DVT) following closed foot fractures (except calcaneal fractures).

Methods: A retrospective analysis of data on patients presenting with closed foot fractures (excluding the calcaneus) between October 2014 and December 2018 was conducted. Duplex ultrasonography was used to screen preoperative DVT of bilateral lower extremities. Data on demographics, comorbidities, types of fracture, and laboratory biomarkers at admission were collected. Univariate analyses and multivariate logistic regression analyses were carried out to determine the independent risk factors associated with DVT.

Results: A total of 537 patients were included, among whom 28 patients had preoperative DVTs, indicating a crude incidence rate of 5.2%. In isolated closed foot fractures, DVT occurred in 12 (2.9%) out of 410 patients, while in patients with concurrent fracture in other locations, 16 (12.6%) out of 127 patients developed DVT. The average interval between fracture occurrence and diagnosis of DVT was 4.2 days (median, 2 days), ranging from 0 to 17 days. Twenty-four patients (85.7%) developed DVT in the injured extremity, 3 (10.7%) in the uninjured extremity, and 1 (3.5%) in bilateral extremities. Seven risk factors were identified to be associated with DVT, including alcohol consumption, concomitant other fractures, platelet distribution width (PDW) <12%, high-density lipoprotein cholesterol (HDL-C) <1.1mmol/L, serum alkaline phosphatase (ALP) >100 U/L, serum sodium concentration (Na⁺) <135 mmol/L, and D-dimer >0.5 mg/L.

Conclusion: Being aware of the prevalence of DVT in closed foot fractures can help physicians to carry out the overall assessment, risk stratification, and individual prevention programs.

Level of evidence: Level III, a prospective cohort study.

Keywords: closed foot fractures; deep venous thrombosis; risk factors.