Challenging the Role of Routine Thromboprophylaxis in Foot and Ankle Surgery: A Comparative Study of Aspirin, Enoxaparin, and No Prophylaxis.

BACKGROUND

Deep vein thrombosis (DVT) is a common postoperative complication in orthopedic surgery and may result in life-threatening events such as pulmonary thromboembolism (PTE). However, evidence on the optimal prophylactic strategy for DVT following foot and ankle surgery remains limited. This study aimed to assess the effect of pharmacologic thromboprophylaxis in patients undergoing foot and ankle surgery with postoperative immobilization.

METHODS

A retrospective review was conducted of 451 patients who underwent foot and ankle surgery followed by short-leg splint immobilization with restricted ankle motion for more than 2 weeks between April 2022 and February 2024. All patients underwent routine screening duplex ultrasonography at 2 weeks postoperatively, regardless of symptom status. Patients were categorized into 3 groups based on postoperative pharmacologic thromboprophylaxis: no anticoagulation, aspirin (Aspirin Protect, Bayer AG) 100 mg once daily for 14 days, and enoxaparin (a low-molecular-weight heparin; Clexane, Sanofi) 40 mg once daily during hospitalization followed by aspirin after discharge to complete a total of 14 days. The incidence of DVT was compared using the chi-square test, and multivariate logistic regression analysis was performed to adjust for potential confounders.

RESULTS

Of the 451 patients, 73 patients (16.2%) developed DVT. The incidence of DVT was comparable among the 3 groups, with no statistically significant differences observed (no-anticoagulation group: 24 of 147 [16.3%]; aspirin group: 25 of 145 [17.2%]; enoxaparin group: 24 of 159 [15.1%]; p = 0.34). Most DVTs were asymptomatic (66 / 73, 90.4%) and confined to the distal calf veins (70 / 73, 95.9%), while proximal DVT was rare (3 / 73, 4.1%), occurring in 1 patient in each group. Multivariate logistic regression analysis demonstrated no significant association between pharmacologic thromboprophylaxis and postoperative DVT after adjustment for confounding variables.

CONCLUSIONS

In this retrospective cohort, pharmacologic thromboprophylaxis with enoxaparin or aspirin was not associated with a reduced incidence of postoperative DVT following foot and ankle surgery with immobilization. These findings should be interpreted cautiously given the observational design and short duration of prophylaxis. A uniform anticoagulation strategy may not be appropriate for all patients.